[Batch cultures of Escherichia coli with added substrate under various aeration conditions]

The growth parameters (Xmax, Y, mu) of Escherichia coli batch cultures were studied when a substrate was added under different aeration conditions. If the pH was not adjusted, the bacterial growth stopped at pH 4.5 under the aerobic conditions or at pH 5.8 under the anaerobic conditions. When the pH 7.0 was constantly maintained, the accumulation of acid products in the aerobic culture was 3 times as high as in the anaerobic culture by the time the growth ceased. The anaerobic culture resumed its growth upon aeration. A hypothesis is proposed to explain the data.