METHANOSAETA-CONCILII GEN-NOV, SP-NOV (METHANOTHRIX-CONCILII) AND METHANOSAETA-THERMOACETOPHILA NOM-REV, COMB-NOV

Methanosaeta concilii gen. nov., sp. nov. ('Methanothrix concilii') is described. Cells of species in the genus Methanosaeta are obligately anaerobic, gram-negative, nonmotile rods (length, 2.5 to 6.0 μm) with flat ends. The cells are enclosed within a proteinaceous, cross-striated sheath. Growth can occur as long filaments which represent chains of individual cells separated by spacer plugs and continuously enclosed by the tubular sheath. Acetic acid is used as the sole source of energy; its metabolism results in the production of about equimolar amounts of CH4 and CO2. Acetic acid and CO2 are carbon sources for growth. The description of Methanosaeta concilii, the type species, is based on type strain GP6 (= DSM 3671 = OGC 69 = NRC 2989 = ATCC 35969).