An Extremophile Post for Carlos

Long-Term Sustainability of a High-Energy, Low-Diversity Crustal Biome

Li-Hung Lin,1,2* Pei-Ling Wang,3 Douglas Rumble,4 Johanna Lippmann-Pipke,5 Erik Boice,6 Lisa M. Pratt,6 Barbara Sherwood Lollar,7 Eoin L. Brodie,8 Terry C. Hazen,8 Gary L. Andersen,8 Todd Z. DeSantis,8 Duane P. Moser,9 Dave Kershaw,10 T. C. Onstott1

Geochemical, microbiological, and molecular analyses of alkaline saline groundwater at 2.8 kilometers depth in Archaean metabasalt revealed a microbial biome dominated by a single phylotype affiliated with thermophilic sulfate reducers belonging to Firmicutes. These sulfate reducers were sustained by geologically produced sulfate and hydrogen at concentrations sufficient to maintain activities for millions of years with no apparent reliance on photosynthetically derived substrates.

1 Department of Geosciences, Princeton University, Princeton, NJ, USA.
2 Department of Geosciences, National Taiwan University, Taipei, Taiwan.
3 Institute of Oceanography, National Taiwan University, Taipei, Taiwan.
4 Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC, USA.
5 GeoForschungsZentrum Potsdam, Telegrafenberg, Potsdam, Germany.
6 Department of Geological Sciences, Indiana University, Bloomington, IN, USA.
7 Department of Geology, University of Toronto, Toronto, ON, Canada.
8 Ecology Department, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
9 Division of Earth and Ecosystems Sciences, Desert Research Institute, Las Vegas, NV, USA.
10 Mponeng Mine, Anglo Gold, Johannesburg, South Africa.

One critter apparently uses uranium to get useful energy from water. From the newsletter at work:

In their paper, the researchers and their collaborators describe a community of bacteria from the species known as Firmicutes that lives in a South African mine 2.8 kilometers below the earth’s surface and uses radioactive uranium to convert water molecules to useable energy. The discovery expanded the realm of Earth's biosphere, the three-dimensional shell that encompasses all planetary life.

I wonder what sort of SFnal ecology you could use if this is scalable to larger organisms with enough uranium around and water around.