Influence of Glucose and Dissolved Oxygen Concentrations on Yields of Escherichia coli b in Dialysis Culture

Yields of Escherichia coli B grown on glucose were determined in dialysis and non-dialysis culture. The molar growth yields were compared under conditions of excess glucose and oxygen as well as glucose- and oxygen-limiting conditions. The molar growth yields on glucose (Y G) were determined for different periods during growth in non-dialysis cultures. A rapid decrease of Y G was observed and growth ceased even in the presence of high concentrations of glucose and dissolved oxygen in the culture liquid. The decrease in Y G was delayed in dialysis cultures where a high Y G could be maintained at very high cell concentrations. The inhibition of growth depended on the accumulation of end-products of fermentative degradation of glucose. These products interfered with the oxidative phosphorylation. A large proportion of the glucose was fermented even in the presence of high concentrations of dissolved oxygen in the culture liquid. A decrease in the growth yield per g glucose was also observed.