At the end of a glacier deep in East Antarctica's Taylor Valley, there is a haunting waterfall that oozes red brine like a bleeding wound in the ice. Scientists explained the brine's gory hue several years ago, finding that it is exceptionally rich in iron. And now, they may have identified the salty water's origin.

Microbes in the crimson waterfall, called Blood Falls, suggest the brine is composed of ancient seawater that was trapped in a pool beneath the glacier when ocean levels fell and the glacier advanced. However, it's unclear exactly when that happened, researchers noted. Previous studies had already proposed a seawater origin for the brine, based on various chemical signatures and bacteria detected in the liquid, but the new results add molecular and genetic evidence to the mix of clues.

"Findings in this study reveal a dominance of marine eukaryotic lineages in the Blood Falls area" compared with the broader region, known as the McMurdo Dry Valleys, the authors wrote in the study, published Monday (Aug. 3) in the journal Nature Geoscience. "This marine signal is less prominent but still detectable in the prokaryotic structure," the researchers added.

Eukaryotes' cells contain a membrane-bound nucleus and other closed internal compartments. Prokaryotes, by contrast, are single-celled organisms whose DNA floats around freely in the cell, unbounded by a membrane.

To characterize the types of microorganisms present within Blood Falls, the researchers used a suite of genetic techniques to analyze 167 samples of water, sediment and air from around the falls and the broader McMurdo Dry Valleys.

Some researchers argue that Blood Falls' water does not originate from seawater, and suggest the marine bacteria and chemical signatures that point to seawater may have instead reached the falls from the ocean via intense winds, which are common in the McMurdo Dry Valleys. By analyzing samples from various sites in the Dry Valleys, the team behind the new study compared microorganisms from the wider region with those at Blood Falls to determine if Blood Falls has a distinct microbial assemblage potentially left over from ancient conditions.

The researchers found that the crimson brine and associated red-tinted sediments at Blood Falls shared a higher proportion of eukaryotes with nearby oceanic samples than other sites in the Dry Valleys did. Whereas Blood Falls had a little over 9% of its eukaryotes in common with the ocean, the Dry Valleys showed only about 1% similarity, according to the study. The remaining eukaryotes and most of the prokaryotes identified in the paper had freshwater and terrestrial origins.

The results also showed that the air near Blood Falls contained only a tiny proportion of marine microorganisms, suggesting that present-day winds can't fully explain the microbial composition of Blood Falls, the researchers wrote.

Therefore, an ancient seawater origin is the most likely explanation for the microorganisms found at Blood Falls today, the team concluded. Winds may have played a role in shaping the community in the past, but now, their influence is probably insignificant, the team added.

The brine that feeds Blood Falls may have become entrapped more than 1 million years ago, during a warm period with higher sea levels and less ice cover than there is now, previous estimates suggested. However, further work, including more comprehensive genetic profiling and mapping of microorganisms, is needed to pinpoint when Taylor Valley's glacier grew to cover the brine, the researchers wrote.

Antarctica quiz: Test your knowledge on Earth's frozen continent

Microbes that have been suspended in permafrost for up to 40,000 years could "reawaken" and start churning out greenhouse gases if Arctic summers grow much longer, new research suggests.

Under future climate conditions, microbes that have been dormant since the last ice age (2.6 million to 11,700 years ago) may only need a few months to reactivate, according to a study published Sept. 23 in the Journal of Geophysical Research: Geosciences. If they do so for even a part of the year, scientists warn this could trigger a feedback loop that would accelerate permafrost thaw and global warming.

Permafrost is a mix of soil, rocks and ice that has been frozen solid for at least two years straight. A hot spell may thaw the topmost layer of permafrost, known as the active layer, but ancient microbes lurk much deeper down, in layers that thaw only if temperatures rise significantly and for extended periods. For the new study, researchers traveled to Alaska, where permafrost underlies 85% of the land.

"You might have a single hot day in the Alaskan summer, but what matters much more is the lengthening of the summer season to where these warm temperatures extend into the autumn and spring," study lead author Tristan Caro, a postdoctoral research associate in geobiology at Caltech, said in a statement.

Caro and his colleagues collected samples from the Permafrost Research Tunnel near Fairbanks. The tunnel sits 50 feet (15 meters) below ground and extends more than 350 feet (107 m) into the permafrost, offering a glimpse into life during the late Pleistocene epoch (129,000 to 11,700 years ago).

Their aim was to determine resuscitation and growth rates in microbes that lived during this time. But as Caro entered the tunnel, he also noticed mammoth and bison bones protruding from the icy walls, according to the statement.

"The first thing you notice when you walk in there is that it smells really bad," said Caro, who conducted the research as a graduate student at the University of Colorado Boulder. "To a microbiologist, that's very exciting because interesting smells are often microbial."

Back in the lab, the researchers drenched the samples in water containing unusually heavy hydrogen atoms, also known as deuterium. They then incubated the samples in refrigerators set to 25, 39 or 54 degrees Fahrenheit (minus 4, 4 and 12 degrees Celsius) and regularly examined them for changes in microbial activity.

"We wanted to simulate what happens in an Alaskan summer, under future climate conditions where these temperatures reach deeper areas of the permafrost," Caro said.

One month into the experiment, the team didn't note much change, even in the two warmer samples. A handful of microbes had awakened from their long slumber, but only 0.001% to 0.01% of cells were replaced daily by new, active ones.

In the months that followed, however, everything changed. The deuterium in the samples enabled the researchers to track how much water microbes consumed to build the fatty membranes around their cells. This revealed that the ancient organisms preferentially produced fatty acids called glycolipids, which researchers think may be involved in cryopreservation.

Six months into the experiment, the microbes incubated at 39 F and 54 F had undergone "dramatic" changes in community structure and activity levels, according to the study. The samples were less diverse than active layers of permafrost, but the microbes were as active as their more modern counterparts, even producing slimy structures called biofilms that were visible to the naked eye.

"These are not dead samples by any means," Caro said.

The results have implications for the Arctic and Earth's climate more broadly, because microbes in the permafrost survive on organic matter, which they convert into carbon dioxide and methane. Global temperatures are rising faster in the Arctic than anywhere else in the world, thawing the permafrost at alarming rates and for increasing lengths of time. As Arctic summers grow longer and temperatures rise in the deeper layers, colonies of ancient microbes could awaken and start emitting carbon.

Permafrost in northern regions currently holds about twice as much carbon as Earth's atmosphere, so large-scale releases could contribute significantly to climate change. This would accelerate permafrost thaw, triggering a vicious cycle of warming, more thaw and more warming.

"It's one of the biggest unknowns in climate responses," study co-author Sebastian Kopf, an associate professor of geological sciences at the University of Colorado Boulder, said in the statement. "How will the thawing of all this frozen ground, where we know there's tons of carbon stored, affect the ecology of these regions and the rate of climate change?"

But the study only examined ancient microbes from one location, and microbes in other regions may react differently to warming, the researchers noted.

"There's so much permafrost in the world — in Alaska, Siberia and in other northern cold regions," Caro said. "We've only sampled one tiny slice of that."

Australia's pink lakes are bodies of water that harbor rare, pigment-producing microbes. The lakes are about 10 times saltier than the ocean, attracting algae and bacteria that churn out beta-carotene — a red-orange pigment that also gives carrots, crayfish and flamingos their characteristic colors.

Most of the country's pink lakes are found in Western Australia, which has around a dozen. The lakes are the remnants of rivers that flowed across the landscape more than 15 million years ago, which makes them thousands of years old, according to National Geographic.

As the ancient rivers dried up, pockets of water were left over and partially evaporated over time, concentrating salt and attracting salt-loving microorganisms such as Dunaliella salina and Salinibacter ruber — which are single-celled algae and red bacteria, respectively. D. salina and S. ruber produce beta-carotene when exposed to sunlight, turning the lakes different shades of pink depending on salt levels. Beta-carotene protects these microorganisms from ultraviolet rays and absorbs light energy, enabling them to thrive and reproduce, according to National Geographic.

But pink lakes are fragile because changes in salinity can upset their regular inhabitants. Heavy rainfall, for example, can dilute the lakes' salt content to the extent that photosynthetic algae completely replace D. salina and S. ruber.

This recently happened at Lake Hillier on Western Australia's Middle Island, according to ABC News. Lake Hillier previously harbored a wide array of pigment-producing microbes, but extreme rainfall due to climate change in 2022 disturbed this community. As a result, the lake turned from pink to blue-gray — but experts think it could recover within the next 10 years if salinity returns to its previous levels.

Related: Lake Natron: The caustic, blood-red lake in Tanzania that turns animals to 'stone'

Lake Hillier is not the only pink lake to have lost its rosy tint. Pink Lake, situated near Esperance in Western Australia, turned blue-gray in the 2000s after a century of salt mining. Salt was extracted to make table salt, salt licks for livestock, and preservatives for meat and hides, according to National Geographic. By the early 2000s, there was not enough salt left in Pink Lake for species like D. salina and S. ruber to survive. As photosynthetic algae took over, the change in color was so dramatic that locals lobbied for the lake to be renamed.

Unlike Lake Hillier, experts don't think that Pink Lake will recover naturally any time soon — but scientists have suggested artificially pumping salt from nearby salt lakes into Pink Lake to return it to pre-mining levels.

Pink lakes are feeding grounds for nomadic and migratory birds, and they host invertebrates like brine shrimp and salt lake snails, which makes them valuable ecosystems. Extreme environments like pink lakes also help scientists to understand the potential for life on Mars.

"They still produce some of the toughest organisms on the planet," Angus Lawrie, a conservation biologist and research associate at Curtin University in Australia, told National Geographic.

Discover more incredible places, where we highlight the fantastic history and science behind some of the most dramatic landscapes on Earth.

After 15 years of debate, a study that announced the alleged discovery of an arsenic-eating microbe has been retracted by the journal Science due to contaminated and flawed data. However, the original study authors disagree with the move.

The microbe strain, labeled GFAJ-1, was recovered from the salty water of arsenic-rich Mono Lake in California by a research team led by Felisa Wolfe-Simon of NASA's Astrobiology Institute.

Wolfe-Simon and colleagues grew GFAJ-1 in petri dishes while replacing phosphorus — a crucial component of DNA — with arsenic, which is usually highly toxic to living organisms, they reported. The team published their findings in the journal Science in 2010.

Before the paper came out, NASA hyped the finding by telling the media it would hold a news conference "to discuss an astrobiology finding that will impact the search for evidence of extraterrestrial life." Soon after, the GFAJ-1 microbe discovery quickly went viral, and it was hailed as a breakthrough in astrobiology. It upended biologists' understanding of the basic requirements for life, ostensibly proving that "arsenic life" was possible.

"What we've found is a microbe doing something new — building parts of itself out of arsenic," Wolfe-Simon said in a 2010 NASA statement. "If something here on Earth can do something so unexpected, what else can life do that we haven't seen yet?"

But critiques of the study quickly flowed in, and by the time Science published the paper in a 2011 print issue, the original study was accompanied by eight technical comments from outside experts pointing out key scientific flaws in the methods and interpretations.

Related: What's the best evidence we've found for alien life?

In 2012, two studies published in Science tried to replicate the arsenic-eating findings of Wolfe-Simon and colleagues. Both studies determined that GFAJ-1 could tolerate high levels of arsenic but could not use it instead of phosphorus as a building block for life.

Although the controversial "arsenic life" study was never replicated, it was not retracted because there was no deliberate fraud or misconduct. But in the past five years, Science has begun retracting papers for reasons other than fraud and misconduct. On Thursday (July 24), Science decided to officially retract the study by Wolfe-Simon and colleagues.

"One of the Technical Comments had pointed out that the nucleic acids that were analyzed were not sufficiently purified," Valda Vinson, executive editor of the Science journals, and Holden Thorp, editor-in-chief of the Science journals, wrote in a blog post. "Given the evidence that the results were based on contamination, Science believes that the key conclusion of the paper is based on flawed data."

The study's authors, however, do not support the retraction.

"Disputes about the conclusions of papers, including how well they are supported by the available evidence, are a normal part of the process of science," they wrote in an eLetter, also published Thursday. "While our work could have been written and discussed more thoroughly, we stand by the data as reported."

Periodic table of elements quiz: How many elements can you name in 10 minutes?

Scientists are deep-freezing human poop in a "doomsday" vault in Switzerland that already contains more than 1,000 fecal samples, and the researchers now say they want to amass 10,000 samples by 2029.

That's because poop contains billions of microbes that scientists want to preserve in case future generations need the bugs to solve medical and other health crises, according to a commentary published Friday (June 27) in the journal Nature Communications. The Swiss storage facility also houses almost 200 types of fermented food, which contain plenty of "gut-friendly" microbes that could help keep populations healthy, and the team plans to add environmental microbes to the collection.

The aim over the long term is to have backup copies of microbes that live in humans, animals, plants and the environment so that future generations can conduct research, restore ecosystems and invent medical treatments as needed.

"Microbe loss is associated with an alarming rise in chronic diseases, such as allergic, autoimmune and metabolic disorders," the researchers wrote in the commentary. "The loss of microbial diversity extends to environmental ecosystems, jeopardizing agricultural systems and environmental resilience."

There is a need to preserve all types of microbes, because human activities are responsible for the disruption of the microbiomes, or microbial communities, of humans, animals and the environment, the authors argue. For example, conventional agriculture, the thawing of permafrost due to human-caused climate change, and the overuse of antibiotics are eroding microbiomes so much that they might need to be rescued in the future, the team wrote.

Related: 8 ancient 'zombie viruses' that scientists have pulled from the melting permafrost

"Human activities are depleting our microbiome, and there's lots of evidence of that," Dr. Martin Blaser, director of the Center for Advanced Biotechnology and Medicine at Rutgers University in New Jersey and co-author of the new commentary, said in a statement.

There is currently no proof that reintroducing frozen microbes into a human gut or ecosystem can restore it, but "we believe that one day the science will improve sufficiently so that we will have really good restorative techniques," Blaser said.

The project in Switzerland, called the Microbiota Vault, started in 2018. The researchers who founded it were inspired by the Svalbard Global Seed Vault, a "doomsday" seed depository in Norway that currently holds around 1.3 million plant samples to preserve genetic diversity as it dwindles in the real world.

Until now, the Microbiota Vault was in its "launch" phase, where it tested the feasibility of collecting and exporting poop and fermented foods from across the world, according to the commentary. Researchers in Switzerland have received a total of 1,204 fecal samples and 190 food samples from Benin, Brazil, Ethiopia, Ghana, Laos, Thailand and Switzerland over the past seven years, and these samples are currently stored at minus 112 degrees Fahrenheit (minus 80 degrees Celsius) at the University of Zurich.

The initiative is now in a "growth" phase, where researchers want to acquire thousands of additional samples, including microbes from threatened ecosystems, according to the commentary. Plans are also underway to find a permanent location for the vault, ideally in a country with a cold climate, such as Switzerland or Canada.

"Maybe 100 years from now, having saved these microbes could prevent a major disaster," Blaser said in the statement.

"It is our obligation to future generations to preserve this microbial diversity," the team added in the article.

Multiple sclerosis is a disease that results when the immune system mistakenly attacks the brain and spinal cord. It affects nearly one million people in the U.S. and over 2.8 million worldwide. While genetics play a role in the risk of developing multiple sclerosis, environmental factors such as diet, infectious disease and gut health are major contributors.

The environment plays a key role in determining who develops multiple sclerosis, and this is evident from twin studies. Among identical twins who share 100% of their genes, one twin has a roughly 25% chance of developing MS if the other twin has the disease. For fraternal twins who share 50% of their genes, this rate drops to around 2%.

Scientists have long suspected that gut bacteria may influence a person's risk of developing multiple sclerosis. But studies so far have had inconsistent findings.

To address these inconsistencies, my colleagues and I used what researchers call a bedside-to-bench-to-bedside approach: starting with samples from patients with multiple sclerosis, conducting lab experiments on these samples, then confirming our findings in patients.

In our newly published research, we found that the ratio of two bacteria in the gut can predict multiple sclerosis severity in patients, highlighting the importance of the microbiome and gut health in this disease.

Related: Twin study reveals signs of MS that might be detectable before symptoms

Bedside to bench

First, we analyzed the chemical and bacterial gut composition of patients with multiple sclerosis, confirming that they had gut inflammation and different types of gut bacteria compared with people without multiple sclerosis.

Specifically, we showed that a group of bacteria called Blautia was more common in multiple sclerosis patients, while Prevotella, a bacterial species consistently linked to a healthy gut, was found in lower amounts.

In a separate experiment in mice, we observed that the balance between two gut bacteria, Bifidobacterium and Akkermansia, was critical in distinguishing mice with or without multiple sclerosis-like disease. Mice with multiple sclerosis-like symptoms had increased levels of Akkermansia and decreased levels of Bifidobacterium in their stool or gut lining.

Bench to bedside

To explore this further, we treated mice with antibiotics to remove all their gut bacteria. Then, we gave either Blautia, which was higher in multiple sclerosis patients; Prevotella, which was more common in healthy patients; or a control bacteria, Phocaeicola, which is found in patients with and without multiple sclerosis. We found that mice with Blautia developed more gut inflammation and worse multiple sclerosis-like symptoms.

