Formation of trideuteromethane from deuterated trimethylamine or methylamine by Methanosarcina barkeri

Methanosarcina barkeri was grown on trimethylamine, methylamine, or methanol containing completely deuterated methyl groups. Methane was collected and analyzed in a mass spectrometer. It contained 79 to 83% CD3H and 14 to 18% CD2H2. This demonstrated that the methyl groups of the above compounds served primarily as direct precursors of methane.