INFLUENCE OF GROWTH MEDIUM ON ASSIMILATORY ACTIVITIES OF ESCHERICHIA COLI

Abstract

Clifton, C. E. (Stanford University, Stanford, Calif.). Influence of growth medium on assimilatory activities of Escherichia coli. J. Bacteriol. 85:1371-1377. 1963.-Nutrient agargrown cells assimilate about 50% of the glucose added to washed suspensions (phosphate buffer, pH 7.2, 30 C), as indicated by O(2) consumption or C(14)-uptake from uniformly labeled glucose. Most of the nonassimilated glucose is oxidized, but a small portion remains in forms other than glucose in the suspension medium. Cells from glucose agar, however, assimilate only about 20 to 30% of the U-glucose and ferment a considerable portion of the remainder, the extent of each being determined in part at least by growth conditions. Evidence is presented that this behavior is the result of metabolic controls induced during growth. C(14) from U-glucose appeared in all fractions of either agar- or glucose agar-grown cells, the highest percentage being present in cellular matter insoluble in hot 5% trichloroacetic acid. Data on the distribution of C(14) from 1-, 2-, and 6-glucose, and from acetate and pyruvate, are also presented.