Even before symptoms appeared, these mice had low levels of Bifidobacterium and high levels of Akkermansia. This suggested that an imbalance between these two bacteria might not just be a sign of disease, but could actually predict how severe it will be.

We then examined whether this same imbalance appeared in people. We measured the ratio of Bifidobacterium adolescentis and Akkermansia muciniphila in samples from multiple sclerosis patients in Iowa and participants in a study spanning the U.S., Latin America and Europe.

Our findings were consistent: Patients with multiple sclerosis had a lower ratio of Bifidobacterium to Akkermansia. This imbalance was not only linked to having multiple sclerosis but also with worse disability, making it a stronger predictor of disease severity than any single type of bacteria alone.

How "good" bacteria can become harmful

One of the most interesting findings from our study was that normally beneficial bacteria can turn harmful in multiple sclerosis. Akkermansia is usually considered a helpful bacterium, but it became problematic in patients with multiple sclerosis.

A previous study in mice showed a similar pattern: Mice with severe disease had a lower Bifidobacterium-to-Akkermansia ratio. In that study, mice fed a diet rich in phytoestrogens — chemicals structurally similar to human estrogen that need to be broken down by bacteria for beneficial health effects — developed milder disease than those on a diet without phytoestrogens. Previously we have shown that people with multiple sclerosis lack gut bacteria that can metabolize phytoestrogen.

Although the precise mechanisms behind the link between the Bifidobacterium-to- Akkermansia ratio and multiple sclerosis is unknown, researchers have a theory. Both types of bacteria consume mucin, a substance that protects the gut lining. However, Bifidobacterium both eats and produces mucin, while Akkermansia only consumes it. When Bifidobacterium levels drop, such as during inflammation, Akkermansia overconsumes mucin and weakens the gut lining. This process can trigger more inflammation and potentially contribute to the progression of multiple sclerosis.

Our finding that the Bifidobacterium-to-Akkermansia ratio may be a key marker for multiple sclerosis severity could help improve diagnosis and treatment. It also highlights how losing beneficial gut bacteria can allow other gut bacteria to become harmful, though it is unclear whether changing levels of certain microbes can affect multiple sclerosis.

While more research can help clarify the link between the gut microbiome and multiple sclerosis, these findings offer a promising new direction for understanding and treating this disease.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

When you think of electric fields, you likely think of electricity — the stuff that makes modern life possible by powering everything from household appliances to cellphones. Researchers have been studying the principles of electricity since the 1600s. Benjamin Franklin, famous for his kite experiment, demonstrated that lightning was indeed electrical.

Electricity has also enabled major advances in biology. A technique called electrophoresis allows scientists to analyze the molecules of life — DNA and proteins — by separating them by their electrical charge. Electrophoresis is not only commonly taught in high school biology, but it's also a workhorse of many clinical and research laboratories, including mine.

I am a biomedical engineering professor who works with miniaturized electrophoretic systems. Together, my students and I develop portable versions of these devices that rapidly detect pathogens and help researchers fight against them.

What is electrophoresis?

Researchers discovered electrophoresis in the 19th century by applying an electric voltage to clay particles and observing how they migrated through a layer of sand. After further advances during the 20th century, electrophoresis became standard in laboratories.

To understand how electrophoresis works, we first need to explain electric fields. These are invisible forces that electrically charged particles, such as protons and electrons, exert on each other. A particle with a positive electrical charge, for example, would be attracted toward a particle with a negative charge. The law of "opposites attract" applies here. Molecules can also have a charge; whether it's more positive or negative depends on the types of atoms that make it up.

In electrophoresis, an electric field is generated between two electrodes connected to a power supply. One electrode has a positive charge and the other has a negative charge. They are positioned on opposite sides of a container filled with water and a little bit of salt, which can conduct electricity.

When charged molecules such as DNA and proteins are present in the water, the electrodes create a force field between them that pushes the charged particles toward the oppositely charged electrode. This process is called electrophoretic migration.

Related: New DNA-infused computer chip can perform calculations and make future AI models far more efficient

Researchers like electrophoresis because it is fast and flexible. Electrophoresis can help analyze distinct types of particles, from molecules to microbes. Further, electrophoresis can be carried out with materials such as paper, gels and thin tubes.

In 1972, physicist Stanislav Dukhin and his colleagues observed another type of electrophoretic migration called nonlinear electrophoresis that could separate particles not only by their electrical charge but also by their size and shape.

Electric fields and pathogens

Further advancements in electrophoresis have made it a useful tool to fight pathogens. In particular, the microfluidics revolution made possible the tiny laboratories that allow researchers to rapidly detect pathogens.

In 1999, researchers found that these tiny electrophoresis systems could also separate intact pathogens by differences in their electrical charge. They placed a mixture of several types of bacteria in a very thin glass capillary that was then exposed to an electric field. Some bacteria exited the device faster than others due to their distinct electrical charges, making it possible to separate the microbes by type. Measuring their migration speeds allowed scientists to identify each species of bacteria present in the sample through a process that took less than 20 minutes.

Microfluidics improved this process even further. Microfluidic devices are small enough to fit in the palm of your hand. Their miniature size allows them to perform analyses much faster than conventional laboratory equipment because particles don't need to travel that far through the device to be analyzed. This means the molecules or pathogens researchers are looking for are more easily detected and less likely to be lost during analysis.

For example, samples analyzed using conventional electrophoresis systems would need to travel through capillary tubes that are about 11 to 31 inches (30 to 80 centimeters) long. These can take 40 to 50 minutes to process and are not portable. In comparison, samples analyzed with tiny electrophoresis systems migrate through microchannels that are only 0.4 to 2 inches (1 to 5 centimeters) long. This translates to small, portable devices with analysis times of about two to three minutes.

Nonlinear electrophoresis has enabled more powerful devices by allowing researchers to separate and detect pathogens by their size and shape. My lab colleagues and I showed that combining nonlinear electrophoresis with microfluidics can not only separate distinct types of bacterial cells but also live and dead bacterial cells.

Tiny electrophoresis systems in medicine

Microfluidic electrophoresis has the potential to be useful across industries. Primarily, these small systems can replace conventional analysis methods with faster results, greater convenience and lower cost.

For example, when testing the efficacy of antibiotics, these tiny devices could help researchers quickly tell whether pathogens are dead after treatment. It could also help doctors decide which drug is most appropriate for a patient by quickly distinguishing between normal bacteria and antibiotic-resistant bacteria.

My lab is also working on developing microelectrophoresis systems for purifying bacteriophage viruses that can be used to treat bacterial infections.

With further development, the power of electric fields and microfluidics can speed up how researchers detect and fight pathogens.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

What happens to a dead body in an extremely cold environment? Does it decompose? How do these conditions affect how forensic scientists understand when the person died?

Estimating time of death, also called the post-mortem interval, is a complex task. It plays an important role in forensic investigations, as it can provide critical insights into the timeline of events leading up to a person's death. This information can narrow down potential scenarios and suspects, aiding in the resolution of criminal cases.

A multitude of factors are at play at a death scene, ranging from environmental conditions to the individual's health status prior to death. Historically, scientists have estimated time of death by observing post-mortem physical and biological changes in the body, such as stiffening, fluid collection and cooling.

These methods are limited, however, by their variability and dependence on external factors. Calculating the post-mortem interval became more precise with the advent of molecular biology. But it's still a challenging task, especially in extreme cold weather conditions. There is often a lack of obvious signs of decomposition on a frozen body during the first months after death.

We are forensic scientists leading the forensics programs at the University of North Dakota and the University of Central Lancashire. We use molecular biology and bioinformatics to develop tools to help researchers and investigators more accurately estimate the post-mortem interval. Our recently published research in Frontiers in Microbiology found that studying the microbes involved in decomposition could predict time elapsed since death in extreme cold conditions with high accuracy.

Decomposition in cold environments

Our study took place in Grand Forks, North Dakota, one of the coldest cities in the United States, where winters are characterized by temperatures that can drop to -40 degrees Fahrenheit (-40 degrees Celsius) and high winds that can reach up to 31 miles per hour (50 kilometers per hour).

In an extremely cold environment like North Dakota's winters, traditional methods might not be enough to understand decomposition and estimate time of death. For instance, the body cools much faster in cold conditions, which can skew estimates based on body temperature.

Related: Microbiome of death' uncovered on decomposing corpses could aid forensics

Similarly, cold environments can delay the onset and duration of rigor mortis, or body stiffening. The process of decomposition, including the activity of insects and other scavengers that contribute to the breakdown of the body, can also be slowed or halted by freezing temperatures.

Snow is another important factor when investigating decomposition. It can insulate a body by trapping residual heat and raising its temperature slightly higher than the surrounding environment. This insulating effect allows the body to decompose at a slower rate compared with bodies exposed to open air.

Microbes and time since death

In conditions of extreme cold, it becomes necessary to employ additional means to understand decomposition and estimate the time of death. Advanced molecular techniques, such as analyzing the microbiome, gene expression and protein degradation, can help provide valuable information about the crime scene.

Each organism has distinct microbial characteristics that act like a fingerprint. The necrobiome, a community of microbes associated with decomposing remains, plays a crucial role in decay. Specific microbes are present during different stages of decomposition, contributing to the breakdown of tissues and the recycling of nutrients. Forensic investigators can sample what microbes are living in a dead body to deduce how long ago a person died based on the makeup of the microbial population.

Our study focused on identifying common patterns in the microbial changes that occur during decomposition in extreme cold environments. Over a period of 23 weeks, we collected and analyzed 393 samples of microbes from the inside and outside of the noses dead pigs covered in snow. Pigs decompose similarly to humans and are commonly used in forensic research. We developed models to estimate the post-mortem interval by pairing microbial genetic data with environmental data such as snow depth and outdoor temperature.

Overall, we found that the bacterial species Psychrobacter, Pseudomonas and Carnobacterium may best predict time after death in extreme winter conditions up to six months after death, with a margin of error of just over nine days.

We found that different bacterial species are most abundant at different time intervals. For example, levels of Psychrobacter increase five weeks after death and are most abundant at 10 weeks, while Pseudomonas increase between five to nine weeks and hit a peak at 18 weeks.

Improving forensics

Death is often an unpleasant topic to bring into a conversation. But from a forensic perspective, having techniques and methods to determine when someone has died can help bring justice and peace for loved ones.

Our study found that decomposition does not completely halt even in cold environments. Studying the microenvironment — the local conditions surrounding the body, including temperature, humidity and microbial activity — can reveal crucial information about the decomposition process. The key microbial species we identified served as biomarkers of death, allowing us to develop time-of-death models that researchers can use to overcome the limitations of just visually examining remains.

Microbes can become a crucial piece of the puzzle during the process of investigating a death by aiding in constructing more precise timelines, even in extreme conditions.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

As humans alter the planet's climate and ecosystems, scientists are looking to Earth's history to help predict what may unfold from climate change. To this end, massive ice structures like glaciers serve as nature's freezers, archiving detailed records of past climates and ecosystems — including viruses.

We are a team of microbiologists and paleoclimatologists that studies ancient microorganisms, including viruses preserved within glacier ice. Along with our colleagues Lonnie Thompson, Virginia Rich and other researchers at the Ice Core Paleoclimatology group at The Ohio State University, we investigate interactions between viruses and their environment archived in ice cores from the Guliya Glacier on the Tibetan Plateau.

By linking the genomes of ancient viral communities to specific climate conditions preserved in glacier ice, our newly published research offers insights into how these viruses have adapted to Earth's shifting climate over the past 41,000 years.

Reading history in viral genes

We primarily used metagenomes — collections of genomes that capture the total genetic content of all microorganisms present in environmental samples — to reconstruct viral genomes from nine distinct time intervals within the Guliya ice core. These time horizons span three major cold-to-warm cycles, providing a unique opportunity to observe how viral communities have changed in response to different climatic conditions.

Through our analyses, we recovered the genomes of the equivalent of 1,705 virus species, expanding known glacier-preserved ancient viruses more than fiftyfold.

Only about one-fourth of the viral species we found shared species-level similarities with any of the viruses identified in nearly 1,000 metagenomes previously captured in global datasets. Most of these overlapping species were also from the Tibetan Plateau. This suggests that at least some viruses preserved in the Guliya Glacier originated locally in the region, but it also spoke to the relative lack of glacial viruses in available databases.

Using these new reference genomes, we attempted to "read" their stories.

Related: Some viruses have a mysterious 'Z' genome

One key finding was that viral communities varied significantly between cold and warm climatic periods. The most distinct community of viral species on the glacier appeared about 11,500 years ago, coinciding with the major transition from the Last Glacial Stage to the Holocene. This suggests that the unique climate conditions during cold and warm periods profoundly influenced the composition of viral communities. We hypothesize that these influences were likely due to viruses from other places being blown in by changing wind patterns and subject to selection pressures from changing temperatures on the glacier.

Digging deeper, we next determined how viruses interacted with their hosts. To do this, we used computer models to compare viral genomes with the genomes of other microbes also found in this environment. We found that viruses consistently infected Flavobacterium, a lineage of bacteria commonly found in glacier environments.

We also learned that viruses on the Guliya Glacier must "steal" genes from their hosts to manipulate their metabolisms. Encoded within the viral genomes were 50 auxiliary metabolic genes related to metabolism, including the synthesis and breakdown of vitamins, amino acids and carbohydrates. Some of these genes were abundant across all nine time intervals studied, suggesting that they help microbial hosts cope with the harsh conditions on glacier surfaces and thereby improve viral fitness.

Thus, viruses not only infect and kill cells, but they likely also alter the fitness of their hosts during infection, in turn influencing their capacity to survive in the extreme conditions of glacier environments.

Climate change over time

Our findings offer a novel perspective on how life, in the form of viruses, has responded to climatic changes over tens of thousands of years.

Understanding these ancient interactions provides a unique opportunity for future research in both virology and climate science. By studying how ancient viruses responded to past climate changes, researchers can gain valuable insights into how viruses adapt to ongoing global climate change.

We believe that glacier ice, by capturing information on microorganisms and their ecosystems over time in each layer, remains a critical resource for unraveling the history of Earth's climate and the life it has supported — especially as glacier ice reserves rapidly diminish.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

Most species of bacteria can be broadly divided into two groups, known as gram-positive and gram-negative. These categories reflect big differences in the microbes' biology, and they also dictate how doctors treat bacterial infections.

But what are the differences between gram-positive and gram-negative bacteria?

The names themselves date back to 1884, when Danish bacteriologist Hans Christian Gram developed a staining procedure to view bacteria under the microscope. First, he applied a dye, called gentian violet, which penetrates both the protective wall and membrane of bacteria, thus staining the material inside. Then, he added the mineral iodine, which formed a complex with the dye that wouldn't break down in water, thus "fixing" the stain in place.

After being washed with alcohol, some bacteria remained blue or purple, while others did not retain the stain. The first group was dubbed "gram-positive," while the latter was designated "gram-negative."

Related: Dangerous 'superbugs' are a growing threat, and antibiotics can't stop their rise. What can?

Gram's stain experiment pointed toward some sort of difference in the structures of various bacterial cells. However, it was not until the early 1950s that scientists started to understand the differences in the chemical composition of bacterial cell walls that makes a difference in the staining.

Differences between gram-positive and gram-negative bacteria

All bacteria have a cell wall composed of mesh-like strands of a big molecule called peptidoglycan, which surrounds the cell membrane. A cell wall provides the bacterial cell sturdiness and helps maintain its shape and internal pressure. However, there are some key differences between the two classes of bacteria.

First, gram-negative bacteria have a thin cell wall that is about 1.5 to 10 nanometers across, whereas gram-positive bacteria have a thick cell wall measuring about 20 to 80 nanometers.

Second, the cell walls of gram-negative bacteria are surrounded by an outer membrane that has different properties than the inner membrane encased by the wall. This outer membrane is involved in allowing nutrients into the cell and adhering to other, nearby cells, a function that plays a role in infections. Gram-positive bacteria, on the other hand, lack such an outer membrane.

Both classes of bacteria share strategies that they use to resist antibiotics, Mark Blaskovich, a professorial research fellow and group leader at the University of Queensland in Australia, told Live Science in an email. For example, structures called "efflux pumps" in the cell membrane allow bacterial cells to pump out antibiotics that get inside the cell.

Bacterial cells can also make enzymes that chemically inactivate antibiotics; these include beta-lactamase enzymes, which inactivate the class of antibiotics that includes penicillin. Bacterial cells can also alter the parts of their biology targeted by antibiotics, such as proteins or fats; this is equivalent to changing the lock so the key doesn't fit anymore, Blaskovich said.

Bacteria can also pick up antibiotic resistance from neighboring bacterial cells, even if they belong to a totally different species. That's because the microbes can swap small pieces of DNA that carry antibiotic-resistance genes from one bacterial cell to another. These genes can be traded through direct physical contact between the cells in a process called conjugation.

Related: Superbugs are on the rise. How can we prevent antibiotics from becoming obsolete?

All that said, when it comes to antibiotic resistance, gram-negative bacteria have an edge thanks to their double membranes.

The outer membrane of gram-negative bacteria physically blocks some large, water-hating (hydrophobic) antibiotic molecules, such as vancomycin and rifampicin. Because these treatments are blocked from entering the cell, this makes the microbes naturally resistant to the drugs, David Livermore, a professor of medical microbiology at the University of East Anglia in the U.K., told Live Science in an email.

