Methanolacinia is a genus of archaeans in the family Methanomicrobiaceae. The cells are bar-shaped and irregular 0.6 üm in diameter and 1.5âÂÂ2.5 üm in length. They do not form endospores. Most are non-motile, but some have a single flagellum. They are strictly anaerobic. They produce methane through the reduction of carbon dioxide with hydrogen and cannot use formate, acetate or methyl compounds as substrates.