Microbiological and Biochemical Studies towards Optimization of Substrate Utilization by Methanogenic Bacteria. Final Report December 1982-February 1986

摘要

The microbiology of acetate conversion was studied. New acetotrophic and methylotrophic isolates were characterized. Biotin, Fe, Co and Ni were shown to be required for growth on methylotrophic substrates. A novel technique was developed for the large-scale culture of acetotrophs. The pathway of acetate conversion to methane and carbon dioxide was studied. It was shown that the methyl group of acetate was transferred to coenzyme M. The levels of an enzyme system that demethylates methyl coenzyme M and requires carbon monoxide was correlated with growth on acetate which implicates this system in the pathway of acetate to methane. However, free carbon monoxide was shown not to be an intermediate in the pathway which suggests a reduced Cl intermediate is formed from the carboxyl group of acetate. The carbon monoxide dehydrogenase was purified and characterized. In the presence of cyanide, epr signals from the iron-sulfur and flavin centers are unmasked which allows further study of the epr properties of these centers to elucidate the mechanism of action of the enzyme.