Small, water-loving (hydrophilic) antibiotics can cross the outer membrane, but the membrane still slows down their entry. If a given bacterium has the ability to destroy or pump out the incoming antibiotic, "this is made much more efficient by restricting their rate of entry," Livermore said.

He compared the gram-negative bacterial cell to a castle with small gates in the wall. Because the enemies — antibiotic drugs — are coming in slowly, the defenders — bacteria's defense mechanisms — have an easier time dealing with them. If the battle were on an open field, the enemies would rush in all at once and the defenders would be quickly overwhelmed.

Because gram-negative bacteria are so good at fighting off antibiotics, they pose a particularly big threat to human health, according to the World Health Organization.

The extra outer membrane of gram-negative bacteria generally gives them an advantage over gram-positive bacteria when it comes to beating back antibiotics. However, certain existing drugs, such as polymyxins, and some new experimental drugs target this outer membrane by damaging it or by preventing its manufacture, Livermore said. Currently, these drugs are used as a last-resort treatment for gram-negative bacterial infections that are resistant to multiple antibiotics.

Ever wonder why some people build muscle more easily than others or why freckles come out in the sun? Send us your questions about how the human body works to community@livescience.com with the subject line "Health Desk Q," and you may see your question answered on the website!

A rich microbial "biosphere" lies buried 13 feet (4 meters) beneath the scorched surface of Chile's Atacama Desert, new research has found. The hidden world of bacteria is one of the deepest found in Atacama soils and could inform the search for life on Mars.

Microbial life has previously been recorded down to depths of 2.6 feet (80 centimeters) in the Atacama Desert, but the new biosphere, in the region's bone-dry Yungay Valley is "completely isolated from the surface," according to the researchers.

The newly discovered community inhabits soils between 6.6 feet (2 m) and at least 13 feet deep, according to a study, published Tuesday (April 23) in the journal PNAS Nexus. It is dominated by Actinobacteria, a diverse group of bacteria found in other extreme environments, including the Arctic, boiling hot springs and salty seas. 

"Little is known about microbial life in deeper sediment layers," researchers wrote in the study. "Communities described in this study could represent the upper extent of a deep biosphere underneath hyperarid desert soils."

The researchers also found Actinobacteria living closer to the surface, between 0.8 and 2 inches (2 to 5 cm) deep. Digging deeper, the team found bacteria belonging to the phylum Firmicutes, which are resilient to high concentrations of salt and do not require oxygen to survive, according to the study.

Related: Lost world of lagoons filled with mounds of microbes discovered in Atacama desert

The Atacama Desert is the driest hot desert in the world, receiving as much sunshine as Venus. While only a handful of animals survive the harsh conditions — including Darwin's leaf-eared mouse (Phyllotis darwini) and the South American gray fox (Lycalopex griseus) — some bacteria thrive in the desert's salty, mineral-rich soils. 

To find out more about these microscopic inhabitants, the researchers extracted soil samples from a pit in the Yungay Valley and extracted any DNA fragments they could find. Previous work has not differentiated between DNA from living and dead microbes, so the researchers designed a method to separate DNA still contained in living cells — known as intracellular DNA — from free-floating, or extracellular DNA.

"This approach provides a significant improvement for microbial diversity studies of extreme environments as it effectively eliminates bias from DNA derived from dead cells," they wrote in the study.

Bacteria were abundant in the top 2.6 feet of soil, but they were virtually absent between 2.6 and 6.6 feet deep, where salt concentrations were too high for even the sturdiest microbes. But at the lower depth, the researchers discovered a "transition zone" to a stable microbial community. This transition zone coincided with a change from clay-rich soils known as playa deposits to ancient river deposits.

The team suggests Actinobacteria colonized the river deposits around 19,000 ago and became buried beneath playa sediments over thousands of years. They also proposed that  the microbes survive at depth by extracting water from gypsum, which forms when the mineral anhydrite is exposed to water. This reaction is reversible at high temperatures, which could release water within Atacama soils.

The Atacama desert is often used as an analog for studying the harsh conditions of Mars, where the surface is completely lifeless, but may hide evidence of microbial life below. The new research could further inform the search for life on the Red Planet, as Mars also has gypsum deposits, which could potentially serve as a water source for extraterrestrial life, the researchers noted in the study.

"To our knowledge, this represents the deepest microbial survey and discovery of microbial life in Atacama soils to this day," they added.

In a groundbreaking discovery, scientists uncovered the first known structure in complex cells that's capable of drawing nitrogen from the atmosphere and converting it into a form that the cell can use.

They've dubbed the newfound cell part the "nitroplast." And according to two recent studies, the researchers think it likely evolved 100 million years ago.

The nitroplast probably developed from a bacterium in the ocean, after the microbe was engulfed by an algal cell. The bacteria and algae were previously thought to be living in symbiosis, with the microbe supplying nitrogen in a form the algae could use and the algae providing the microbe with a home.

But it turns out that the microbe took on a new form long ago, becoming a full-fledged cell structure, or organelle, with a metabolism directly linked to that of the algae.

Related: Does evolution ever go backward?

"It's very rare that organelles arise from these types of things," Tyler Coale, a postdoctoral scholar at the University of California, Santa Cruz (UCSC) and lead author of one of two recent studies that identified the nitroplast, said in a statement.

The discovery is only the fourth known example in Earth's history of "primary endosymbiosis," a process by which a eukaryotic cell — a cell where DNA is enclosed in a nucleus, as in all animals, plants and fungi — swallows a prokaryotic cell, which lacks a nucleus. In this case, a eukaryotic algal cell swallowed a prokaryotic bacterial cell.

"The first time we think it happened, it gave rise to all complex life," Coale said, referring to the evolution of mitochondria, the cells' powerhouses, approximately 1.5 billion years ago. "Everything more complicated than a bacterial cell owes its existence to that event." That includes humans.

The second known instance of endosymbiosis took place roughly 1 billion years ago, giving rise to chloroplasts, which power photosynthesis, and triggering the evolution of plants. The third known event may have given rise to a lesser-known organelle known as the chromatophore, a pigment-filled structure in the skin of cephalopods, such as squid and octopuses, that allows them to change color.

Scientists first discovered the microbe-turned-nitroplast in 1998, although at the time, they didn't yet know the microbe was a true organelle.

In that work, a team led by Jonathan Zehr, a distinguished professor of marine sciences at UCSC and lead author of the second recent study, recovered a short DNA sequence of the microbe from Pacific Ocean seawater. Zehr and his colleagues determined that the DNA belonged to a nitrogen-fixing cyanobacterium, which they called UCYN-A. (Nitrogen-fixing refers to the process of transforming nitrogen into a usable form for cells.)

The discovery coincided with work at Kochi University in Japan, where scientists figured out how to culture the algae that carry UCYN-A in the lab. This enabled Zehr and collaborators to compare the size of UCYN-A in different species of these algae, which belong to a related group called Braarudosphaera bigelowii.

The researchers published this work March 28 in the journal Cell, reporting that  the growth of UCYN-A and its host cells are synchronized and controlled by the exchange of nutrients. This is "exactly what happens with organelles," Zehr said in the statement. "If you look at the mitochondria and the chloroplast, it's the same thing: they scale with the cell."

To confirm these results, Zehr and additional researchers conducted a second study, which was published April 11 in the journal Science. Its results indicated that UCYN-A imports proteins from its host cell, suggesting that the former microbe had ditched some of its cellular machinery, relying instead on its host to function. In other words, the once-bacterium had become a cog in the machinery of its host.

"That's one of the hallmarks of something moving from an endosymbiont to an organelle," Zehr said. "They start throwing away pieces of DNA, and their genomes get smaller and smaller, and they start depending on the mother cell for those gene products — or the protein itself — to be transported into the cell."

UCYN-A also replicates at the same time as its host cell and is inherited like other organelles, sealing the discovery of the nitroplast, according to the statement.

A patchwork of crystal-clear lagoons and vast salt plains in Argentina's Puna de Atacama desert forms an otherworldly ecosystem unlike "anything any scientist has ever seen," researchers say.

The never-before-seen lagoons host mounds of rock layered with microbes that, at first glance, resemble some of the first known forms of life on Earth. Researchers discovered this lost world by chance after spotting a network of strange pools on satellite images of the desert in northwestern Argentina.

Puna de Atacama is a giant plateau more than 12,000 feet (3,660 meters) above sea level on the Argentinian border with Chile. There, high altitude, bone-dry conditions and blazing sunshine combine to form a harsh environment where few plants and animals survive.

Brian Hynek, an associate professor of geological sciences at the University of Colorado Boulder, and Maria Farías, a microbiologist and co-founder of the environmental consultancy PunaBio, hiked several miles through the barren landscape before they saw the lagoons.

Related: Trippy satellite map of North America's largest glacier shows off 'hidden lagoon' and other secrets

"It's unlike anything I've ever seen or, really, like anything any scientist has ever seen," Hynek said in a statement.

Twelve pools of shallow, crystalline water ringed with mountains make up the newfound alien ecosystem, which stretches across 25 acres (10 hectares) of desert, according to the statement. Beneath the lagoons' surface, the researchers spied small hills carpeted with green microbial growth. 

"It's just amazing that you can still find undocumented things like that on our planet," Hynek said, adding that the discovery constitutes "the biggest eureka moment I've ever had in my life."

The living mounds, which measured some 15 feet (4.6 m) across and several feet high, offer a window into the earliest stage of life on Earth and potentially even ancient life on Mars, Hynek said. Preliminary observations indicate they could be stromatolites — complex communities of microbes whose excretions solidify into layers of rock — similar to those that existed during a period of Earth's history called the Archaean (4 billion to 2.5 billion years ago), when the atmosphere contained no oxygen.

Stromatolites still form today in various marine and freshwater habitats, but they grow much smaller than their ancient counterparts. The mounds in the Atacama lagoons were close in size to Archaean stromatolites, which fossil discoveries indicate grew up to 20 feet (6 m) high. The Atacama stromatolites were mostly made of gypsum — a mineral common in fossilized stromatolites, but absent from modern examples. 

"We think these mounds are actually growing from the microbes, which is what was happening in the oldest ones," Hynek said. 

The hilly formations — soaked in the lagoons' salty, acidic waters and baked by extreme solar radiation — hosted two types of microbes, with layers of photosynthetic bacteria called cyanobacteria coating the outside, and communities of single-celled organisms known as archaea thriving at the core.

"If life ever evolved on Mars to the level of fossils, it would have been like this," Hynek said. "Understanding these modern communities on Earth could inform us about what we should look for as we search for similar features in the Martian rocks."

But researchers will have to act fast if they want to confirm these initial observations, as the site has been leased to mine for lithium.

"This entire, unique ecosystem could be gone in a matter of years," Hynek said. "We're hoping that we can protect some of these sites, or at least detail what's there before it's gone or disturbed forever."

Almost since antibiotics were first discovered, we've been aware bacteria can learn how to overcome these medicines, a phenomenon known as antimicrobial resistance.

The World Health Organization says we're currently losing to the bugs, with resistance increasing and too few new antibiotics in the pipeline.

We wanted to know whether experts around the world think we will still have effective antibiotics in 50 years. Seven out of seven experts said yes.

Related: Dangerous 'superbugs' are a growing threat, and antibiotics can't stop their rise. What can? 

A deeper understanding of the molecular aspects of bacterial resistance has led to the discovery of new treatment strategies, such as the inhibition of key enzymes that play a pivotal role in bugs becoming resistant. And advances in computer technology have greatly accelerated drug discovery and development efforts, offering hope for the rapid discovery of new antibiotics and treatment strategies.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

Each human body contains a complex community of trillions of microorganisms that are important for your health while you’re alive. These microbial symbionts help you digest food, produce essential vitamins, protect you from infection and serve many other critical functions. In turn, the microbes, which are mostly concentrated in your gut, get to live in a relatively stable, warm environment with a steady supply of food.

But what happens to these symbiotic allies after you die?

As an environmental microbiologist who studies the necrobiome — the microbes that live in, on and around a decomposing body — I've been curious about our postmortem microbial legacy. You might assume that your microbes die with you — once your body breaks down and your microbes are flushed into the environment, they won’t survive out in the real world.

In our recently published study, my research team and I share evidence that not only do your microbes continue to live on after you die, they actually play an important role in recycling your body so that new life can flourish.

Related: What is the vaginal microbiome?

Microbial life after death

When you die, your heart stops circulating the blood that has carried oxygen throughout your body. Cells deprived of oxygen start digesting themselves in a process called autolysis. Enzymes in those cells — which normally digest carbohydrates, proteins and fats for energy or growth in a controlled way — start to work on the membranes, proteins, DNA and other components that make up the cells.

The products of this cellular breakdown make excellent food for your symbiotic bacteria, and without your immune system to keep them in check and a steady supply of food from your digestive system, they turn to this new source of nutrition.

Gut bacteria, especially a class of microbes called Clostridia, spread through your organs and digest you from the inside out in a process called putrefaction. Without oxygen inside the body, your anaerobic bacteria rely on energy-producing processes that don’t require oxygen, such as fermentation. These create the distinctly odorous-gases signature to decomposition.

From an evolutionary standpoint, it makes sense that your microbes would have evolved ways to adapt to a dying body. Like rats on a sinking ship, your bacteria will soon have to abandon their host and survive out in the world long enough to find a new host to colonize. Taking advantage of the carbon and nutrients of your body allows them to increase their numbers. A bigger population means a higher probability that at least a few will survive out in the harsher environment and successfully find a new body.

A microbial invasion

If you're buried in the ground, your microbes are flushed into the soil along with a soup of decomposition fluids as your body breaks down. They're entering an entirely new environment and encountering a whole new microbial community in the soil.

The mixing or coalescence of two distinct microbial communities happens frequently in nature. Coalescence happens when the roots of two plants grow together, when wastewater is emptied into a river or even when two people kiss.

The outcome of mixing — which community dominates and which microbes are active — depends on several factors, such as how much environmental change the microbes experience and who was there first. Your microbes are adapted to the stable, warm environment inside your body where they receive a steady supply of food. In contrast, soil is a particularly harsh place to live – it's a highly variable environment with steep chemical and physical gradients and big swings in temperature, moisture and nutrients. Furthermore, soil already hosts an exceptionally diverse microbial community full of decomposers that are well adapted to that environment and would presumably outcompete any newcomers.

It's easy to assume that your microbes will die off once they are outside your body. However, my research team's previous studies have shown that the DNA signatures of host-associated microbes can be detected in the soil below a decomposing body, on the soil surface and in graves for months or years after the soft tissues of the body have decomposed. This raised the question of whether these microbes are still alive and active or if they are merely in a dormant state waiting for the next host.

Our newest study suggests that your microbes are not only living in the soil but also cooperating with native soil microbes to help decompose your body. In the lab, we showed that mixing soil and decomposition fluids filled with host-associated microbes increased decomposition rates beyond that of the soil communities alone.

We also found that host-associated microbes enhanced nitrogen cycling. Nitrogen is an essential nutrient for life, but most of the nitrogen on Earth is tied up as atmospheric gas that organisms can't use. Decomposers play a critical role recycling organic forms of nitrogen such as proteins into inorganic forms such as ammonium and nitrate that microbes and plants can use.

Our new findings suggest that our microbes are likely playing a part in this recycling process by converting large nitrogen-containing molecules like proteins and nucleic acids into ammonium. Nitrifying microbes in the soil can then convert the ammonium into nitrate.

Next generation of life

The recycling of nutrients from detritus, or nonliving organic matter, is a core process in all ecosystems. In terrestrial ecosystems, decomposition of dead animals, or carrion, fuels biodiversity and is an important link in food webs.

Living animals are a bottleneck for the carbon and nutrient cycles of an ecosystem. They slowly accumulate nutrients and carbon from large areas of the landscape throughout their lives then deposit it all at once in a small, localized spot when they die. One dead animal can support a whole pop-up food web of microbes, soil fauna and arthropods that make their living off carcasses.

Insect and animal scavengers help further redistribute nutrients in the ecosystem. Decomposer microbes convert the concentrated pools of nutrient-rich organic molecules from our bodies into smaller, more bioavailable forms that other organisms can use to support new life. It's not uncommon to see plant life flourishing near a decomposing animal, visible evidence that nutrients in bodies are being recycled back into the ecosystem.

That our own microbes play an important role in this cycle is one microscopic way we live on after death.

 This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

A large, snow-white ulcer swelled up on the dangly tissue at the back of a man's throat, but doctors couldn't immediately explain why. It turns out that a single-celled parasite was the culprit, and it had likely been hanging around the man's body for five years.

According to a new report of the case, published Thursday (Aug. 17) in the journal JAMA Otolaryngology–Head & Neck Surgery, the 62-year-old man initially went to the doctor about a sore throat. He had no recent travel history or contact with sick people, but the midline of his throat had been hurting for two weeks. An examination of his throat revealed bumps decorating the tissue, as well as sticky, yellow mucus and an ulcer on his uvula, the tissue that hangs in the back of the mouth.

