INVIVO NUCLEAR-MAGNETIC-RESONANCE STUDIES OF THE METABOLISM OF METHANOL AND PYRUVATE BY METHANOSARCINA-BARKERI

The metabolism of methanol and pyruvate by cells of Methanosarcina barkeri was probed invivo by NMR taking advantage of the non-invasive characteristics of this technique. Upon administration of substrates, the kinetics of substrate consumption, the product formation and the energetic state of the cells was monitored using carbon-13, phosphorus-31 or proton NMR. The effects of several inhibitors and uncouplers were investigated. Cells supplied with pyruvate developed considerable levels of nucleotide triphosphate; methane production was monitored, as well as CO2 and H-2 formation. Most of the pyruvate was utilized for the synthesis of valine or intermediates of the valine pathway. The origin of the carbon atom in methane was elucidated using C-13-labelled pyruvate.