APPLICATIONS OF COMPUTERS TO THE INDIRECT MEASUREMENT OF BIOMASS CONCENTRATION AND GROWTH RATE BY COMPONENT BALANCING

Abstract

The true advantage to the interfacing of computers to fermentation processes is the dynamic optimization of the fermentation using model reference control techniques. This has not been realized and is due in part to the absence of accurate realtime process variable data such a biomass concentration and growth rate.Real-time techniques employing an on-line computer were evaluated to estimate biomass concentration and growth rate data by material balancing oxygen using the yield and maintenance model. The results of this analysis were satisfactory for 2 metabolically simple fermentations. However, in order to obtain estimates of equivalent accuracy for a metabolically complex fermentation (aerobic growth of Baker's yeast), it was necessary to correct values of Y. and My for metabolic variations by introducing a x/0 metabolic correction function, B Z/X which is a function of respiratory quotient.