An initial round of antibiotic and antifungal treatment didn't work, and the man's symptoms worsened over the following two weeks. Searching for the infection's cause, the doctors tested the patient for COVID-19; the viral disease mononucleosis, or "mono"; and group A Streptococcus, the bacteria behind strep throat. All of the tests came back negative. Then, they took a tissue sample from the man's throat. The sample was teeming with immune cells that usually help fight infections.

However, the cause of the infection remained elusive. To no avail, the doctors prescribed antibiotics, antifungals, heartburn medications and steroids that didn't relieve the man's symptoms.

Related: Cambrian fossils show oldest example of parasites in action

In the end, a deep dive into the man's medical history and closer examination of his ulcer biopsy would reveal the cause of his illness.

Five years prior, he'd traveled to Guyana, in South America, and subsequently sought medical treatment for multiple small lumps that had grown beneath the skin of his neck. At the same time, he also had a larger, 1.6-inch (4 centimeters) bump that indicated a deep infection of the skin. At that time, the man tested negative for disease-causing fungi and bacteria, and after antibiotics failed to treat the bumps, doctors surgically removed the largest nodules. The smaller ones resolved on their own.

However, years down the line, the mysterious ulcer appeared on the man's uvula, and doctors uncovered both its cause and the likely cause of the previous lumps: Leishmania braziliensis, a species of single-celled parasite that causes an infection called leishmaniasis.

Humans can contract L. braziliensis through the bites of infected sand flies, according to the Centers for Disease Control and Prevention (CDC). The parasites live in the tropics, subtropics and Southern Europe, and the CDC advises travelers to take measures to avoid sand fly bites while visiting affected locations.

The most common form of leishmaniasis, cutaneous leishmaniasis, causes skin sores that typically appear weeks or months after the initial fly bite or, more rarely, years later. The sores are often painless and usually heal on their own, but they can persist for months to years and leave scars. And with some Leishmania species, there's also a risk the parasite will spread elsewhere if left untreated in the skin.

In the man's case, he initially had cutaneous leishmaniasis, which caused the bumps on his neck. The infection then spread from his skin to the mucous membranes of his mouth and throat, causing what's known as mucosal leishmaniasis. The disease causes symptoms years to decades after a person's original cutaneous bumps, and when it occurs, it's typically if those first bumps went untreated or were treated ineffectively, the CDC notes.

The man's doctors analyzed a sample of his original skin bumps, collected five years earlier, and a stain revealed the parasites nestled inside his skin cells.

To finally kill the parasites, the doctors prescribed a month-long course of the leishmaniasis drug miltefosine. This treatment "led to complete resolution of the mucosal lesion and associated symptoms," the case report authors concluded.

A microscopic worm survived in the Siberian permafrost for a record-breaking 46,000 years, scientists have discovered — tens of thousands of years longer than previously resurrected worms.

The ancient roundworm, or nematode, belongs to the newly described species Panagrolaimus kolymaensis. Researchers discovered it nestled inside a fossilized squirrel burrow that was extracted from permafrost near the Kolyma River, in the northeastern Arctic, in 2002. Scientists resuscitated the frozen nematode in 2018, but its age and species remained unclear.

Now, a study published Thursday (July 27) in the journal PLOS Genetics may have found answers to these questions. "Survival in extreme environments for prolonged periods is a challenge that only a few organisms are capable of," researchers wrote in the study. "Here, we show that a soil nematode Panagrolaimus kolymaensis suspended life for 46,000 years in the Siberian permafrost."

Organisms such as nematodes and tardigrades can enter a dormant state — a metabolic process known as "cryptobiosis" — in response to being frozen or extremely dehydrated, intermediary states known as cryobiosis and anhydrobiosis, respectively. In both cases, the critters reduce their oxygen consumption and the amount of heat produced by metabolic processes to undetectable levels.

Related: 'Prehistoric' mummified bear discovered in Siberian permafrost isn't what we thought 

The newly described nematode entered cryptobiosis in the late Pleistocene (2.6 million to 11,700 years ago), an epoch that included that last ice age. The permafrost that imprisoned the tiny creature had not thawed since then, meaning this is the longest recorded cryptobiosis in nematodes — by tens of thousands of years — according to the study. Until now, the Antarctic nematode species Plectus murrayi and a Tylenchus polyhypnus specimen held this record; the former was frozen in moss for 25.5 years and the latter was desiccated in a herbarium for 39 years.

The researchers analyzed the newly described nematode's genes and compared them to those of Caenorhabditis elegans roundworms, which were the first multicellular organisms to have their entire genome sequenced. In the absence of established genetic methods to study the recently thawed worm, C. elegans provided a well-studied model organism for comparison. The analysis revealed several shared genes linked to cryptobiosis.

To find out exactly how nematodes can survive for such long periods, the researchers got a new group of P. kolymaensis and C. elegans worms and mildly desiccated them in the lab. As the worms entered anhydrobiosis, the team observed a spike in the production of a sugar called trehalose, which they think could help protect the nematodes' cell membranes from dehydration. They then froze the worms at minus 112 degrees Fahrenheit (minus 80 degrees Celsius) and found that desiccation improved the survival rates of both species. Worms that were frozen at this temperature without being dehydrated beforehand died instantly, according to the study. 

Equipped with molecular pathways to cope with Arctic conditions, nematodes have evolved to survive in these hibernating states for many thousands of years, the researchers concluded. "Our findings indicate that by adapting to survive [in a] cryptobiotic state for short time frames in environments like permafrost, some nematode species gained the potential for individual worms to remain in the state for geological timeframes," they wrote in the study.

This means that extinct nematode species could be revived if they escape from the permafrost, the researchers noted. "Drastic changes" to the environment in which they lay dormant, including fluctuations in temperature and natural radioactivity, can wake ancient nematodes from their deep slumber, they added. 

Locked away in frigid Arctic soils and riverbeds is a world teeming with ancient microbes. Bacteria and viruses that existed thousands of years ago are frozen in time inside prehistoric layers of permafrost.

Warming temperatures could cause much of the ice to melt and unleash these microbes from their frosty prisons. Once free, unknown pathogens could infect humans or other animals.

"The risk is bound to increase in the context of global warming, in which permafrost thawing will keep accelerating, and more people will populate the Arctic,” Jean-Michel Claverie, a computational biologist at Aix-Marseille University in France who studies ancient and exotic viruses, told CNN.

So far, scientists have only studied permafrost viruses that infect single-celled organisms called amoebas, because these viruses are harmless and provide a good model for others that may be lurking under the ice.

"We will never risk isolating a virus eventually capable of infecting modern mammals," Claverie told Live Science in an email. "We do not have formal proof that viruses other than amoeba-specific viruses could survive as long, but there would be no reason why not, because all viruses basically have the same property of being inert particles while outside their host cells. We do not wish to take the immense risk of starting a new pandemic with unknown 'zombie' viruses from the distant past just to demonstrate that we are right." 

From pathogens resurrected from clumps of mammoth wool to particles hiding in the petrified intestines of a Siberian wolf, here are eight viruses that scientists have pulled from the permafrost.

Related: The deadliest viruses in history 

 1. Pithovirus sibericum 

Pithovirus sibericum is one of the biggest viruses ever found. At about 1.5 micrometers long, it's about the size of a small bacterium and belongs to a group known as "giant viruses," which are double-stranded DNA viruses that are (with some exceptions) visible under a light microscope. P. sibericum looks like a thick-walled oval with an opening at one end and is capped by a cork structure and a honeycomb-like grid.

Scientists hunting for unknown pathogens discovered P. sibericum nestled deep inside a core of ancient Siberian permafrost that was extracted in 2000 from Kolyma, in the Russian Far East. They resurrected the 30,000-year-old virus by exposing a permafrost sample to amoebas, which are the only known P. sibericum hosts. (The virus is harmless to humans and other animals.)

"Our protocol is to put amoeba cultures (in the lab) in contact with various samples, in the hope that they will contain viruses capable of infecting amoebas," Claverie said. 

The researchers named the virus after the Greek word "pithos," which refers to large containers, or amphoras, used by the ancient Greeks to store wine and food. They published their results in a 2014 study in the journal PNAS. 

2. Mollivirus sibericum

Mollivirus sibericum was found frozen in the same 30,000-year-old Siberian permafrost sample as P. sibericum. M. sibericum particles are smaller than those of P. sibericum (0.6 to 1.5 micrometers in length) — but they, too, are visible under a light microscope and qualify as giant viruses. The roughly spherical virus is surrounded by a hairy protective layer and can produce and release 200 to 300 new viral particles from each amoeba it infects.

Although M. sibericum poses no danger to humans and other animals, the discovery of two ancient viruses in a single sample suggests that dormant pathogens may often lurk in permafrost, researchers cautioned in a 2015 study published in the journal PNAS.

"We cannot rule out that distant viruses of ancient Siberian human (or animal) populations could reemerge as arctic permafrost layers melt and/or are disrupted by industrial activities," they wrote in the study.

3. Pithovirus mammoth

Pithovirus mammoth is the second strain of Pithovirus on record and was isolated from a clump of 27,000-year-old, petrified mammoth wool unearthed on the banks of the Yana River in the Russian Far East. P. mammoth has a large and elongated particle that measures 1.8 micrometers in length and displays a similar cork-like structure as P. sibericum. Amoebas are its only host.

Claverie and his colleagues described P. mammoth in a study published earlier this year. That research identified 13 "zombie" viruses revived from Siberian permafrost, three of which — P. mammoth, Megavirus mammoth and Pandoravirus mammoth — were discovered in the same prehistoric sample containing mammoth wool. 

4. Pandoravirus mammoth

P. mammoth is a strain of the Pandoraviridae family of viruses, which constitute the vast majority of viruses revived from permafrost. Pandoraviruses are amoeba-infecting, giant viruses that have large, amphora-shaped particles measuring up to 1.2 micrometers in length.

Researchers discovered P. mammoth in the 27,000-year-old frozen sample of mammoth wool from the Yana riverbank and in the 28,600-year-old, petrified content of a mammoth's stomach in the Lyakhovsky Islands off the coast of northeastern Russia.

The team exposed the newfound Pandoravirus strain to a culture of amoebas, as well as to human and mouse cells, which is the standard protocol to verify that viruses cannot infect mammalian cells. 

5. Pandoravirus yedoma

Pandoravirus yedoma is the oldest virus resurrected from permafrost to date. Researchers discovered the 48,500-year-old, amoeba-infecting pathogen in icy deposits under a lake in Yukechi Alas, in the Russian Far East. P. yedoma is one of the 13 "zombie" viruses described in the study published Feb. 18 in the journal Viruses and has a large, egg-shaped particle that measures 1 micrometer in length.

Researchers date viruses locked in permafrost using radiocarbon, which is a radioactive type of carbon that decays at a known rate and can help determine the age of organic materials. In samples older than 50,000 years, however, the remaining amount of radioactive carbon is so small that current techniques cannot accurately date the material. 

6. Megavirus mammoth

Megavirus mammoth is the first virus discovered in permafrost that belongs to the Mimiviridae family.

Mimiviruses were the first viruses that researchers classified as giant viruses, after discovering them in the water of a cooling tower in Bradford, England, in 1992. Mimiviruses infect amoebas and have particles that are 0.5 micrometer in diameter and enclosed in a capsule with 20 identical, triangular facets. Megaviruses, such as M. mammoth, belong to a subfamily of Mimiviridae and have the same characteristics.

Researchers isolated the newfound strain from a 27,000-year-old clump of ice and mammoth wool discovered on the Yana riverbank, together with P. mammoth and P. mammoth. 

7. Pacmanvirus lupus

Pacmanviruses are a recently discovered group of amoeba-infecting viruses that are distantly related to the African swine fever virus of the Asfarviridae family. Scientists named them after the video game "Pac-Man" because, when broken, the protein shell looks like a gaping mouth.

Pacmanvirus lupus is the third recorded member of this group and the first strain isolated from permafrost — specifically, from the 27,000-year-old frozen intestinal remains of a Siberian wolf (Canis lupus). Scientists described the newly thawed virus, which they unearthed at the Yana site, in the study published earlier this year.

Pacmanviruses are classified as giant viruses, but the newfound strain is only 0.2 micrometer in length and invisible under a light microscope.

8. Cedratvirus lena

Cedratviruses are amoeba-infecting giant viruses that belong to a subgroup of the Pithovirus family, which includes P. sibericum and P mammoth. Scientists isolated three previously unknown strains of Cedratvirus at different locations in the Russian Far East and described them in the study published earlier this year.

Researchers extracted Cedratvirus lena from permafrost on the muddy banks of the Lena River in the Russian Far East. The newfound strain has an elongated particle measuring 1.5 micrometers in length that resembles that of P. sibericum, but it has two cork-like structures at each end instead of one.

The team harvested two other Cedratvirus strains in the Russian Far East: C. kamchatka, from frozen soil on the Kamchatka Peninsula, and C. duvanny, from mud flowing into the Kolyma River as a result of thawing permafrost of mixed ages. 

Scientists have discovered never-before-seen viruses that thrive in sunlit oceans from pole to pole and infect plankton. They dubbed the newfound microbes "mirusviruses" — "mirus" meaning "strange" in Latin.

The researchers concluded that mirusviruses belong to a large group of viruses called Duplodnaviria, which includes the herpesviruses that infect animals and humans, based on shared genes that encode the shell, or "particle" enclosing their DNA. But the strange, newfound viruses also share a staggering number of genes with a group of giant viruses, called Varidnaviria.

This suggests that mirusviruses are a bizarre hybrid between two distantly related viral lineages, the scientists concluded.

"They seem to be an extremely unusual group of viruses," Tom Delmont, a researcher at the French National Centre for Scientific Research (CNRS) who participated in the discovery, told Live Science. "This is why we consider them as being chimeric, because they are a mix of two different groups of viruses — on one side the herpesviruses, based on the particle genes, and on the other side the giant viruses, based on many more genes."

The team described the strange, newfound viruses in a study published Wednesday (April 19) in the journal Nature. The discovery highlights how little we know about the viruses lurking in Earth's oceans.

Related: Scientists discover viruses that secretly rule the world's oceans

To find the viruses, the team pored over data from the Tara Ocean expedition, which collected nearly 35,000 ocean water samples containing viruses, algae and plankton between 2009 and 2013. The researchers then searched for evolutionary clues in millions of microbes' genes.

"Working on this data is like surveying a huge area of sand with a metal detector, looking for a treasure," Delmont said. "We found an evolutionary treasure."

In combing through this data trove, the scientists detected a previously undescribed lineage of double-stranded DNA viruses, the mirusviruses, that can be found in the sunlit surface waters of polar, temperate and tropical oceans. These abundant viruses infect plankton, which are tiny organisms that drift on ocean currents and can produce spectacular blooms visible from space, according to the National Ocean Service. 

By invading the plankton's cells, mirusviruses likely help regulate the microorganisms' activity and thus the flow of carbon and nutrients through the ocean.

"Viruses are a very natural component of plankton at the surface of the ocean," Delmont said. "They are going to destroy many, many cells every day and this is going to release nutrients, particles inside the cells that are going to be used by other cells to be active and healthy."

Mirusviruses may be the key to resolving the enigmatic origin of herpes viruses, Delmont said. The genes encoding the protective shell around viral DNA are strikingly similar in both groups, suggesting that they are related.

"This means that there is a shared evolutionary history between herpes, that infect only animals, and the mirusviruses that are everywhere in the ocean, where they infect unicellular organisms," Delmont said. "All of this is pointing to a planktonic origin for herpes."

These unusual viruses represent a new front for research into microbial life in our oceans and there are many more discoveries in store, Delmont said.

"We will be trying to isolate mirusviruses in the coming year," co-author Hiroyuki Ogata, a professor at the Institute for Chemical Research at Kyoto University, told Live Science in an email. "Isolation is now essential to uncover the mystery of this new viral [group]."

There is a frozen soup of viruses, bacteria and fungal spores lurking beneath the frigid Arctic soil. Unlike the icy leftovers in the back of your freezer, some of these microbes haven't interacted with a cell since well before ancient Egyptians built the Pyramids of Giza about 4,500 years ago. As climate change continues to cook the planet, however, these permafrost-locked germs are beginning to thaw. 

But can newly defrosted microbes "wake up" and infect anything? And how much of a potential threat do they pose to human and environmental health? Those are the questions an international team of scientists began to probe in a new study, published online Feb. 18 in the journal Viruses.

Disease outbreaks from permafrost are not unprecedented. Siberian reindeer herds periodically contract anthrax from bacteria in melted permafrost, according to research published in 2021 in the journal Frontiers in Veterinary Science, and the issue has affected a handful of humans in these regions as well.

For the new study, which has not been peer-reviewed, the researchers isolated 13 newly described viruses from seven permafrost samples and two water samples taken from Siberian rivers. Three of the viruses — named Megavirus mammoth, Pithovirus mammoth and Pandoravirus mammoth — were found inside 27,000-year-old petrified mammoth wool. Another was discovered in the frozen intestines of an ancient Siberian wolf. 

Related: The deadliest viruses in history

In a contained lab setting, the scientists carefully thawed the microbes and sequenced their genomes. Then, the researchers infected amoeba cells with the newly awakened viruses. Despite being up to 48,000 years old, several of the viruses were able to replicate within the amoebas, causing them to burst open and release fresh viral particles.

