Methanospirillum

In taxonomy, Methanospirillum is a genus of microbes within the family Methanospirillaceae. All its species are methanogenic archaea. The cells are bar-shaped and form filaments. Most produce energy via the reduction of carbon dioxide with hydrogen, but some species can also use formate as a substrate. They are Gram-negative and move using flagella on the sides of the cells. They are strictly anaerobic, and they are found in wetland soil and anaerobic water treatment systems.