The family methanomicrobiaceae

The family Methanomicrobiaceae currently (December 2013) consists of six genera: Methanomicrobium, Methanoculleus, Methanofollis, Methanogenium, Methanolacinia, and Methanoplanus, with, respectively, 1, 9, 5, 4, 1, and 3 species (not including later subjective synonyms). This family of mesophilic or moderately thermophilic and neutrophilic methanogens belongs to the order Methanomicrobiales. The members are rod shaped or irregular coccoid in shape. Cells possess a protein S-layer wall. Methanogenesis from H₂/CO₂ or from formate is the major energy-generating process; some species can also use primary or secondary alcohols as the electron donor for the reduction of CO₂ to methane. Acetate and other growth factors may be required. Members of the Methanomicrobiaceae have been found in a wide variety of anaerobic environments where methane is produced: the rumen of ruminant animals, anaerobic marine sediments, wetlands, oil wells, and others.