Abstract
Mah (Curr. Microbiol. 3:321--326, 1980) isolated Methanococcus mazei, a methanogen that was first described by Barker in 1936. The current characterization of this organism demands transfer of it to the genus Methanosarcina. We present an emended description of Methanosarcina mazei comb. nov. Since Methanococcus mazei (Approved Lists 1980) is the type species of the genus Methanococcus and its removal invalidates the genus, we request an Opinion from the Judicial Commission to remove the type species from the genus Methanococcus and to conserve this genus with Methanococcus vannielii as the type species, as suggested by Balch et al. (Microbiol. Rev. 43:260--296, 1979).