Kinetic Studies on Alcoholic Fermentation Under Substrate Inhibition Conditions Using a Bioreactor with Stirred Bed of Immobilized Yeast Cells

Abstract

The studies on the alcoholic fermentation with immobilized S. cerevisiae cells on alginate using a bioreactor with stirred beds of biocatalysts indicated that the diffusion inside the biocatalyst particles attenuates or avoids the inhibitory effects, preserving the microbial activity. Using a mathematical model adequate for ethanol formation in heterogeneous systems the kinetic parameters V, KI and K’M have been estimated. Therefore, the obtained values of V and K’M were found to be higher than those corresponding to the homogeneous media under ethanol inhibition, but lower than those for homogeneous media without inhibitory fenomena.