image: Kötlujökull, the fourth largest glacier in Iceland, hosts abundant microorganisms sustained by hydrogen produced by weathering of basaltic bedrock view more
Credit: Image credit: Eric S. Boyd.
A study finds that hydrogen derived from basaltic rocks can support microbial life in the absence of sunlight. Microbial communities without access to sunlight use different pathways to generate the energy needed for life, including deriving chemical energy from rock. Hydrogen, a reductant that is commonly used in biochemical reactions, can be generated by the reaction of water with reactive mineral surfaces such as those formed by the erosion of rock by glaciers. Eric S. Boyd and colleagues sampled meltwater outflows from glaciers overlaying different rock types and found that dissolved hydrogen concentrations were an order of magnitude higher in meltwaters from a basaltic rock catchment than those of a carbonate rock-based catchment. Further, the microbial communities in the streams from basaltic catchments were better adapted to use hydrogen to fuel their metabolisms than microbes from the carbonate catchment. An experiment with basaltic sediments, hydrogen, carbon dioxide, and ferric iron minerals showed that such a combination produced a microbial population that used metabolic pathways previously thought to be restricted to microbes in hot or highly acidic environments. According to the authors, the results show how rock-derived hydrogen can support microbial life in dark environments and particularly under glaciers, suggesting a mechanism for the survival of life under global glacial conditions and on icy extraterrestrial planets.
###
Article #20-07051:
"Lithogenic hydrogen supports microbial primary production in subglacial and proglacial environments," by Eric C. Dunham, John E. Dore, Mark L. Skidmore, Eric E. Roden, and Eric S. Boyd.
MEDIA CONTACT:
Eric S. Boyd,
Montana State University,
Bozeman, MT;
tel: 406-994-7046;
e-mail: <eboyd@montana.edu>