Methanobacteriaceae

Archaea bacteria containing gram-negative and gram-positive, motile or nonmotile, strictly anaerobic rods and cocci, which obtain energy either by the reduction of carbon dioxide to form methane or by the fermentation of compounds such as acetate and methanol with the production of methane and carbon dioxide; they are found in anaerobic habitats such as sediments of natural waters, soil, anaerobic sewage digestors, and the gastrointestinal tract of animals.