Metabolic Pathways in Methanococcus jannaschii and Other Methanogenic Bacteria

摘要: Eleven strains of methanogenic bacteria were divided into two groups on the basis directionality (oxidative or reductive) their citric acid pathways. These pathways readily identified for most methanogens from patterns carbon atom labeling in glutamate, following growth presence [2-13C]acetate. All used noncyclic pathways, but members family Methanosarcinaceae only found to use oxidative direction. Methanococcus jannaschii failed incorporate acetate despite transmembrane equilibration comparable other weak acids. This organism was devoid detectable activities acetate-incorporating enzymes acetyl coenzyme A synthetase, kinase, and phosphotransacetylase. However, incorporation [1-13C]-, [2-13C]-, [3-13C]pyruvate during M. possible resulted indicative a pathway operating reductive direction synthesize amino Carbohydrates labeled consistent with glucogenesis pyruvate. Leucine, isoleucine, phenylalanine, lysine, formate, glycerol, mevalonate incorporated when supplied medium. Lysine preferentially lipid fraction, suggesting role as phytanyl chain precursor.