Pseudomonas MS can grow on methylamine and a number of other compounds containing Cl units as a sole source of carbon and energy. Assimilation of carbon into cell material occurs via the "serine pathway" since enzymes of this pathway are induced after growth on methylamine, but not malate or acetate. A mutant has been isolated which is unable to grow on methylamine or any other related substrate providing Cl units. This mutant is also unable to grow on acetate. Measurment of enzyme activities

more »

... cell-free extracts of wild-type cells showed that growth on methylamine caused induction of isocitrate lyase, a key enzyme in the glyoxylate cycle. The mutant organism lacks malate lyase, a key enzyme of the serine pathway, and isocitrate lyase as well. These results suggest that utilization of Cl units by Pseudomonas MS results in the net accumulation of acetate which is then assimilated into cell material via the glyoxylate cycle. Pseudomonas MS was isolated from soil by enrichment culture on trimethylsulfonium chloride (C. Wagner, Bacteriol. Proc., p. 91, 1964). The organism will also grow on methylamine, dimethylamine, trimethylamine, a number of sugars, and various C2, C" and C, compounds (8). With respect to the types of reduced C,