Methanogenesis -In some bacteria oxidation of hydrogen takes place using CO2 as the terminal electron acceptor. CO2 is reduced and methane is produced. Methanobacteria are found in the intestines of animals, soil, black pond muds, faces and in anaerobic sewage tanks. They are autotrophs, since they only use CO2 as the source of carbon, and are probably the most strictly anaerobic organisms known.