"The ones we revived are no danger at all; they only infect amoeba," Jean-Michel Claverie, a computational microbiologist at Aix-Marseille University in France and co-author of the new study, told Live Science in an email. "But their presence and infectivity suggests that ancient viruses infecting animals/humans could still be infectious."

The researchers focused on amoeba-infecting viruses because amoebas make good model organisms and because there would be minimal risk of accidental spillover to lab technicians. "We are using [the amoeba's] billion years of evolutionary distance with humans and other mammals as the best possible protection," they wrote in the paper. 

Previous studies of viruses locked within Arctic permafrost have been few and far between. However, the authors said this study disproves an older hypothesis that permafrost contains few viable microbes; in addition to the viruses they revived, the team found trace evidence of numerous other species, including some related to known human pathogens, such as poxviruses and herpesviruses. 

But if one of these strains did awaken and infect humans, modern vaccines likely would offer some protection. The biggest risk, according to the authors, is from unknown viruses. Like SARS-CoV-2, the pathogen responsible for COVID-19, these germs have the potential to spread rapidly through a population that lacks natural immunity, triggering a pandemic. Such a virus would need to be studied and understood even as it infected people, making vaccine development tricky. 

As of now, political upheaval in the region has halted the collection of new permafrost samples. "Because of the Russia-Ukraine war, all our collaborations are stopped now," Claverie explained, adding that his lab will continue to study the viruses they have. And they hope that companies setting up drilling and mining operations on the Siberian permafrost take heed and proceed with caution — for example, by monitoring for unusual diseases and setting up appropriate quarantine facilities.

"We believe the point is made that viruses of any kind can survive in permafrost," Claverie said.

Editor's note: Originally published on Dec. 6, 2022 and updated at 11:33 a.m. EST on March 10, 2023 to note that the study, which was previously posted on the preprint database bioRxiv, had been published on Feb. 18, 2023 in Virus, a peer-reviewed journal. 

What looks like a kaleidoscope of glowing ice cream sprinkles or a cross between a nebula and a 1980s dance party is actually something even more astonishing: an unfettered and detailed view of the exact locations of DNA and RNA inside a living cell.

The method that opened the doors for this unprecedented look inside living cells — known as DNA microscopy — was perfected over a period of six years, according to a new study.

"DNA microscopy is an entirely new way of visualizing cells that captures both spatial and genetic information simultaneously from a single specimen," study lead researcher Joshua Weinstein, a postdoctoral associate at the Broad Institute of MIT, said in a statement. [Check Out These Amazing Super-Detailed Images of Fruit Fly Brains]

The technique even allows researchers to see the exact order of nucleotides, the "letters" that make up DNA's double helix and RNA's single strand, within each cell.

"It will allow us to see how genetically unique cells — those comprising the immune system, cancer or the gut, for instance — interact with one another and give rise to complex multicellular life," Weinstein said.

Over the past few decades, researchers have developed myriad tools that help them collect molecular data from tissue samples. But efforts to pair this technology with spatial data — so that researchers know where and how genetic material inside a cell is arranged — often involves expensive and specialized machinery.

The new approach makes the process much easier, the researchers said. In essence, the method uses tiny tags — made out of customized DNA sequences each about 30 nucleotides long — that latch onto every DNA and RNA molecule in a cell. Then, the tags are replicated until there are hundreds of copies of them within the cell. As these copies interact with one another, they combine and make unique DNA labels, the researchers said.

The interactions between these DNA tags is key. Once researchers collect the labeled biomolecules and sequence them, they can use a computer algorithm to decode and reconstruct the tags' original positions in the cell, creating a color-coded virtual image of the sample. Pinpointing the location of each molecule is similar to how cellphone towers triangulate the locations of nearby cellphones, the researchers said.

The technique may help researchers better understand different kinds of human disease. For instance, in the study the researchers showed that DNA microscopy could map the locations of individual human cancer cells in a sample. These synthetic DNA tags can even help scientists map the locations of antibodies, receptors and molecules on tumor cells, they said.

"We've used DNA in a way that's mathematically similar to photons in light microscopy," Weinstein said. "This allows us to visualize biology as cells see it and not as the human eye does."

The study was published online yesterday (June 20) in the journal Cell.

• Tiny & Nasty: Images of Things That Make Us Sick
• Images: Human Parasites Under the Microscope
• Photos: Amazing Microscopic Views of Italian Cocktails

Originally published on Live Science.

Chile's Atacama Desert, the driest nonpolar desert on Earth, stretches across a roughly 600-mile (1,000 kilometers) tract of land wedged between the coastal Cordillera de la Costa mountain range and the Andes Mountains. The region boasts stunning geologic formations and has provided scientists with a wealth of research opportunities.

Old, hot and dry

The Atacama is the oldest desert on Earth and has experienced semiarid conditions for roughly the past 150 million years, according to a paper in the November 2018 issue of Nature. Scientists estimate that the desert's inner core has been hyperarid for roughly 15 million years, thanks to a combination of unique geologic and atmospheric conditions in the area. This perfectly parched inner-desert region spans roughly 50,000 square miles (130,000 square km), according to soil scientist Ronald Amundson of the University of California, Berkeley.

The Atacama is tucked in the shadow of the snow-capped Andes Mountains, which block rainfall from the east. To the west, the upwelling of cold water from deep in the Pacific Ocean promotes atmospheric conditions that hamper the evaporation of seawater and prevent the formation of clouds and rain. [Photos: The Haunting Splendor of Chile's Atacama Desert]

In other deserts around the world, like the Sahara, the mercury can soar above 130 degrees Fahrenheit (50 degrees Celsius). But temperatures in the Atacama are comparatively mild throughout the year. The average temperature in the desert is about 63 degrees F (18 degrees C).

An analogue for other worlds

The outskirts of the Atacama are home to communities of organisms that have adapted to thrive in harsh conditions. The desert's hyperarid core, however, is largely devoid of plant and animal life, save for a few strains of microbial life. Scientists hope that studying the dry, dusty conditions of the Atacama will reveal secrets about the key to life in other parts of the universe, such as Mars.

"It's not the biology that makes scientists eager to study in the Atacama Desert — it's the lack of biology," said Henry Sun, an astrobiologist at the Desert Research Institute in Las Vegas, Nevada. Researchers suspect that the microbes that inhabit the desert's hyperarid core — which slip into a sort of stasis during periods of aridity — could survive life on the Red Planet.

"It's a really interesting place to see how tenacious life is on Earth and what the climatic limits to life as we know it really are," said Amundson. 

But even the most tenacious of life-forms can be disrupted.

On average, the driest part of the Atacama receives less than a millimeter of rain each year. In rare cases, torrents of rain do fall, and life responds. In 2017, wildflowers bloomed the aftermath of a dramatic downpour. Similar rainstorms were reported in March and August of 2015.

Although the rains awakened fields of wildflowers, the floods had devastating consequences for microbial life in the desert, which has adapted to survive without water. Many microbes in the desert's hyperarid core, for instance, burst after absorbing too much rainwater.

Scientists suspect that these catastrophic storms may become more frequent as the climate changes and atmospheric conditions in the Pacific Ocean fluctuate. "Instead of making the desert drier, climate change could actually make it wetter," said Amundson.

Geologic wonderland

Much of the Atacama Desert's core is caked in thick salt deposits called playas, which can stretch for miles and are nearly half a meter thick (1.6 feet) in some places. The desert is speckled with stones that have been carried across the playas by powerful wind gusts. Alluvial fans, which are large, fan-shaped sediment deposits, connect the desert plateau with the mountains that surround it and suggest that water once flowed from the Andes into the desert.

The Atacama also features a 435-mile-long (700 km) and 12-mile-wide (20 km) swath of desert known as the nitrate belt. Nitrate minerals can be found in everything from explosives to fertilizer and were mined extensively in the Atacama before the 1930s.

Traditionally scraped from the desert's crusty surface or mined from rocky veins, nitrates were initially thought to be carried to the desert by wind-swept sea spray. Recently, scientists discovered that one of the sources for the desert's "white gold" might be ancient, evaporated groundwater.

Other materials, such as lithium, copper and iodine, have also been mined nearby; in some cases, the remnants of these mining operations can be seen from space.

A dazzling array of telescopes

At 16,570 feet (5,050 meters) in elevation, the Atacama Desert plateau may be the best place in the world to spot the solar system's secrets. To the delight of amateur astronomers, the desert sees as many as 330 cloud-free nights each year. High along the Atacama Desert plateau, an array of observatories track the celestial bodies in our solar system and beyond.

The Atacama Large Millimeter Array/submillimeter (ALMA) — a network of 66 telescopes run by an international collaboration of scientific organizations from Europe, North America, East Asia and the Republic of Chile — spies on faraway stars and the planets birthed around them.

The European Space Observatory's Very Large Telescope, helped spot the TRAPPIST-1 system of Earth-like planets, located a mere 40 light-years from Earth, and has gathered data on distant exoplanet atmospheres. This telescope, along with others, has uncovered some of the universe's most intriguing oddities and provided a wealth of data to researchers and astronomers worldwide.

Additional resources:

• Southern Night Sky Revealed: Chile's Atacama Desert (Photos)
• 8 Cool Facts About the ALMA Telescope
• Explore the Atacama, from the Medical University of South Carolina.

It's that time of the year again: when the weather is warm, and people are swarming the beach. That means it's also the time of year when doctors see a sharp rise in a certain type of "flesh-eating" bacterial infections called vibriosis.

These infections are caused by Vibrio bacteria, which thrive in warm, coastal seawater and often infect widely consumed shellfish species, like oysters. Scientists warn that as climate change causes an increase in sea surface temperatures and a rise in sea levels, Vibrio infections will become more common. This is because warmer, rising waters create an even more welcoming evironment for the deadly pathogen.

There are more than 70 species of Vibrio, with 12 of them recognized as human pathogens, according to the Centers for Disease Control and Prevention (CDC). But only two of those 12 are responsible for the majority of infections in beachgoers and raw-shellfish consumers: V. vulnificus and V.  parahaemolyticus. [5 Ways Climate Change Will affect Your Health]

"V. vulnificus is the one that causes the highest number of [deaths] and is often associated with wound infections," said Kimberly Reece, a marine microbiologist at the Virginia Institute of Marine Science. V. vulnificus is often called flesh-eating bacteria because when it infects a wound, it causes the skin and surrounding tissue to gruesomely break down and die. (Medically, this is called necrotizing fasciitis.) 

V.  parahaemolyticus, on the other hand, is the species more often found in shellfish, and although it causes more vibriosis cases, it's not as deadly as V. vulnificus, Reece said. Typically, people who get vibriosis from shellfish may experience such symptoms as gastrointestinal discomfort (diarrhea and vomiting), but if they're otherwise healthy, they will generally recover within a few days.

However, the infection is hardest on people with compromised immune systems or pre-existing diseases. People with an already weakened immune system can become seriously ill and die from both types of Vibrio infections. According to the CDC, vibriosis kills about 1 in 4 people who contract it, sometimes within only one or two days.  

Thriving in the heat

The CDC says that 80 percent of Vibrio infections occur between May and October, when coastal water is warmest. But as coastal water temperatures increase globally, so are cases of Vibrio infections.

"We're seeing more of these infections early on in the season and later in the season," said Craig Baker-Austin, a marine microbiologist at the Centre for Environment Fisheries and Aquaculture Science in the United Kingdom.

Vibrio is one of the only pathogens with increasing rates of illness in the U.S. Between 1996 and 2005, the average incidence of vibriosis in the southeastern U.S. increased by more than 80 percent, according to a recent study in the journal Estuaries and Coasts.

The same study described a clear relationship between increased Vibrio concentrations in waters off the southeast coast of the U.S., and increased salinity and temperature. But the researchers found that sea level rise is likely to have the biggest influence on increased rates of infections. That's because Vibrio thrives in brackish water, or water that's just slightly salty, such as marshes, estuaries and other coastal regions. As the sea level rises, the ocean's salt water will penetrate farther into freshwater rivers and streams, creating more habitat for Vibrio.

Baker-Austin told Live Science that with climate change, "we're also seeing more extreme weather events, and those can play a big role" in Vibrio proliferation. For example, he said, after Hurricane Katrina in 2005, there was a lot of salt water and fresh water mixed together, and people were wading through it. Because of that, Baker-Austin said, there was a marked increase in vibriosis cases in the region.

Higher latitudes are also experiencing warmer coastal temperatures, which means the geographical range of Vibrio is likely to expand. "I think the most important thing is to recognize that with climate change, you might start to see Vibrio infections in regions where you haven't seen [them] before," Reece told Live Science.

Education is key

Even though the rate of Vibrio infections is increasing, said Baker-Austin, "it's worth highlighting that they're very rare infections." In 2017, the CDC estimated that, in the U.S., about 80,000 people become infected by Vibrio bacteria each year, and about 100 people die from the infection. For reference, about 400 times more people were infected with the influenza virus in U.S. than were infected with Vibrio bacteria.

Still, both microbiologists told Live Science that it's important to stay vigilant about the risks of vibriosis.

"Seawater is teeming with bacteria and viruses and all sorts of things," Baker-Austin said. People with any kind of open wound, cut or abrasion have a "portal of entry" for the bacteria, he said, so they need to minimize their exposure to seawater.

"People have to be aware of their own health," Reece said. For example, she said, people who are taking certain medications or have compromised immune systems should make sure their shellfish are thoroughly cooked, which kills the potentially harmful bacteria.

Reece also noted that the shellfish industry is working hard to prevent infection by keeping the shellfish at lower temperatures that prevent the bacteria from multiplying. "They're doing a very good job, and they recognize that's really important," she said.

But as Baker-Austin said, "There's more people living by the sea, more people coming into contact with seawater and more people with underlying risk conditions." Those factors, together with the overall trend of warming seawater and rising seas, mean these heat-loving bacteria are likely to continue to cause more and more vibriosis cases every year. But understanding the risks of infection and taking the appropriate steps to avoid those risks can prevent infection and save your life.

Original article on Live Science.

What do Vincent van Gogh's painting "The Starry Night," a map of New York City and a countryside harvest landscape have in common? Perhaps not much, but all of these images can be re-created by growing colorful microbes in petri dishes — and they were for this year's Agar Art Contest, an unusual annual competition sponsored by the American Society for Microbiology.

For the contest, creative microbiologists were encouraged to submit a piece of art using bacterial or yeast colonies as paint, and agar (a gelatinous substance used to grow cultures) as a canvas. There were 85 entries in total, and the winning creations were recently on September 29.

First place went to Mehmet Berkmen of New England Biolabs, who worked with artist Maria Penil to create piece called "Neurons." The petri dish was painted to look like nerve cells using the yellow-tinged bacteria called Nesterenkonia and the orange-colored bacteria called Deinococcus and Sphingomonas. [In Photos: The Microbe Masterpieces of the 2015 Agar Art Competition]

To keep the contents of their petri dishes looking artistic, Berkmen and Penil allowed bacteria to grow inside the dish for a few days at a stable temperature, but then they sealed the masterpiece with epoxy, cutting off the oxygen that aerobic bacteria need to grow, and preserving the artwork.

The second place winners made a "microbial map" of New York City. The art was made by Christine Marizzi, a community educator who worked with citizen scientists and artists at Genspace: New York City's Community Biolab, using a harmless strand of Escherichia coli bacteria. These microbes were tinted with proteins, giving the map its colorful appearance.

A more pastoral landscape also grabbed judges' attention, and the third place slot in the contest. The "Harvest Season" piece features the green, yellow and red hues of Saccharomyces cerevisiae, a species of yeast. The autumnal entry, which depicts a farmhouse surrounded by wheat fields, was submitted by Maria Eugenia Inda, a postdoctoral researcher from Argentina who works at Cold Spring Harbor Labs in New York.

Other notable entries to the contest included the work of Melanie Sullivan, a microbiologist in Missouri, who submitted a striking copy of Van Gogh's masterpiece "The Starry Night." Nicola Fawcett of England used gut bacteria to create her aptly named entry "The Wild Garden of the Gut Bacteria" (which sounds much more disgusting than it looks).

You can take a look at all of the Agar Art Contest entries on the American Society for Microbiology's Facebook page.

Follow Elizabeth Palermo @techEpalermo. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.

If you don't think bacteria are beautiful, think again. This year's Agar Art Contest, an annual competition hosted by the American Society for Microbiology, is the source of some true microbe masterpieces. For the contest, microbiologists and artists "paint" strands of bacteria on agar, a gelatinous substance used to make biological cultures. Here are some of the winners and crowd favorites from the strange competition: [Read the full story about the Agar Art Contest]

Brainy bacteria

The first place prize in the contest went to Mehmet Berkmen of New England Biolabs and artist Maria Penil, who used yellow and orange-colored bacteria to paint the nerve cells they painted in their submission, called "Neurons." (Credit: American Society for Microbiology/Mehmet Berkmen and Maria Penil from Massachusetts.)

Microbial map

Christine Marizzi submitted this intricate map of New York City, and the interesting composition earned her second place. A community educator, Marizzi worked with citizen scientists and artists at Genspace: New York City's Community Biolab to create this street map of the Big Apple. (Credit: American Society for Microbiology/Christine Marizzi and Genspace: New York City's Community Biolab.)

