Methanosarcina frisia

Sequence Comparison Between the N-Terminal Part of the Fepr Genes from Desulfovibrio desulfuricans (Dd) and Desulfovibrio vulgaris (Dv), Carbon Monoxide Dehydrogenase from Methanothrix soehngenii (Ms), Methanosarcina frisia Gdl (Mf), Clostridium thermoaceticum (Ct), Rhodospirillum rubrum (Rr), and Anaerobic Ribonucleotide Reductase from Escherichia coli (Ec) ... 

Halobacterium salinarium Methanosarcina frisia Sulfolobus acidocaldarius Sulfolobus solfataricus... 

Rigid cell walls are absent in some species, for instance in Methanosarcina frisia [62] and in Methanosarcina acetivorans [63], which exhibit only a proteinaceous S-layer outside the cytoplasmic membrane, although both species are closely related to other members of Methanosarcina on the basis of several metabolic and molecular characteristics. 

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