OXIDATIVE ASSIMILATION BY BACILLUS MEGATERIUM

Abstract

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.