Real Dictionary

methanogen in American English
an anaerobic microorganism that lives on carbon dioxide and hydrogen and gives off methane, found in swamp sediment, cows' stomachs, etc.
noun: any of a diverse group of widely distributed archaebacteria that occur in anaerobic environments, as the intestinal tracts of animals, freshwater and marine sediments, and sewage, and are capable of producing methane from a limited number of substrates, i