OXIDATIVE ASSIMILATION BY BACILLUS MEGATERIUM

Clifton, C. E. (Stanford University, Stanford, Calif.). Oxidative assimilation by Bacillus megaterium. J. Bacteriol. 85:1365-1370. 1963.-Washed suspensions of Bacillus megaterium oxidized to CO(2) about 39% of the U-C(14)-glucose supplied and incorporated about 37% of the label by the time a marked break in the rate of O(2) consumption was noted. Almost one-half of the label was lost from the cells on acidification of the suspension. The remainder of the C(14) was present in the supernatant fluid, primarily in forms as yet unidentified, but other than carbohydrate. Both the Embden-Meyerhof and hexose monophosphate pathways of oxidation were involved. Endogenous respiration appeared to be inhibited only to a slight extent in the presence of an exogenous substrate. C(14) appeared in all fractions of the cells; the highest percentage of firmly bound C(14) was present in hot 5% trichloroacetic acid-insoluble matter. A decrease in C(14) content of the various fractions was noted during endogenous respiration of cells labeled during growth. Pyruvate and acetate were oxidized very slowly by B. megaterium. The results indicate the complexity of oxidative assimilation and the dynamic state of cellular metabolism.