New Extremophiles: living in lava tubes (Introduction)

by David Turell , Wednesday, July 28, 2021, 15:39 (997 days ago) @ David Turell

Eating rock:

https://www.insidescience.org/news/life-lava-caves-ignores-food-surface-eats-rock-instead

"researchers found that many bacteria growing on the walls of lava caves spurn the feast flowing over them. Instead, they produce their own energy from surrounding minerals or dissolved chemicals and build the molecules they need using carbon in the air or rock.

"'This means that even in a very well-connected environment in the shallow subsurface, we still have evidence for life that is very independent from the surface living and thriving," said Matthew Selensky, a geobiologist and doctoral candidate at Northwestern University in Evanston, Illinois.

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"'Organisms that use other sources of energy besides solar energy exist pretty much everywhere on the planet," said Caitlin Casar, who earned her doctorate in the same lab as Selensky but was not involved in the new study. "You can find them at the surface of the Earth, you can find them in soil, you can find them deep in the Earth's crust, you can find them at the bottom of the ocean, in the ocean's water column, in the air."

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"...the researchers found that the water seeping in from the surface was full of carbon that had been fixed by plants or other photosynthetic organisms using the Calvin cycle. Some cave features appeared to contain microbes that lived off this surface food, "sort of fighting for table scraps," said Selensky. But in biofilms, some types of molecules the researchers examined had C-13 levels that were much lower. This indicates that a large fraction of the bacteria in the biofilms were surviving off the minerals and CO2 in the cave -- a lifestyle known as chemolithoautotrophy, or lithoautotrophy for short, according to Selensky.

"'The assumption for a lot of people is that if you're on the surface or close to the surface, you have this amazing energy source, the sun … and essentially photosynthesizers can outcompete everything else," he said. "I do think that lithoautotrophy is almost an underestimated metabolism in these environments.'"

Comment: no surprise to us. Organisms can live anywhere they wish. Life was designed to appear and survive from the beginning. Only by design.