Ode to autumn

Third place went to Maria Eugenia Inda, a postdoctoral researcher at Cold Spring Harbor Labs in New York, who created this petri dish masterpiece, "Harvest Season," using yeast. The bacteria-laden painting features a tiny farmhouse surrounding by wheat fields. (Credit: American Society for Microbiology/Maria Eugenia Inda from Argentina.)

People's Choice

This entry from Berkmen and Penil (the same duo that won first place in the competition) took home the "Viewers' Choice" award. (Credit: American Society for Microbiology/Mehmet Berkmen and Maria Penil from Massachusetts.)

Probiotic painting

These blossoming flowers are the work of researchers from IPLA-CSIC, a dairy research institute in Spain. The bacteria used to paint the blossoms is a popular probiotic, Bifidobacterium animalis subsp. lactis. (Credit: American Society for Microbiology.)

Botanical sun

This piece, entitled "Flowering Sunshine," was submitted by Manal Hamed of Qatar. (Credit: American Society for Microbiology/Manal Hamed of Qatar.)

Secret garden

This entry, titled "The Wild Garden of the Gut Bacteria," was submitted by Nicola Fawcett of the University of Oxford. Fawcett said she was inspired to create this swirling floral piece by the veritable "garden" of bacteria that lives, you guessed it, in the human gut. (Credit: American Society for Microbiology/by Nicola Fawcett of England.)

Microbe master

Just when you thought Vincent van Gogh's "The Starry Night" couldn't get any more beautiful, someone goes and recreates this masterpiece out of bacteria. Melanie Sullivan, a researcher at the Washington University School of Medicine, painted these petri dishes using a variety of bacteria, including one — Acinetobacter baumanii — that can be harmful to people with weakened immune systems. (Credit: American Society for Microbiology/Melanie Sullivan of Missouri.)

Viral artwork

Submitted by Paul Rowley of the University of Colorado, Boulder, this geometrically themed piece shows virus particles. The shapes were painted using a strain of yeast called S. cerevisiae, which was infected with a virus called L-A. (Credit: American Society for Microbiology/Paul Rowley of Colorado.)

Follow Elizabeth Palermo @techEpalermo. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science..

(ISNS) – Outbreaks of foodborne diseases carried by bacteria can be a nuisance at best, and deadly at worst. Researchers are looking into novel ways to keep food safe. One way to destroy these pathogens is with more pathogens.

Bacteriophages are viruses that specifically attack bacteria. These phages, as researchers call them, have evolved alongside bacteria and become very good at what they do.

Scientists are most interested in lytic phages – viruses that inject their DNA into a bacterium and then hijack the cell’s machinery to make new copies of the virus. The copies eventually burst through bacterium’s membrane, killing it, and attack neighboring cells.

Recently, a team of researchers at Purdue University in West Lafayette, Indiana developed a cocktail of different phages that was extremely effective against Escherichia coli O157:H7, the pathogen that was estimated to have caused more than 63,000 illnesses and 2,138 hospitalizations between 2000 and 2008 in the U.S.

The researchers mixed a cocktail of three phages and added it to ground beef or sprayed it on spinach. They found that the combination eliminated over 99% of E. coli O157:H7 on spinach stored at room temperature. They obtained similar results in refrigerated and room temperature beef.

These results, published online earlier this year in the Journal of Animal Science, are exciting but hardly new. Phage bio-control products are already available commercially.

One product, called ListShield, sold by Intralytix, controls Listeria monocytogenes and can be applied directly to poultry meat.

“It’s not widely used today. It’s gaining acceptance and sales are steadily increasing, but slowly,” said Alexander Sulakvelidze, vice president of research and development, and chief scientist of Intralytix.

“It’s a microorganism – the concept of putting a virus on foods is initially hard to swallow, if you will,” Sulakvelidze said.

But phages are harmless to humans; they only target bacteria. It’s highly unlikely that they will ever evolve to cause diseases for humans or animals. The bacteria, on the other hand, are highly virulent.

“[Phages] are not human pathogens. The bacteria are the human pathogens,” said Paul Ebner, a professor of animal sciences at Purdue and the lead author of the E. coli study.

Sulakvelidze added that phage bio-control products are an alternative to chemical washes and irradiation – two mechanisms commonly used to kill bacteria in ready-to-eat food products. Phages are much more specific – usually one phage targets only one species of bacteria. They kill the pathogenic “bad” bacteria while leaving the naturally occurring, “good” bacteria intact, making a more nutritious product.

Researchers are also looking into ways to treat bacterial infections in livestock using phages, but Sulakvelidze said that results from these tests are inconclusive so far. However, if phages prove successful in this way, it would greatly reduce the need for antibiotics in livestock and potentially eliminate the need to treat food products with phages.

Naturally, there is also a push to find a use for phages in humans. Antibiotic resistance in bacteria is a crisis. According to the Centers for Disease Control and Prevention, “each year in the United States, at least two million people become infected with bacteria that are resistant to antibiotics and at least 23,000 people die each year as a direct result of these infections.”

Phages are a hopeful alternative. “Phage therapy was the big thing in the [19]20s and 30s,” said Jason Gill, a microbiologist at Texas A&M University in College Station, who was not involved in the study.

Since then, researchers have struggled to get consistent results with phages. After penicillin hit the market in the early 1940s, phage therapy was largely abandoned.  But now that many bacteria are resistant to one or more antibiotics, phages are making a comeback.

Bacteria can become resistant to phages, as well. But one type of bacteria usually only develops resistance to one or two types of phages, which is why researchers use a cocktail. The probability that one type of bacteria can become resistant to multiple phages at once is extremely low, according to both Gill and Ebner.

But numerous obstacles obstruct the path to phage therapy in humans in the U.S. Regulations make phages difficult to patent. It's also relatively easy to find a similar phage in nature, said Gill.

Given those economic concerns, getting to clinical trials for human treatment takes millions of dollars that many drug companies aren’t willing to invest.

Ebner said that such worries are premature, because scientists don't know how the results from the lab will carry over to complex environments such as a pig's digestive system.

“So let’s go back a little bit and try to find which ones have the broader spectrum or grow the fastest or [destroy] the bacteria the fastest,” said Ebner.

Hope still abounds for phages, though.

“They’re the most abundant organism you can find in nature. We’re just harnessing that antibacterial process,” Ebner said.

Inside Science News Service is supported by the American Institute of Physics. Cynthia McKelvey is a science writer based in Santa Cruz, California. She tweets @NotesofRanvier.

(ISNS) -- A new map drawn by a team of biophysicists could point the way to better antibiotics. Rather than chart Earth’s geography, the scientists mapped how fast bacteria with different genetic mutations reproduce and how they respond to varying doses of a drug.

Such a map could help drugmakers develop treatments that block bacteria’s ability to evolve antibiotic resistance, said Terence Hwa, a biological physicist at the University of California, San Diego and a member of the research team. “If you’re going to attack somebody you want to have a map so you can plan out routes of attack.”

Antibiotic resistance is a growing public health threat in the U.S. and around the world. Drug-resistant bacteria sicken two million people and kill at least 23,000 each year in the U.S. alone, according to a 2013 Centers for Disease Control and Prevention report; far more die from such infections in other parts of the world. Researchers at pharmaceutical companies struggle to develop new antibiotics that can control resistant strains of Staph, tuberculosis and other pathogens.

When designing such drugs, researchers typically target wild bacterial populations. The resultant antibiotics often work until a small number of cells in an infected human or animal acquire a genetic mutation that enables them to survive and reproduce even when dosed with the drug. Over time, the mutated cells multiply while others die out. Eventually, the entire infecting population becomes resistant. If these cells then escape into the environment and infect other people or animals, the antibiotic can eventually become largely useless against a disease.

To better understand how such resistance evolves, a team led by Hwa and his former student Barrett Deris -- now a postdoctoral researcher at MIT -- studied how the antibiotic chloramphenicol affects the bacteria E. coli’s reproduction rate. The drug works by shutting down non-resistant cells’ protein factories. Because cells need proteins to survive, they respond by devoting more energy to repairing the factories and less to reproducing. At the same time, the cells begin building proteins that pump the drug out of the cell.

Deris wrote equations to describe how fast each of these processes occurs for different concentrations of drugs, and for different levels of the gene that codes for the antibiotic-removing pump. Graphing the solutions to these equations, he obtained a three-dimensional map resembling the mesa-studded landscape of the American desert Southwest, with a plateau giving way to a steep slope that levels out in a low-lying plain. The plateau represents combinations of drug levels and bacterial genes that allowed cells to reproduce and microbial populations to grow. The plain represents combinations that prevented cells from reproducing.

As antibiotic levels increased from zero, non-resistant bacteria quickly fell from the plateau to the plain. But the scientists discovered that cells with certain mutations in their DNA were able to build more pumps, clear the antibiotic faster and devote more energy to reproduction. These cells stayed on the plateau until the drug reached a higher concentration, after which they fell off abruptly; this indicated they had acquired partial resistance to the antibiotic. With enough beneficial mutations, bacteria became fully resistant and remained on the plateau no matter how much of a drug bath they received.

“This map is first of its kind in its ability to predict the growth rates of drug-resistant bacteria from first principles,” Deris said earlier this month at an American Physical Society meeting in Denver. He and his colleagues tested different strains of E. coli and antibiotics similar to chloramphenicol, and found the resulting maps all took the same basic shape.

The study “gives insight into a very, very important problem that’s affecting humans,” said Michael Reddy, a program director at the National Institute of General Medical Sciences in Bethesda, Md., which partially funded the research. And because cancer cells can evolve resistance to chemotherapy in the same ways bacteria evade antibiotics, he said the results could also lead to new cancer treatments.

But Reddy notes that further research is needed to confirm whether similar maps can be made for other classes of microbes and drugs. Deris said he hopes others will use his work to do such studies.

Inside Science News Service is supported by the American Institute of Physics. Gabriel Popkin (@gabrielpopkin) is a freelance science and environmental writer based in the Washington, D.C. area. He has written for Science News, ScienceNOW, Johns Hopkins Magazine and other publications.

Tiny marine organisms that are thought to play a crucial role in the planet's carbon and nutrient cycles are mysteriously shedding massive amounts of bacterial "buds," loaded with proteins and genetic information, into the world's oceans, according to a new study.

These so-called vesicles are spherical pouches containing DNA, carbon and nutrients that are being continually produced and released by Prochlorococcus, the most abundant type of cyanobacteria, which are miniscule photosynthesizing cells in the ocean that convert sunlight and carbon dioxide into oxygen and organic carbon. This puzzling discovery, reported online today (Jan. 9) in the journal Science, could lead to a new understanding of how carbon moves through the oceans, and possibly how genetic information is swapped between marine organisms, the researchers said.

Prochlorococcus is dominant in all of the world's open oceans, except at high latitudes, where the water is very cold, said Steve Biller, a postdoctoral researcher at MIT in Cambridge, Mass., and lead author of the new study. The oxygen exhaled by these photosynthesizing microbes helps nourish other organisms in the marine environment. [Extreme Life on Earth: 8 Bizarre Creatures]

"They're doing roughly 10 percent of all photosynthesis on the planet, so they play an important role at the base of the food web of the world's oceans," Biller told LiveScience.

The marine ecosystem

Biller began studying this type of cyanobacteria at MIT after a previous graduate student in his lab examined Prochlorococcus under a powerful electron microscope and was baffled by the presence of small, pimple-type specks around the cells.

"It was complete serendipity," said study co-author Sallie Chisholm, a professor of biology at MIT. "Anytime anyone new joined the lab, I would say, 'What do you think these are?' When Steve joined, he had classical training in microbiology, and thought they might be vesicles."

Other types of bacteria, such as E. coli, were previously known to produce vesicles, but this is the first time photosynthetic cells in the ocean have been shown to produce such extracellular structures, Chisholm said.

The vesicles were detected in laboratory cultures of cyanobacteria, and in samples of seawater taken from the nutrient-rich waters off the coast of New England and the more nutrient-sparse waters of the Sargasso Sea, a region in the middle of the North Atlantic Ocean.

The vesicles from the seawater were found to contain DNA from different types of bacteria — a discovery that suggests many other ocean microbes also may be capable of producing vesicles, Biller said. Furthermore, the researchers found that vesicles were being produced rapidly.

"We show that two to five vesicles are produced per cell per generation," Chisholm said. "This means that every time the cell divides into two, it produces two to five of these things. If you extrapolate that to global production, based on the growth rates of Prochlorococcus in the wild, it's a huge amount that they're shedding and putting out into the seawater." [50 Amazing Facts About Earth]

Biller estimates Prochlorococcus alone is releasing about a billion-billon-billion (a billion times a billion times a billion) vesicles per day, representing huge pools of carbon in the open oceans. Typically, bacteria grow to a certain size and then reproduce by dividing into two or more parts — a biological process known as fission. Under suitable conditions, bacteria can divide rapidly, with some populations capable of doubling in less than 10 minutes.

"It adds a whole other dimension to parts of the ocean that we need to better understand," Biller said. "For one, figuring out how carbon moves through the ocean has been something of a black box for a number of years. The idea that this could be a new mechanism for how some portion of that carbon moves around is pretty important."

An ocean of mysteries

Yet the discovery raises as many questions as it answers, he added. Most puzzling is why cyanobacteria would produce vesicles in the first place.

"If you have an organism eking out a living in a really dilute environment, where nutrients are extremely low, why would it cast things off into the environment that would limit its own growth?" Chisholm said. "We figure these vesicles have to have some important function."

Research in this area is preliminary, but the scientists have some intriguing hypotheses. For example, since the vesicles contain DNA, they could play a role in transferring genes and developing genetic diversity among populations of cyanobacteria in the oceans.

"They could be moving genetic information between cells in the ocean," Biller said. "We've also talked a little about their potential roles in helping to move nutrients around within the microbial food web. But the magnitude of these benefits to the cell is still beyond our understanding."

Other ideas include the production of vesicles as a defense mechanism against predators. Viruses have been shown to attach themselves to vesicles, injecting their DNA into the spherical structures. This effectively prevents the virus from being able to reproduce in a living cell.

As such, cyanobacteria could be deploying vesicles to use as decoys to deflect attacking viruses, said David Scanlan, a professor of marine microbiology at the University of Warwick in the United Kingdom. Scanlan, who was not involved in the new study, penned an accompanying editorial in the journal Science about the implications of the findings.

"It would be like thinking of these vesicles as anti-aircraft chaffs that planes use as decoys against missiles," Scanlan told LiveScience.

Moving forward

Yet, it is still unclear how these vesicles are produced and, in particular, how they come to contain genetic information, which is found in a cell's nuclei and mitochondria.

"If these vesicles are just budding off the outside of the cell, it's not really clear how DNA gets into them," Scanlan said. "It could be an interesting, and potentially novel, angle on how DNA and RNA can be moved between organisms."

In cells, RNA is a single-stranded molecule involved in the coding, regulation and expression of genes. Among its myriad functions, RNA works as an on-and-off switch for some genes.

Biller and his colleagues plan to investigate some of these ideas, but studying such tiny organisms remains challenging.

"It took about three years to get to this point, and it could take another five years to figure out why Prochlorococcus might be doing this," Chisholm said.

Follow Denise Chow on Twitter @denisechow. Follow LiveScience @livescience, Facebook & Google+. Original article on LiveScience.

(ISNS) – For over a century cranberries have been more than a Thanksgiving staple; they've also been heralded for their reported ability to prevent and even treat urinary tract infections.

But clinical research attempting to link cranberry consumption to a reduction in urinary tract infections remains somewhat inconsistent. A 2012 study by a team from Taiwan and the U.S., published in the Archives of Internal Medicine, found that consuming cranberries did seem to prevent urinary tract infections in certain populations, but qualified the findings with a strong word of caution against using the "folk remedy" as a treatment. 

Most research on the cranberry's effect on infections focuses primarily on its ability to prevent bacteria from attaching to a host cell. If the bacteria can't stick to bladder cells, they can't cause infections. But, in recent years, researchers at McGill University in Montreal have uncovered a new weapon that cranberries have against bacteria.

Bacteria on the move

A key factor in a bacterium's ability to infect a host cell is its motility, or how well it can move around. For some types of bacteria, their motility depends in part on their whip-like appendages known as flagella. The flagella allow the bacteria to swim around and, in some cases, actually swarm. The more bacteria can move, the more virulent they can become. This is especially the case in bacteria that cause urinary tract infections.

"Motility is actually a really important factor in infection," said Nathalie Tufenkji, a chemical engineer at McGill University. "It helps the bacteria spread up the urinary tract. It helps them also infect the cells."

Tufenkji and her colleagues were interested in discovering what the compounds in cranberries did to certain bacteria's gene expression.

They took E. coli that had been isolated from the urinary tract and exposed it to different concentrations of cranberry powder. They saw that when the cranberry powder was present, the E. coli's ability to swim and swarm dramatically decreased.

"When they swim and they swarm, what they are using? Well, they're using the flagella. So we said, OK, it must be affecting somehow the flagellum," explained Tufenkji.

Then, Tufenkji looked at how exposure to the cranberry influences bacteria's gene expression, specifically the way the flagella are constructed.

Bacteria that were grown in the presence of cranberries did not produce as many of the genes needed to construct flagella. Without functional flagella, the bacteria's motility was significantly hindered.

This research was published in the October 2011 issue of Applied and Environmental Microbiology.

