Method for obtaining an empirical microbial growth model via chemostat operation

The fermentation of microorganisms is an important process in the biotechnology industry for the production of biological products. Development of a suitable model for the specific growth rate is critical for determining optimal operation of fermentation process. Since the value of the specific microbial growth rate equals the value of the known dilution rate during continuous fermentation, in this study, a methodology for obtaining an empirical microbial growth model via chemostat operation is proposed. A response surface methodology is proposed to obtain this empirical model with the highest accuracy at the optimal operating region of the process. This obtained model can be used to predict the operating conditions for achieving the optimal productivity during continuous fermentation. Furthermore, this model can also be used to design the overall feedforward–feedback control strategy of a fed-batch bioprocess and obtain great control performance despite various disturbances. Two processes with one simulated and another one by experiment were used to demonstrate the usefulness of the proposed methodology.