响应面法优化玉米秸秆酶水解条件的研究

针对玉米秸秆制取燃料乙醇过程中玉米秸秆酶水解效率低的问题,利用响应面法对玉米秸秆酶水解条件进行优化。首先通过两水平Plackett-Burman试验中8个因素,筛选出3个对还原糖产率影响最大的因素(酶浓度、温度和固液比),再通过最陡爬坡试验确定其最优区域,然后通过Box-Behnken设计和响应面法进一步确定因素间相互关系和以还原糖最大产率为目标的最优条件。结果表明:酶浓度和固液比、温度和固液比间的交互作用对酶水解的影响显著,还原糖最大产率(42.97%)的最优条件为酶浓度55.45U.g-1,酶比例2∶1,温度44.39℃,pH值5.0,固液比1∶10.3,转速140r.min-1,酶解时间72h,Mg2+浓度0.01%。

Optimization of Enzymatic Hydrolysis of Corn Stover Using Response Surface Methodology

In order to solve the low enzymatic hydrolysis efficiency of corn stover in the process of making ethanol,response surface methodology was applied for optimization.Fristly as identified by a two-level Plackett-Burman design with 8 variables,three important factors(enzyme concentration,temperature,and solid-liquid ratio) influencing reducing sugar yield were selected.Steepest ascent method was undertaken to determine their optimal regions.Box-Behnken design and response surface analysis were adopted to further investigate the mutual interactions between these variables and to identify their optimal values that would produce maximum reducing sugar.The analysis results indicated that interactions between enzyme concentration and solid-liquid ratio,temperature and solid-liquid ratio affected the enzymatic hydrolysis significantly.The predicted results showed that the maximum reducing sugar yield(42.97%) could be obtained under the optimum conditions of enzyme concentration 55.45U·g-1,enzyme ratio 2:1,temperature 44.39℃,pH value 5.0,solid-liquid ratio 1:10.3,speed 140r·min-1,hydrolysis time 72h,Mg2+ concentration 0.01%.