Cranberry meets Proteus mirabilis

After observing E. coli's impaired motility after exposure to cranberries, Tufenkji tested the cranberry's effect on another bacteria common to urinary tract infections: Proteus mirabilis. This study was published in the June 2013 issue of the Canadian Journal of Microbiology.

"Proteus is this really aggressive swarmer," commented Tufenkji, which makes it particularly virulent in the urinary tract, especially in catheterized patients who already have a high risk of infection.

When patients are catheterized, any bacterium present on the catheter can easily swim or swarm its way up the urinary tract to infect bladder cells.

When the Proteus bacteria were exposed to high concentrations of cranberry powder, the researchers saw two interesting effects. First, just as in E. coli, the bacteria's ability to swim or swarm across an agar plate embedded with cranberry powder was almost completely eliminated.

Second, cranberry powder also appeared to disrupt the bacteria's production of the urease accessory gene, which affects how virulent the bacteria can become.

"This work is very interesting," said Terri A. Camesano, a chemical engineer at Worcester Polytechnic Institute in Massachusetts. "A lot of the other research is focusing on surface activity [of bacteria] and there's relatively less…on motility and how cranberry products affect certain gene expressions associated with flagellum motility."

An alternative to antibiotics

The two studies show that cranberry powder is able to essentially disable bacteria, but it does not kill the bacteria, "and that is key," said Tufenkji.

When antibiotics are used to treat infections, most bacteria are killed, but in the process any survivors can become resistant to the antibiotic used against them. The more often antibiotics are used, the more resistant the bacteria can become, resulting in dangerous strains of antibiotic-resistant bacteria.

Because cranberry powder only disables bacteria, the bacteria are not given the chance to grow stronger as they resist antibiotic intervention. Eventually, the disabled bacteria are simply flushed out of the body. As yet, it is unclear if the bacteria would eventually develop a resistance to the immobilizing effects of the cranberry, but researchers do know that the bacteria does not mutate in response to the cranberry powder.

 Cranberry-laced catheters

The concentrations of cranberry powder that were effective in disabling E. coli and Proteus were higher than what would typically be found in a human body, even if a person were intentionally drinking several glasses of cranberry juice daily to prevent or treat a urinary tract infection. So it is difficult to say that ingesting high volumes of cranberries would have any effect on bacterial motility.

In future research, however, Tufenkji plans to examine the effects of embedding cranberry powder into catheters themselves.

"The more people study cranberries the more we realize that there are clearly multiple different mechanisms going on by which cranberry compounds interact with bacteria that affects their potential to cause infection," said Camesano.

This story was provided by Inside Science News Service. Sara Suchy is a News Editor and Web Content Manager for Inside Science.

What might appear to some as Superman's secret icy sanctuary, the "Fortress of Solitude," is actually a microphotograph of sulfosalicylic acid crystal formation.

Thomas Balla of Fort Collins, Colo., captured this image magnified 200 times using polarized light, which is a contrast-enhancing technique.

Sulfosalicylic acid, also called salicylsulfonic acid, is a chemical used in medicine in tests for protein in urine and cerebrospinal fluid. A protein urine test measures the amount of protein, such as albumin, in a sample and is often used as a test for kidney disease. Normally, urine shouldn't have much protein as the kidneys reabsorb the material back into the bloodstream.

The chemical works by causing dissolved proteins, which can't all be seen by the naked eye, to solidify. These are then measured by the turbidity, or cloudiness of the fluid.

The stunning photo received an honorable mention at Nikon's 2013 Small World microphotography competition.

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What looks like a vivid, prickly broom is actually an adhesive pad on a foreleg of Coccinella septempunctata, or ladybird beetle (also called a ladybug). Dr. Jan Michels of the Christian-Albrechts-Universität zu Kiel in Germany, captured the image of the beetle's foreleg at 20x magnification using autofluorescence and the optical imaging technique confocal microscopy. ("The key to the confocal approach is the use of spatial filtering to eliminate out-of-focus light or flare in specimens that are thicker than the plane of focus," according to the Nikon microscopy website.)

These beetles have distinctive spots and bright coloring to make them unappealing to predators. The coloring reminds possible threats that ladybird beetles would taste awful if preyed upon. Creatures not deterred by the ladybird's coloring will taste a foul fluid secreted by its leg.

The photo was among the winners at Nikon's 2013 Small World microphotography competition, where it placed seventh.

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This 400x-magnified image is a very colorful close-up look at a microbiological water park of sorts created by the fungus Emericella nidulans. Fungi with filaments, like this one, produce a thin layer of protein called hydrophobin on their spherical spores. This protein sheet ensures water rolls off the spores, creating tiny slip 'n slides.

Hydrophobin is a cysteine-rich protein, an amino acid that can be formed in humans. Emericella nidulans has been used in research for more than 50 years, including in studies of recombination, DNA repair, mutation and cell cycle control.

Other types of fungi, like mushrooms, also have a layer of hydrophobin. While this image may look colorful, the fungi normally appears green to the naked eye.

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This ScienceLives article was provided to LiveScience in partnership with the National Science Foundation.

MIT environmental engineer Roman Stocker studies the interactions between the tiniest marine organisms, their fluid dynamical environment and their food sources. That work has conveyed understandings that shed light on global environmental processes.

A 2009 study of the micrometer-sized photosynthetic marine organisms called phytoplankton showed that the coupling of these cells' swimming behavior and ocean currents leads to the formation of intense layers of these creatures — which could be precursors of toxic algal blooms. Another study from Stocker's research group found that marine microorganisms are strongly attracted to sulfur compounds — the chemicals that give the sea its characteristic smell — and that this behavior could affect the chemical properties of the ocean and potentially influence global climate by altering cloud formation. 

Most recently, Stocker showed that ocean turbulence directly affects the ability of marine bacteria to recycle organic material back into the food web, a process that can alter species composition and ecosystem productivity. Stocker's work at the interface of fluid mechanics and microbial ecology has also led to insights in other fields: by discovering that the chirality of bacterial flagella leads to drift relative to flow, a 2009 study from his group revealed a new method for separating "right-handed" from "left-handed" molecules that could have broad applications in chemical engineering. Stocker's most widely known research was inspired by his cat Cutta Cutta.

Watching him one day over breakfast, he began to think about just what is going on when a cat laps milk. High-speed videos showed that a cat's tidy lapping of water or milk is governed by the competition between liquid inertia and gravity. The news appeared everywhere from the front page of the New York Times to Le Monde to Jay Leno's opening bit.

An associate professor in the department of civil and environmental engineering at MIT, Stocker is a winder of the Maseeh Award for Excellence in Teaching. He received his Ph.D. in environmental engineering from the University of Padua. Below, he answers our 10 questions.

Name: Roman Stocker Age: 37 Institution: MIT Field of Study: Fluid Mechanics and Microbial Ecology

What inspired you to choose this field of study?

It's really two fields! I got into fluid mechanics because I was fascinated by how water moves: the aesthetics of it, the mechanics of it, and its powerful consequences. Only later I realized that one of the coolest things in water is … life! And some of the most amazing, most diverse, and most important life forms are microbes. So now I work at the interface of fluid mechanics and microbial ecology.

What is the best piece of advice you ever received?

'Be positive' (from my dad). He actually said it a bit differently — he said "Unless there is a strong reason not to, why not smile?" — but 'be positive' is what this meant for me. Certainly 'positive' can be a character trait, but I believe it is a trait one can strongly influence. I think about those words from 30 years ago pretty often … and they still successfully make me smile every time!

What was your first scientific experiment as a child?

Trying to dam up little mountain creeks during summertime hikes, so as to build small pools in which to wade and splash. I found it intriguing how the water passed around, underneath and above the different materials I put in its way and this drove me to 'engineer' new obstacles, new components of my dam. Of course, it was a never-ending quest, for the water always found a way, but I now see that this was part of the fun!

What is your favorite thing about being a researcher?

Exploration. Which comes from freedom. Interrogating nature about its secrets, whether on a discovery trip or by peeking through a microscope. Doing it without constraints, primarily for the sake of understanding. And doing it in a team, where brainstorming sessions can become like detective work and the understanding one more of nature's secrets is a team victory.

What is the most important characteristic a researcher must demonstrate in order to be an effective researcher?

Creativity. Many other qualities are important: persistence, technical skill, logic. But I believe creativity — finding just the right experiment, asking just the right question, drawing just the right connection — is the most valuable quality, and the one I find myself continuously longing for.

What are the societal benefits of your research?

Understanding the environment, and particularly the ocean, so that we as humans can prevent impacting it and, ultimately, hurting ourselves.

Who has had the most influence on your thinking as a researcher?

It's not a single person, it's a specific period in my education. I'm Italian and in Italy you can choose high schools with different areas of focus. I attended a humanistic gymnasium. It was a detour, for my strengths were more quantitative and eventually I studied engineering in college, but it was a most valuable detour, as it provided me with a background in literature, philosophy, ancient history, and a passion for writing and languages that — unexpectedly I must say — I have come to consider key strengths in my current work as a researcher. The ability to write a clear and broadly appealing scientific paper, craft a compelling grant proposal, prepare an intriguing lecture, all contain major components that go beyond the technical knowledge.

What about your field or being a researcher do you think would surprise people the most?

About my field: how "alive" the ocean is, even at its smallest scales. Go to the beach, scoop up a handful of water, ask how many microbes live in it. Few suspect that the answer numbers in the millions and how important those millions of microcritters are.

About being a researcher: how much persistence and rigor are needed. Some of our studies have taken 4+ years and have resulted in a 4-page paper. A year per page??

If you could only rescue one thing from your burning office or lab, what would it be?

I would actually not worry too much. There are certainly some personal things — family pictures, a couple of drawings — that I am attached to, and others that it would take time and money to replace — all the equipment, some custom-made tools. But, ultimately, the most valuable resource is what we know and how we think: fortunately, those are not very flammable!

What music do you play most often in your lab or car?

Italian songwriters ('cantautori'), in particular from 10-15 years ago. De Gregori is my favorite, but also Zucchero, Jovanotti, Dalla ... probably exotic-sounding names to a non-Italian reader! They've always had, for me, the right balance of poetry, tune and simplicity: a good balance to strive for!

Editor's Note:This research was supported by the National Science Foundation, the federal agency charged with funding basic research and education across all fields of science and engineering. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author and do not necessarily reflect the views of the National Science Foundation. See the ScienceLives archive.

When deprived of other food sources, a widespread type of green algae can break down other plant materials and slurp them up as food, a new study finds.

It's the first time that a member of the plant kingdom has been shown to break down another plant's cellulose, the biopolymer that gives strength to plants' cell walls, and use it as an energy source, according to the new research.

Normally, the algae Chlamydomonas reinhardtii uses the sun to turn carbon dioxide and water into the simple sugar glucose, via the process of photosynthesis. But when researchers deprived the tiny cell of carbon dioxide, it cannibalized other plants' materials, said Lutz Wobbe, a researcher at Germany's University of Bielefeld and co-author of the study describing the finding, published recently in the journal Nature Communications.

"Our study for the first time demonstrates that an organism which is capable of performing photosynthesis can digest cellulose as well," he told OurAmazingPlanet.

This trick could come in handy in the production of biofuels like cellulosic ethanol, where expensive enzymes are needed to break down tough cellulose and turn it into simpler sugars that can then be converted to ethanol, Wobbe said. It could also be useful in making biodiesel, since C. reinhardtii is capable of making fats that can be converted into the fuel.

The algae break down cellulose by secreting an enzyme called cellulase, an ability thought to be unique to fungi, bacteria and animals, Wobbe said.

Christoph Benning, a biochemist at Michigan State University who wasn't involved in the research, said the finding wasn't shocking, but hadn't been clearly shown before. "I cannot recall another plant that breaks down cellulose and takes up the sugars," Benning said. "It's not that super-surprising, but I haven't heard anything like it before."

It makes sense that this species could live off of cellulose since it normally lives in the soil, where carbon dioxide and sunlight isn't always readily available, but other plant materials are, said Stephen Mayfield, director of the San Diego Center for Algae Biotechnology.

"The real world is a tough place, it is literally eat or be eaten," he said.  For example, "Two percent of the human genome is dedicated to brain function and 25 percent is dedicated to defense against pathogens (the guys trying to eat us)," he wrote in an email. "That should tell you all you need to know about the world: Everyone is out for a free lunch and it turns out algae is no different."

Reach Douglas Main at dmain@techmedianetwork.com. Follow him on Twitter @Douglas_Main. Follow OurAmazingPlanet on Twitter @OAPlanet. We're also on Facebook and Google+.

This ScienceLives article was provided to LiveScience in partnership with the National Science Foundation.

When people enter microbiologist Gemma Reguera's lab at Michigan State University, one of the first things they notice is that it's staffed nearly with all female researchers. Ever since Reguera was six years old, she knew that she wanted to be a microbiologist. Once her career began in earnest, she also knew that she wanted to be a role model for women in science. And she's been successful on both fronts.

Reguera has also succeeded in deciphering how microbes — specifically Geobacter bacteria — can play a key role in cleaning up nuclear waste and toxic metals. The revelation that Geobacter's conductive pili or nanowires do the hard job of cleanup has put Reguera's research on an interesting course. Reguera is working to improve and patent Geobacter's nanowires, which perform nature's version of electroplating with uranium (an electrochemical process used to make metallic coatings from soluble metals) which effectively immobilizes radioactive material and prevents it from leaching into groundwater.

The next phase of her efforts could lead to microbial fuel cells that generate electricity while cleaning up after environmental disasters — not a bad combination. See a video of Reguera in a recent interview conducted by the National Science Foundation answering the ScienceLives 10 Questions below.

Name: Gemma Reguera Institution: Michigan State University Field of Study: Microbigology

Editor's Note: This research was supported by the National Science Foundation (NSF), the federal agency charged with funding basic research and education across all fields of science and engineering. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author and do not necessarily reflect the views of the National Science Foundation. See the ScienceLives archive.

MINNEAPOLIS — Scientists have embarked on a large-scale project to hunt down and formally identify a mysterious group of microbes whose varieties alone likely number in the millions.

The task is a tricky one because these microorganisms are literally out of sight, because of both their size — like all of their single-celled brethren, they are too tiny to be seen with the naked eye — and where they live.

The project, called the Census of Deep Life, is aimed at quantifying and classifying the microbes that dwell deep beneath both continents and oceans, from around 6 to 60 miles (10 to 100 kilometers) within the Earth's crust. [Infographic: Tallest Mountain to Deepest Ocean Trench]

Denizens of the deep

Little research has been done to identify the unicellular denizens of the Earth's inhospitable depths. An ocean microbe census indicated that as many as a billion kinds of microorganisms live in the planet's seas, but the deep Earth is more difficult to access, and microbial populations are more sparsely distributed.

Yet the data that are available on crust-dwelling species suggest that as many as several million categories of bacteria and their unicellular relations could live in the planet's deeps.

"This is what you could call 'invisible life' — without the right tools," said project head Rick Colwell, a geomicrobiologist at Oregon State University who gave a talk here yesterday at the meeting of the Geological Society of America. "Occasionally they accumulate in enough quantity where you can actually see them — in biofilms — but usually they're discrete, minute cells."

Researchers have their work cut out for them, and not just because their quarry lives in such exotic locales.

Because microbes find sneaky ways of swiftly altering their genetic code, it can be a slippery business to identify a microbe "species," Colwell told OurAmazingPlanet.

However, microorganisms don't bend all the rules that govern larger life forms, he said.

"They require some way of collecting energy, they evolve, they grow, they have capabilities of replicating their DNA," Colwell said.

Drilling down

The project is inspired, in part, by the Census of Marine Life, a massive, decade-long investigation into what lives in Earth's oceans. Over the course of the study, scientists from 80 countries found more than 6,000 potentially new species in ocean waters, and completed formal descriptions of more than 1,200.

For the census-takers of microbes, it's a huge challenge to identify distinct species.

"Microbiologists have tried to do so the way traditional biologists have, but they're frustrated by this because microorganisms tend to trade DNA," Colwell said. In fact, microbes can swap DNA by merely engaging in what amounts to hand-holding.

Such a cavalier exchange of genetic material makes it difficult to unequivocally differentiate one group of microorganisms from another.

However, the microbe census is focused on getting samples from deep, isolated communities that have been left to their own evolutionary devices for long periods of time, and may have distinctive genetic characteristics.

The project receives rock and fluid samples retrieved from diverse environments such as caves, mines, and drill projects on land, and from projects in the ocean that have drilled deep beneath the seafloor.

Once the samples are in the lab, researchers have a suite of techniques at their disposal to hunt around for microbe DNA, and specifically for 16S rRNA, a gene that Colwell called "card-carrying evidence that you are alive."

And although microbes are indeed alive, finding a good way to classify them is a challenge. Even saying that one has identified a species can prove provocative among those who study them, Colwell said.

"We really are still struggling with this concept," he said.

This story was provided by OurAmazingPlanet, a sister site to LiveScience. You can follow OurAmazingPlanet staff writer Andrea Mustain on Twitter: @andreamustain. Follow OurAmazingPlanet for the latest in Earth science and exploration news on Twitter @OAPlanet and on Facebook.

