We cannot see them, but they are everywhere. They were the first to inhabit our planet and are able to survive in themore extreme conditions, from the super salty waters of the Dead Sea to the last corner of our stomachs. We are talking about microorganisms, tiny beings that are everywhere and live in the most unexpected places.
Scientists estimate that one third of terrestrial organisms live in rocks and sediments. However, the day to day of these survivors is a mystery. Now a work published in the magazineProceedings of the National Academy of Sciencessheds some light and reveals for the first time some details of the life of microbes that produce methane and live in the deepest crevices of underwater volcanoes.
“We were interested in microorganisms in deep rocks, and the best place to study them is in thehydrothermal vents and underwater volcanoes. Hot water provides them with the energy and nutrients they need, “explains James Holden, one of the authors, from the University of Massachusetts-Amherst.
The scientists took samples of hydrothermal fluids in the Axial volcano and in the Endeavor segment, which are located in an underwater mountain range near the Oregon coast (USA) and more than a kilometer deep. Samples flowed infumaroles with a temperature of up to 350 degreesand in cracks on the seabed with somewhat lower temperatures, which indicates that the organisms that live there arehyperthermophiles, that is, capable of withstanding a lot of heat.
Clues to life millions of years ago
Among the most interesting results, researchers have described a mutually beneficial relationship between these organisms: some species ‘make their living’ by feeding on the hydrogen residues produced by others. Many of these organisms are methanogens, that is, they inhale hydrogen and carbon dioxide and produce methane as waste.
In addition to shedding light on the biological processes that take place in these harsh environments, these works could help us imagine what life was like on our planet millions of years ago , understand the origin of our atmosphere as we know it today, and even guess the type of organisms that could inhabit other planets .
