Modeling the growth of Corynebacterium glutamicum under product inhibition in l-glutamic acid fermentation

In the fermentation of l-glutamic acid by Corynebacterium glutamicum, the growth inhibition by the substrate (glucose) at higher concentrations, and by the product at almost all concentrations seem to occur. In order to identify the range of concentrations for substrate limitation/inhibition, the experiments were conducted separately with different initial glucose concentrations. Proof of growth inhibition by the product was established by analyzing the data obtained from the time course of batch fermentation. Based on the experimental observations, a product inhibition model has been developed by modifying the Monod's kinetic equation for cell growth. This model simulates the growth satisfactorily. The same model is also able to describe the experimental data for growth of C. glutamicum obtained from different investigators.