Process optimization of ethanol fermentation on maize straw enzymatic saccharification liquid

In this paper,the advanced mix-yeast was chosen out from four groups of mixed yeasts,it was used in the process optimization of ethanol fermentation on maize straw enzymatic saccharification liquid.The test results showed the mixed yeasts composed by P.tannophilus and S.cerevisiae had the hightest ethanol fermentation capacity.After 60 hours fermentation the highest ethanol concentration was 12.55 g/L,corresponding to 68.63% of theoretical ethanol yield.According to the result of quadratic regression combinatorial design,fermentation temperature was 28.0 ℃,initial pH value was 5.2,inoculum amount was 8.1%,under these conditions,the actual ethanol concentration was 13.03 g/L,the ethanol yield was 0.36 g ethanol/g sugar,corresponding to 70.59% of theoretical ethanol yield,which was almost conform with the predictive value of regression equation.