MATHEMATICAL-MODELING OF INHIBITION-KINETICS IN ACETONE-BUTANOL FERMENTATION BY CLOSTRIDIUM-ACETOBUTYLICUM

Acetone-butanol fermentation by Clostridium acetobutylicum suffers from severe product inhibition effects. This paper presents the results of studies on the cell growth kinetics of the culture under the inhibition of multiple products/byproducts. The inhibition effects caused by multiple components simultaneously as well as a single product alone were examined. Fractional factorial experiments were conducted, and statistical analysis of the study results was performed. Acetate, butyrate, butanol, and pH a ere found to exhibit synergistic inhibitory effects on the cell growth of C. acetobutylicum. Ethanol and acetone alone or in the presence of other products did not show inhibitory effects under the experimental conditions. Among the various mathematical forms of equations that were evaluated, a parabolic form was found to; be most suitable for describing the overall synergistic inhibitory effects caused by acetate, butyrate, butanol, and pH. The simulation results achieved by using the model were promising.