title: Source of carbon and hydrogen in methane produced from formate by Methanococcus thermolithotrophicus.
abstract: Methanococcus thermolithotrophicus is able to produce methane either from H2-CO2 or from formate. The route of formate entry into the methanogenic pathway was investigated by using 2H2O or [13C]formate and analysis by mass spectrometry. When cells (H2-CO2 or formate grown) were transferred to formate medium in 95% 2H water, the proportion of 2H in methane was 95%. When cells (H2-CO2 or formate grown) were transferred to media containing [13C]formate in the presence of H2-CO2 or He-CO2, the ratio of 13CH4 to 12CH4 increased over time parallel to the ratio of 13CO2 to 12CO2. The cells catalyzed a significant exchange of label between [13C]formate and 13CO2.
mesh_terms: D002244:Carbon / Q000378:metabolism*; D003903:Deuterium / Q000378:metabolism; D019605:Euryarchaeota / Q000378:metabolism*; D005561:Formates / Q000378:metabolism*; D006859:Hydrogen / Q000378:metabolism*; D008697:Methane / Q000096:biosynthesis*; D010084:Oxidation-Reduction
chemical_list: D005561:Formates; C030544:formic acid; D002244:Carbon; D006859:Hydrogen; D003903:Deuterium; D008697:Methane