MATHEMATICAL-DESCRIPTION OF ETHANOL FERMENTATION BY IMMOBILIZED SACCHAROMYCES-CEREVISIAE

Fermentation characteristics of Saccharomyces cerevisiae ATCC 9763 imm obilised in Ca-alginate gel beads have been investigated in a stirred batch system at 2, 4, 8, 10% (w/v) initial glucose concentrations. The experimental results were tested using eleven different kinetic model s relating biomass and ethanol production and glucose utilisation in d ifferent forms. The models proposed by Monod and Hinshelwood were foun d to be more appropriate for describing the batch growth and ethanol p roduction of immobilised S. cerevisiae at low (2-4%) and high (8-10%) initial glucose concentrations, respectively. The validation of the mo dels chosen was done using data obtained from experiments in an inclin ed reactor with nutrient recirculation. (C) 1998 Elsevier Science Ltd. All rights reserved.