Desulfotomaculum

Desulfotomaculum is a genus of Gram-positive, obligately anaerobic soil bacteria. A type of sulfate-reducing bacteria, Desulfotomaculum can cause food spoilage in poorly processed canned foods. Their presence can be identified by the release of hydrogen sulfide gas with its rotten egg smell when the can is first opened. They are endospore-forming bacteria.

In 2005, a new strain of Desulfotomaculum, called Desulforudis audaxviator, was discovered during drilling 2.8 km deep in the Mponeng gold mine in South Africa. The strain, found in water which has been isolated for tens of millions of years, exists completely independent of photosynthesis. The bacteria use radiolytically produced hydrogen gas, which is generated in that environment by the energy released by radioisotopes. The bacteria also use sulfates. Sulfates may be generated both by the energy released by radioisotopes as well as by other chemical reactions. Generated hydrogen sulfide may be a continuous energy source for this organism. Some organisms can obtain energy from sources other than from the sun or other stars, which means similar lifeforms may be found on other planets in the Solar System and elsewhere.