DOUBLE-SUBSTRATE-LIMITED GROWTH OF ESCHERICHIA-COLI

Fairly detailed computer models have been developed to simulate the growth of Escherichia coli under both glucose and ammonium ion growth limitations. Such models could potentially predict growth rates under conditions where both glucose and ammonium ion concentrations affected the growth rate. However, the computer model is relatively complex and simple rate forms that can predict the cell growth rate under double-substrate limitations are desirable. A key requirement for effective use is that growth on both substrates should be predicted from independent data sets where only a single substrate is limiting. Three types could be considered. The purposes of this communication are to present data indicating that a region of double-substrate may exist, to validate the computer model for double-substrate-limited growth, and to select among the three rate forms the rate form most closely describing reality for this specific system.