The worms in microbiologist Marie-Anne Felix's lab are feeling a little under the weather. It seems they've picked up a stomach virus. The virus is actually the first ever found to infect the nematode C. elegans, a carefully studied worm that scientists use for basic research.

Studying the sick worms will teach researchers how viruses interact with their hosts — which, in some cases such as HIV and influenza, are humans.

While viruses — unique forms of life that cannot grow or reproduce outside a host cell — infect everything from bacteria to plants and mammals, researchers had been unable to find any that infected this nematode.

"Prior efforts didn't look with the right tools and didn't look in the right place," study researcher David Wang, a microbiologist at Washington University School of Medicine in St. Louis, told LiveScience. "We have a combination of expertise." Felix is a worm specialist, and Wang, a virus hunter.

C. elegans is one of the most studied organisms on the planet (and even off the planet). Researchers have sequenced its genome and documented the development of each of its cells. They can turn on and off most of its genes at will, through a process called RNA interference (or RNAi).

This interference process also happens naturally in many organisms. Some, like plants and fruit flies, use RNAi to fight off viruses. In these organisms, the RNAi can turn off the genes of the invading virus, stopping it in its tracks.

Studying how the newly discovered virus interacts with such an essential RNAi model system as the nematode could shed light on how RNAi is used in humans, Wang said. "This has the potential to teach us something fundamentally new about how organisms respond to viral infections," he said. "There might be parallel pathways in humans."

Felix, of the Jacques Monod institute in Paris, found the virus in sick worms she had collected from rotting apples and grapes. She could tell the worms were sick, but they didn't get better after a course of antibiotics. She was able to infect other C. elegans worms with a mix from mashed-up infected worms that had been filtered to remove anything larger than a virus (about 20 nanometers, or the width of a very thin human hair). Even after being filtered, the liquid could make worms sick.

Felix asked Wang to try to identify the virus that made it through the filter. He found that it was a type called Nodaviridae, which infect insects and fish, though it is only about 40 percent similar to previously known nodaviruses. The virus, and its closely related cousin the team discovered was infecting the nematode C. briggsae, might even be a completely new family, Wang said.

The virus easily infects the wild worms, though once they did they only caused changes in the gut cells. The worms still lived long and seemingly happy lives, although with fewer offspring.

The commonly used lab strain of C. elegans was less susceptible to the virus, but another strain, which is RNAi-deficient, was more susceptible.

Because of this, it seems likely the worms use RNAi in the same anti-viral way that Drosophila and plants do. Because the C. elegans is such a well-defined model system, researchers can see which genes make the worm more or less susceptible to its viral invaders.

"It adds an approach to the repertoire of tools that researchers can use to understand virus-host interactions" in humans, Wang said.

Dennis Kim, a researcher who studies bacterial infections of C. elegans at MIT, noted in an e-mail to LiveScience that the system "will provide insights into the ecology and evolution of host-virus interactions." Kim was not involved in the current study.

Wang agreed, but noted that studying host-virus interactions in C. elegans "has the limitations of a model organism, in that we might find things that are only applicable to the model." Still, he said, most of the fundamental processes of viral infection should be similar in humans.

The paper was published today (Jan. 25) in the journal PLoS Biology.

You can follow LiveScience Staff Writer Jennifer Welsh on Twitter @microbelover.

This Behind the Scenes article was provided to LiveScience in partnership with the National Science Foundation. We are back again. This is our second Atlantic crossing, all to get some mud from the very middle of this ocean. I could not be happier to be right here, in the center of this great blue sea. We are a multidisciplinary, German-American team of oceanographers, a cast of microbiologists, biogeochemists, organic geochemists, geophysicists, and petrologists, all here to "survey" a tiny wedge of sediments and the underlying basement rock at 22°N on the western flank of the mid-Atlantic ridge that is called "North Pond."   This site is just one among a little cluster of ponded sediments in the region, each flanked by 1,500-meter rocky mountains on all sides. Our survey work here has very specific objectives — to gather enough data about North Pond to plan in detail a complex expedition we are planning with the Integrated Ocean Drilling Program (IODP), funded in large part by the National Science Foundation. I am a geobiologist from the University of California, here with two other USC colleagues — Wiebke Ziebis, a biogeochemist, and a postdoc from my lab Nina Knab.   We are part of the microbiology/biogeochemistry team, here to characterize and describe life in ancient sediments and rock. I am known as the rock woman — or iron maiden — for my interests in microbes that live in the cracks and pores of volcanic rocks at the ocean floor, my favorite among these microbes being ones that eat iron for a living.   Finding life in the crust beneath the seas We are getting a first glimpse at what kind of life and chemical processes exist in dark, deep waters, in the ocean crust that lies under some of the most starved portions of the world’s oceans — the north Atlantic gyre — where blue waters reign because of the extremely low abundance of water plants.   We will do basic surveys, figuring out what kind of microbes persist in the sediments and rock that underlay this barren ocean region. It was thought not long ago that subsurface rock and sediments were devoid of life. Now we know otherwise — life can persist kilometers below the bottom of the seas.   Calculations have suggested that if what scientists have observed in a few deep cores is representative of biology in the subsurface generally, then as much as one third of the Earth’s total biomass may be buried, alive, beneath the ocean floor.   Getting to the core of the survey But the data are few … and scattered. That is what we are here to change. We are here to do a census, in part:  microbes stand up and be counted! But we also want to figure out what they are doing down there, and figure out what the consequence of their existence is for the rest of the planet.   For example, the global biogeochemical cycles of carbon, nitrogen, iron, sulfur — all may be influenced or controlled by these intra-terrestrial mighty microbes.   We don't know much about life in rock in the deep sea — but what we do know is that ocean water actively flows in rock below the bottom of the ocean. It is called the "superhighway" of fluids, and is the largest aquifer on this planet.   The water we know is flowing, carrying tiny particles along for the ride. Microbes are among those tiny particles that must flow through, but do they take "seed"?  Like biofilms that form on drinking water systems as water flows through them, clogging and making mineralized deposits that cause corrosion, I suspect something very similar is happening in the pore spaces of volcanic rock below the bottom of the ocean — can we prove it?   Yes we can, but not overnight.   This project is the first of its kind, and this cruise is only first step in a 10-year plan to answer these and other questions about the mighty microbes of the intra-terrestrial underworld.   Step one, collect muds — check! Step two, drill holes in rock. I cannot wait to get back here with the IODP drill ship, the Joides Resolution. Yes indeed we are going to be back here to drill, baby, drill!  Mighty microbes watch out — your secrets are going to be revealed. Read Katrina’s blog archive at: http://northpondexpedition.usc.edu/.

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Editor's Note: This research was supported by the National Science Foundation (NSF), the federal agency charged with funding basic research and education across all fields of science and engineering. See the Behind the Scenes Archive.

Being tiny has its advantages, and a newly discovered microbe in Greenland has exploited this fully. The bacterium survived more than 120,000 years beneath the ice where inhospitable conditions reach new lows.

Most organisms constantly deal with trade-offs, such as some hot-desert residents that take advantage of sunshine yet must endure dehydration.

The new microbe makes dehydration seem like a walk in the park. Called Chryseobacterium greenlandensis, the tiny bacterium was found 2 miles (3.2 km) beneath a Greenland glacier. There, conditions are extreme, with temperatures below 16 degrees F (-9 degrees C), high pressure, very little oxygen and meager food.

The ultra-small size of the new species — about 10 to 100 times smaller than E. coli bacteria — could explain why it was able to gain a foothold in such harsh conditions and survive for so long, scientists say. Tiny microbes like this one likely can more efficiently absorb nutrients due to a larger surface-to-volume ratio. They also may be able to hide more easily from predators and take up residence in microenvironments, such as microscopic veins or cracks in the ice.

"These organisms end up in the ice, because they were deposited there when the glacier was being formed," said Penn State researcher Jennifer Loveland-Curtze. "If they were extruded into the veins, then that would be a place they might have been able to survive." Liquids in these veins often contain nutrients.

Loveland-Curtze, Penn State researcher Jean Brenchley and colleagues analyzed the genetic, physiological, biochemical and structural features of the new species. They hope to learn more about how cells survive extreme life, and ultimately, how life, in general, could survive in extreme environments on Earth and beyond.

"These very icy environments, the glaciers and permafrost, are great analogs for say Mars or Europa and even planets in solar systems we don't even know about yet," Loveland-Curtze told LiveScience.

Fewer than 8,000 species of microbes, out of the estimated 3 million presumed to exist on Earth, have been identified to date. And only 10 or so microbe species originating in polar ice and glaciers have been described.

Loveland-Curtze will present the research this week at a meeting of the American Society for Microbiology in Boston. The study was supported by the National Science Foundation, U.S. Department of Energy and NASA.

Last week, a different group announced that microbes are far more abundant on the seafloor than was expected.

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Like tiny mail-carriers, viruses are able to carry packages of genes around the world, delivering the keys of evolution to other organisms.

This finding comes from a new study of the viruses and bacteria found in nine distinct locations on Earth (such as mines, ponds, oceans, reefs and even human bodies) and sheds light on the complex power swaps among viruses called phages and their bacterial hosts.

Bacteria are tiny, one-celled living organisms whose bodies are much more complex than those of viruses. The largest viruses are about the size of the tiniest bacteria. And while antibiotics can usually kill bacteria, they have no effect on viruses.

"These viral populations seem to be serving as reservoirs of genes that the microbes use," said co-researcher Forest Rohwer, a biologist at San Diego State University. With an estimated millions upon millions of phages (10 followed by 30 zeros) on Earth, the potential impact of such genetic transfers by viruses is huge, Rohwer points out.

"We've found previously that the viruses can move between biomes [ecological communities] pretty easily," Rohwer told LiveScience. "So in theory they should be able to move things from one part of the world to another."

That means genes that would confer environmental protection or some other adaptive tool could trek long distances via viruses from bacteria in one part of the world to another region.

The study is detailed online today by the journal Nature. Distinct profiles

The researchers collected samples of bacteria and viruses from nine major ecological communities: underground mines, highly saline ponds, coral reefs, oceans, bodies of freshwater, fish farms, humans and mosquito-associated areas, and sedimentary "fossils," which contain records of microbial life on Earth.

Using a technique called metagenomics, the team identified the genes and their relative abundances for entire communities of bacteria and viruses found in each environment.

The genetic profile for each biome was found to be distinct.

"If you took a sample and you didn't know where that sample was from, you could actually predict where it was from with the metagenome," Rohwer said.

Sharing genes

The team then focused on the abundant genes from each environment to learn more about their known functions.

"There are a whole bunch of genes the viruses are carrying that we would've never expected," Rohwer said. "These are things that at first glance don't seem to be important to the virus life cycle."

In some of the samples, the viruses were equipped with genes normally associated with movement and direction in bacteria. "We're finding those genes in the viruses, which suggests that the viruses, when they're doing infection, they're actually manipulating the behavior of the bacteria when they're in them," Rohwer said.

In fish farms, the researchers found the viruses delivered "eating" genes to bacteria. The genes allowed bacteria to take advantage of so-called taureen, a sulfur-based acid added to fish food and not normally a part of the microbe's diet.

Viruses hanging out in coral-reef systems held a stash of genes for mucus eating. The genes were also found in the environment's bacteria, suggesting the viruses transferred the genes to the bacteria. In that way, the bacteria could slurp up mucous-like substances produced by coral.

"During infections by the viruses, there are many times when those infections don't lead to the viruses killing the cells," Rohwer said. "And under those circumstances, there's a chance that the bacteria can incorporate the genes the virus is carrying."

The project was supported by the Gordon and Betty Moore Foundation, the National Science Foundation, U.S.D.A. Cooperative State Research, the National Institute of Allergy and Infectious Diseases, the National Institutes of Health and the U.S. Department of Health and Human Services.

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Microbes might be tiny and hard to see, but they account for a large percentage of Earth's biodiversity. They have been living on the planet for 3.8 billion years compared to 200,000 for humans, and for most of the Earth’s existence, they have been the only form of life around.

In fact, all life on Earth today, including trees and fish and people, is thought to have evolved from the earliest microbes.

The term “microbe” describes bacteria, archaea, single-celled eukaryotic organisms such as amoebas, slime molds and parameciums, and even viruses by some broad definitions. (Viruses are disputed because they are considered non-living and cannot replicate on their own, but the field of microbiology usually includes the study of viruses.) Most microbes are unicellular, meaning one cell comprises each individual.

They are found almost everywhere on Earth, in soils, plants, geysers, ocean depths, frigid seas below Antarctic ice and in our bodies. (Trillions of bacteria have been found in our guts.) Some microbes, called extremophiles, are found in places where no other living organisms can survive—in boiling hot hydrothermal vents in the ocean and in rocks deep underground.

They can be helpful and/or harmful to other living things: bacteria such as Streptococcus and E. coli can infect and even kill humans, and algal blooms can be toxic to fish and deplete the water of oxygen, but other bacteria help us digest our food and replenish nutrients in soil, and some can help clean up oil spills.

Scientists are continually discovering new species, genuses, families and orders of microbes, with no end in sight. Because they have been around for so long, microbes evolve in more complicated ways than multicellular life—they can transfer genes between species and from one individual to another, something humans certainly can’t do.

Understanding microbes is critical to understanding how ecosystems function, how to combat disease and how infectious diseases, such as bird flu, emerge and spread.

Yellowstone's hot springs are known to harbor extreme creatures that paint the water shades of red, orange and green. Now scientists have discovered a new type of bacteria with light-harvesting antennae. 

The oddity among oddities adds to a short list of microbes that can transform light into chemical energy, a process called photosynthesis that's usually attributed to green plants and their chlorophyll.

The finding is detailed in the July 27 issue of the journal Science.

The bacteria, Candidatus Chloracidobacterium (Cab.) thermophilum, belong to the Acidobacteria phylum, which until now was not known to include any chlorophyll-producers. The addition means that six of 25 bacteria phyla now contain light-harvesting members.

"Finding a previously unknown, chlorophyll-producing microbe is the discovery of a lifetime for someone who has studied bacterial photosynthesis for as long as I have (35 years)," said lead study author Don Bryant of Penn State University.

Bryant and his colleagues spotted the bacteria in three hot springs in Yellowstone National Park—Mushroom Spring, Octopus Spring and Green Finger Pool—which are located not far from the Old Faithful Geyser.

Along with fellow light-harvesting microbes called cyanobacteria, the newbies dwell near the surface of bacterial mats, where light and oxygen are plentiful. Temperatures there soar from 122 to 151 degrees Fahrenheit (50 to 66 degrees Celsius).

The scientists sequenced DNA from the cells of the bacteria, focusing on two genes, one a crucial component of the protein-making machinery and the other a gene essential for converting light energy into chemical energy.

The bacteria sport light-harvesting antennae called chlorosomes, which each contain about 250,000 pigments. Until now, the chlorophyll-packed structures haven't been found in any aerobic, or oxygen-tolerant, microbes. 

The team found the bacterium makes two types of chlorophyll, explaining how it can thrive alongside other species in microbial mats and compete for light with cyanobacteria.

"The closest relatives of Cab. thermophilum are found around Mammoth Hot Springs in Yellowstone and hot springs in Tibet and Thailand," Bryant said. "As we look more closely, we may find relatives of Cab. thermophilum in the microbial mats of thermal sites worldwide."

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Saltwater algae are biological Transformers that can shrink or expand in size to defend against the eating habits of hungry predators.

The technique makes the saltwater alga species Phaeocystis globosa almost 100-times less likely to be eaten, a finding detailed the June 11 online version of the Proceedings of the National Academy of Sciences.

"Not only do these single celled organisms recognize danger, they identify the species of the attacker and, depending on the species, respond in opposite ways,” said researcher Mark Hay, a Georgia Institute of Technology marine biologist. "These things are really assessing the context of their environment to advantage themselves and disadvantage their enemies."

Two predators feed on these algae: large protozoa called ciliates and small crustaceans called copepods. Ciliates have a taste for small cells of algae, whereas copepods prefer to eat large, ball-shaped colonies.

Researchers found that algae sensing chemical attack signals from ciliates grew large enough to be too big for ciliates to consume. But when the algae sensed the approaching chemicals of attacking copepods, they shrunk in size. The change in size took three to six days.

“When one of these cells changes to the biggest colony form, although it takes a while, it’s like changing from [the size of] a mosquito to 76 blue whales or 3,000 bull elephants,” Hay said. “That’s a pretty dramatic difference.”

The incredible performance of the algae could help researchers better understand changes in climate change related to the carbon cycle in cold oceans.

Until now, biologists have been conflicted as to whether the carbon seized in saltwater algae moves up the food chain, or whether it sinks, unused, to the bottom of the ocean.

"I think both of the theories are right," Hay told LiveScience.

When small creatures such as ciliates feed on carbon-rich algae, the carbon rises up the food chain as it's eaten by larger and larger marine life, including fish. Many of these fish live near the surface of the oceans, where warmer water can hold much less carbon dioxide than colder, deeper waters. The carbon in the fish is easily released into the air and will eventually contribute to greenhouse gases in the atmosphere.

But the algae and carbon consumed by larger copepods end up in fecal packages that sink down to the depths of the ocean, where carbon is stored more securely and less likely to escape into the atmosphere.

"It depends on what form the alga are in," Hay said. "This is an example of the biological context being tremendously important."

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