The family methanospirillaceae

Abstract

The family Methanospirillaceae consists of a single genus: Methanospirillum. As of December 2013, this genus contained two species, descriptions of two more species being in press. This family of mesophilic and neutrophilic methanogens belongs to the order Methanomicrobiales. The members are long slender curved rods surrounded by an S-layer. Cells form long filaments, kept together by a common sheath composed of stacked hoops. Within the filaments, the individual cells are separated by complex spacer plugs composed of proteinaceous disks that span the sheath and consist of paracrystalline layers sandwiched between amorphous layers of unknown composition. Methanogenesis from H2/CO2 is the main energy-generating process. Some species can also use formate, and secondary alcohols + CO2 are used by a few strains. Methanospirillaceae are found in anaerobic waste treatment systems and in wetland soils.