Kinetics of Batch Fermentations for Ethanol Production with Immobilized Saccharomyces cerevisiae Growing on Sweet Sorghum Stalk Juice

The effect of different initial reducing sugar concentration on ethanol production in batch fermentation of Chuntian No. 2 sweet sorghum cultivar stalk juice by immobilized Saccharomyces cerevisiae CICC 1308 was investigated. In addition, kinetic model was studied. With the increase of initial sugar concentration, a significant inhibition on the maximum specific growth rate was clearly observed, however, there was no significant influence on the maximum specific ethanol production rate. Hinshelwood model was successfully applied to describe the effects of different initial reducing sugar concentration on the kinetic parameters of ethanol fermentation by immobilized Saccharomyces cerevisiae CICC 1308, using sweet sorghum stalk juice as the substrate.The kinetic parameters of fermentation process were obtained. The experimental results showed that Hinshelwood model could describe very well the dynamics of ethanol fermentation with immobilized Saccharomyces cerevisiae growing on sweet sorghum stalk juice containing initial reducing sugar concentration of 85–156 g/L.