Growth of E. Coli W to high cell concentration by oxygen level linked control of carbon source concentration

The growth of E. coli W in a bench scale fermentor to high cell concentration is described. The method involves growth‐linked introduction of ammonia to the culture, sparging the culture with oxygen, and maintenance of aerobic conditions during the final growth phase by gradually and automatically decreasing the concentration of the carbon source, sucrose, in the culture. Thus, the oxygen demand is kept within the limits of the supply capacity, and a linear growth rate during the final phase of growth is obtained. A concentration of 42 g dry cell per liter was obtained. The yield constants for nitrogen and phosphorous were determined and were compared with those obtained using the temperature variation method.