Metabolic differences betweenEscherichia coli cultures growing aerobically and anaerobically in the presence of fluoroacetate

The amount of citrate and pyruvate increased during the stationary phase of anEscherichia coli B culture growing in a synthetic medium, aerobically in the presence of glucose. In an anaerobic culture the amount of citrate was minute and did not rise during the stationary phase; the level of pyruvate in the stationary phase rose only slightly. Fluoroacetate blocked the growth of cells both aerobically and anaerobically. Cultures growing aerobically in the presence of fluoroaeetate displayed an increased accumulation of citrate as compared with the control. In anaerobic cultures citrate did not accumulate in the presence of inhibitory concentrations of fluoroacetate. In the presence of 2mm fluoroacetate cells grew aerobically somewhat more slowly at first, then inhibition ceased and finally the growth yield was greater than in the control. The obtained data indicate that citrate accumulated at first was partly utilized for growth under these conditions. The results are discussed from the point of view of differences in the metabolism of aerobically and anaerobically grown cells.