[Oxidation and assimilation pathways of methylated amines in Arthrobacter globiformis]

The oxidation by Arthrobacter globiformis B-175 of tertiary, secondary, and primary amines is catalyzed by specific induced enzymes. Trimethylamine is oxidized to dimethylamine via trimethylamine N-oxide by monooxygenase and demethylase. Dimethylamine is converted to methylamine by another monooxygenase. Methylamine is oxidized to ammonia and formaldehyde by aminoxidase. Formaldehyde is assimilated via ribulose monophosphate cycle, which is confirmed by the presence of hexose-phosphate synthase and by the early and predominant formation of radioactive sugar phosphates during short-term incubation of the cells with labelled methylated amines. Hexose-phosphate synthase was also found in two other strains of A. globiforms (B-126, B-53) which assimilated methylated amines. This methylotroph contains the enzymes of the Krebs cycle which seems to be involved in the synthesis of organic acids. The participation of ammonium nitrogen in anabolic processes is accomplished by reductive amination of alpha-ketoglutarate, glyoxylate, and pyruvate.