Optimization of Ethanol Production by Thermotolerant and High Alcohol-producing Yeast Using Response Surface Analysis*

Abstract

According to 23 Fractional Factorial,fermentation temperature,inoculum size and initial glucose concentration were screened out for self-study variables which affected the yield of ethanol and biomass of yeast after 9 h fermentation,and then optimized by Box-Behnken factorial design of response surface methodology in shake flask.The optimal conditions of ethanol fermentation were that: Fermentation temperature was 36.9 ℃,initial fermentable sugar concentration 280 g/L,inoculum size 9.4%,and final ethanol concentration 131.0 g/L.According to verification experiment,the ethanol yield of 129.9 g/L was obtained within 48 hours when the yeast fermentation temperature of 37 ℃,the initial sugar concentration of 280 g/L,and inoculum size of 9.4%,which indicated that the model was reliable and effective.Fig 2,Tab 3,Ref 13