Two useful dimensionless parameters that combine physiological, operational and bioreactor design parameters for improved control of dissolved oxygen

Two new dimensionless parameters (Φ and Ω) are proposed for calculating the proportional, integral, and derivative constants of a dissolved oxygen proportional integral-derivative (PID) feed-back control algorithm from knowledge of the growth rate, bioreactor design and operation variables. The values of Φ and Ω were determined for a broad range of Reynolds numbers (between 1000 to 40 000) during the exponential growth phase of two highly different processes: fermentations of recombinant Escherichia coli and cultures of human hematopoietic cells. The utility of Φ and Ω for use in dissolved oxygen self-tunning adaptive control algorithms is discussed.[PUBLICATION ABSTRACT]