New Extremeophiles: living under glaciers (Introduction)

by David Turell , Tuesday, December 22, 2020, 19:05 (1219 days ago) @ David Turell

Making hydrogen gas and combing it with carbon dioxide:

https://phys.org/news/2020-12-hydrogen-supported-life-beneath-glaciers.html

"The work examines the ways water and microbes interact with the bedrock beneath glaciers, using samples of sediment taken from glacial sites in Canada and Iceland.

"'We kept finding organisms in these systems that were supported by hydrogen gas," said Boyd of the inspiration for the project. "It initially didn't make sense, because we couldn't figure out where that hydrogen gas was coming from under these glaciers."

"A team of researchers, including Boyd, later discovered that through a series of physical and chemical processes, hydrogen gas is produced as the silica-rich bedrock underneath glaciers is ground into tiny mineral particles by the weight of the ice on top of it. When those mineral particles combine with glacial meltwater, they let off hydrogen.

"What became even more fascinating to Boyd and Dunham was that microbial communities under the glaciers could combine that hydrogen gas with carbon dioxide to generate more organic matter, called biomass, through a process called chemosynthesis. Chemosynthesis is similar to how plants generate biomass from carbon dioxide through photosynthesis, although chemosynthesis does not require sunlight.

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"'The organisms we were interested in rely on hydrogen gas as food to grow, and most are also anaerobes, meaning oxygen will kill them," said Dunham,

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"'Considering that glaciers and ice sheets cover about 10% of the Earth's landmass today, and a much larger fraction at times in the planet's past, microbial activities such as the ones Eric measured are likely to have had a major impact on Earth's climate, both today and in the past," said Boyd. "We've known for a while that microorganisms living beneath ice sheets or glaciers can fix carbon, but we never really understood how. What Eric's pioneering work shows is that not only are these organisms completely self-sustainable in the sense that they can generate their own fixed carbon, they also don't need sunlight to do it like the rest of the biosphere that we're familiar with.'"

Comment: Extremeophiles never cease to amaze.