INHIBITORY EFFECT OF ETHANOL ON ETHANOL FERMENTATION

Abstract

Anaerobic growth of Saccharomyces carlsbergensis LAM 1068 was inhibited completely at the ethanol concentration of P_mg=95g/l. However, carbon dioxide still produced in a Warburg flask at the ethanol concentration higher than 95g/l. The minimum ethanol concentration for complete inhibition of fermentation was P_mf=195g/l. Based on this experimental observation a new kinetic equation is presented, in which the inhibitory effect of ethanol concentration (P) on the specific fermentation rate (q) is evaluated separately at both ranges of ethanol concentration. q/q₀=a(1-P/P_mg)+b(1-P/P_mf) The above equation closely represented the experimental results. Comparison with the several kinetic models in the literature is discussed.