When Methanosarcina barkeri is grown on methanol as the sole carbon source, a B12-containing protein is synthesized by this organism. This B12 protein contains bound aquocobalamin, and when this cofactor is reduced and methylated with [14C]methyl iodide, the resultant [14C]methyl B12 protein is extremely active in the biosynthesis of 14C-labeled methane. These findings indicate that a B12-dependent system is operative in the biological formation of methane in addition to other systems that are B12-independent.
0036-8075 (Print)0036-8075 (Linking)Journal ArticleResearch Support, U.S. Gov't, Non-P.H.S.Research Support, U.S. Gov't, P.H.S.