玉米秸秆同步糖化发酵产乙醇优化实验研究

STUDY ON OPTIMIZATION OF SIMULTANEOUS SACCHARIFICATION FERMENTATION FOR ETHANOL PRODUCTION FROM CORN STOVER

以耐高温酿酒酵母为对象,研究高温酿酒酵母利用玉米秸秆为原料同步糖化产氢乙醇的影响因素,采用Plackett-Burman(PB)法对影响乙醇产率的5个因素进行筛选,采用CCD模型及响应面分析对影响因素进行优化设计,确定高温酿酒酵母利用玉米秸秆为原料同步糖化产氢乙醇的最佳工艺条件。研究结果表明:高温酿酒酵母利用玉米秸秆酶解液同步糖化产乙醇过程中接种量、温度、酶浓度和发酵时间4个因素对乙醇产量的影响最为明显,温度和发酵时间的交互作用最为显著。利用优化设计得到的最佳产乙醇工艺为:接种量7.4%、温度34.2℃、初始p H值5.0、酶浓度49.36 U/g。在此条件下,发酵105.12 h后乙醇产率可达59.88%,实验结果与响应面拟合方程的预测值(60.85%)吻合良好。

In order to obtain the optimal condition of simultaneous saccharification and fermentation from corn straw for ethanol production, Plackett-Burman experiment design is employed to screen the significant factors affecting the ethanol yield, which include inoculums, temperature, enzyme concentration and fermentation time. The results of CCD experiment and response surface analysis showed that interaction between temperature and fermentation time affected the fermentation significantly. Under the optimal conditions given by response surface analysis： inoculums 7.4%, temperature 34.2 ℃, initial pH value 5.0 and enzyme concentration 49.36 U/g, the measured average ethanol yield reach to 59.88%, after 105.12 h fermentation, which is consistent well with the predicted value （60.85%）.