Abstract: | The batch growth curves of Laclobacillus delbreuckii exhibit several exponential phases. From the results of a series of shaker flask experiments, the position of the slope changes in the growth curve and the overall bacterial yield is affected by the initial amount of yeast extract in the medium. It is postulated that this behavior is due to several growth enhancing substances that are initially in the yeast extract and are consumed by the bacteria during the course of the fermentation. Using a Monod-type expression to represent the effect of growth enhancing components in a proposed growth rate expression, a mathematical model of the system is set up and solved on the analog computer. |