MethanogeniumMethanogenium is a genus of archaeans in the family Methanomicrobiaceae. The type species is Methanogenium cariaci.Description and habitatThe species within Methanogenium are coccoid in shape and Gram-negatives and, like other methanogenic archaea, they produce methane from carbon dioxide, hydrogen or formate as substrates. Although they occasionally have flagella, they are non-motile. They are strictly anaerobic, and can be found in marine and lake sediments that lack oxygen.PhylogenyThe currently accepted taxonomy is based on the List of [Prokaryotic names with Standing in Nomenclature] and National [Center for Biotechnology Information].