On Earth, some organisms like it hot, some like it cold, and others feel at home only among the scalding acid jets of an undersea volcano.
That latter group — an ancient and eclectic bunch known as extremophiles — thrives in conditions that would kill your average Earthling. Members of the group tend to be microscopic in scale, and they include radiation-resistant tardigrades, pressure-loving prokaryotes at the bottom of the Mariana Trench and the acid-slurping bacteria that make Yellowstone's Grand Prismatic Spring so colorful.
Now, researchers exploring a deep-sea volcano near New Zealand have inducted almost 300 new extreme-living microbes into that bizarre club.
In a study published Dec. 22, 2020, in the journal Proceedings of the National Academy of Sciences, marine biologists used a remotely operated robot to scrape sediment from a 6,000-foot-deep (1,800 meters) collection of hydrothermal vents called Brother's Volcano, located about 200 miles (320 kilometers) northeast of New Zealand. In a subsequent DNA analysis of the volcanic sediment, the team identified 285 different types of novel microbes previously unknown to science. The new extremophile haul includes 202 potential new species of bacteria and 83 species of archaea (ancient single-celled microbes that tend to live in extreme environments).
Similar to the diverse cast of microbes living in Grand Prismatic Spring, different types of microbes seemed to congregate at different parts of Brothers Volcano, depending on the temperature and acidity of the surrounding water, the team found. Certain species favored the walls of the volcano's caldera, which is pocked with 65-foot-tall (20 m) chimneys constantly spewing out 600-degree Fahrenheit (320 degrees Celsius) fluid filled with metals. Other species preferred swimming through the sulfur gases leaking out of two large mounds near the caldera's center. (The water temperature near those mounds was a breezy 250 F, or 120 C.)
Besides adding so many new species to the tree of microbial life, these findings could give researchers another tool with which to study Earth's most extreme places, the researchers wrote. Because certain microbes sharing certain genetic traits seemed to thrive in specific conditions in Brothers Volcano, it follows that researchers could infer a lot about an extreme habitat's conditions merely by studying the microbes that live there.
"We're heading to a point where microbes can be very informative about the environment they came from," study co-author Mircea Podar, a systems geneticist at the Oak Ridge National Laboratory in Tennessee, said in a statement. "With more data, we can use microbes as a proxy to characterize environments where traditional measurements are challenging to capture."
Originally published on Live Science.