Metabolic Features of Methane‐ and Methanol‐Utilizing Bacteria

  • 1 January 1983
    • journal article
    • Published by Wiley
Abstract
Investigations of a wide range of methane‐ and methanol‐utilizers showed a striking versatility of their metabolism dependent on the genotype and growth conditions. A correlation between pathways of carbon and nitrogen metabolism was found. It was most stringent in obligate methane‐utilizers: the hexulosephosphate pathway bacteria assimilated NH3 by the reductive amination of α‐ketoglutarate or pyruvate whereas the serine pathway bacteria used the glutamate cycle (glutamine synthetase + glutamate‐oxoglutarate aminotransferase).Multiple enzymic lesions were found in central metabolism of obligate methylotrophs, i.e. the absence of the enzymes of glycolytic and pentosephosphate pathways, gluconeogenesis, citric acid cycle and glyoxylate shunt. These metabolic blocks were not so profound and could be compensated in restricted and facultative methylotrophs during heterotrophic growth.The average levels of exogenous CO2 fixation in methylotrophic bacteria with the hexulosephosphate, serine and ribulosebisphosphate pathways were found to be 10, 30 and 80% of their total cell carbon, respectively.These results served as a basis for biotechnological applications of metabolic potential of methylotrophs (production of biomass, polysaccharides and enzymes as well as for microbiological treatment of industrial waters containing toxic C1‐ and Cn‐compounds).