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.^{[citation needed]} 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.^{[citation needed]}

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.^[3] The bacteria uses radiolytically produced hydrogen gas, which is generated in that environment by the energy released by radioisotopes. The bacteria also uses 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.^[4] 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.

Desulfotomaculum present as straight or curved rods. They are highly heat resistant and free-living fixers of atmospheric nitrogen. They are motile with a peritrichous flagella and are common inhabitants of soil, water, geothermal run-off, insect intestines and in rumen. They also cause "sulphide stinker" spoilage of canned foods.

The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN)^[2] and National Center for Biotechnology Information (NCBI).^[1]

Unassigned species:

• D. carboxydivorans Parshina et al. 2005
• "D. copahuensis" Willis Poratti et al. 2016
• D. arcticum synonym of Desulfotruncus arcticus (Vandieken, Knoblauch & Jorgensen 2006) Watanabe, Fukui & Kuever 2021
• D. geothermicum synonym of Desulfoscipio geothermicus (Daumas, Cord-Ruwisch & Garcia 1990) Watanabe, Fukui & Kuever 2021
• D. halophilum synonym of Desulfohalotomaculum halophilum (Tardy-Jacquenod et al. 1998) Watanabe, Kojima & Fukui 2018
• D. thermoacetoxidans synonym of Desulfofundulus thermoacetoxidans (Min & Zinder 1995) Watanabe, Kojima & Fukui 2018

• List of Bacteria genera
• List of bacterial orders

• Madigan M; Martinko J, eds. (2005). Brock Biology of Microorganisms (11th ed.). Prentice Hall. ISBN 978-0-13-144329-7.
• "Gold mine holds life untouched by the Sun". New Scientist. 19 October 2006. Retrieved 6 September 2016.
• "Bacteria that use radiated water for food discovered two miles down". Phys.org. 19 October 2006. Retrieved 6 September 2016.