SIMULATION AND EXPERIMENTAL STUDIES OF THE PROFILE CONTROL OF THE SPECIFIC GROWTH RATE IN A FED-BATCH CULTURE

Abstract The aim of this paper is to develop and discuss a practically useful system so that the specific growth rate in a baker's yeast fed-batch cultute will follow the desired profile specified in advance as accurately as possible. For this, first, the specific growth rate should be estimated using indirect measurement of the overall growth rate or using online data of cell concentration. Based on the careful analysis of the previously proposed method, an improved method was proposed which uses moving averages and dynamic mass balancing. It was shown that the specific growth rate could be estimated with sufficient accuracy using an extended Kalman filtering algorithm using the estimated overall growth rate, or using the cell concentration. Secondly, the control scheme called "Prograrruned-controller/Feedback-compensator(PF) system " consists of a prograrruned controller and a feedback compensator has been used for the profile control of μ. The PF-MRAC in which the model reference adaptive controller was used for the compensator, was shown to be effective for this purpose. Finally, the profile control of the specific growth rate in a baker's yeast fed-batch culture was realized experimentally using the proposed control scheme. The experiments showed that the estimation and control schemes proposed were sufficiently useful.