酒糟纤维素超声波辅助酶解工艺研究

为促进我国酒糟资源的高值化开发和利用，本论文探究了基于超声波预处理的酒糟纤维素酶解工艺条件。首先通过单因素实验研究了超声工作参数（时间、温度、功率）及酶解工艺参数（时间、pH、温度、酶添加量、底物浓度）对酒糟纤维素酶解效果影响，在此基础之上进行了Plackett-Burman试验筛选出影响酶解反应的关键因素，再采用Box-Behnken试验对酶解工艺进行优化。Plackett-Burman试验结果表明，影响酒糟纤维素酶解的关键因素为:超声时间、酶解时间、酶解pH、酶添加量。Box-Behnken旋转中心组合试验优化得出最佳酶解工艺条件为:超声时间21 min、酶解时间140 min、酶解pH5.41、酶添加量990 U/g、超声温度60 ℃、超声功率200 W、酶解温度50 ℃、酶解底物浓度1:20 g/mL，在此条件下酒糟纤维素转化率为5.62%，较对照组（未经超声波处理）提高了35.4%，表明超声波预处理是提高酒糟纤维转化率的有效途径。

Study on Ultrasonic-Assisted Enzymatic Hydrolysis of Distiller’s Grains Cellulose

In order to promote the development and utilization of distiller’s grain resources in China, the present study explored the enzymatic hydrolysis conditions of distiller’s grains cellulose based on ultrasonic pretreatment. Firstly, the effects of ultrasound parameters (time, temperature, power) and enzymatic hydrolysis process parameters (time, pH, temperature, enzyme addition, substrate concentration) on the enzymatic hydrolysis of vinasse cellulose were studied through single-factor experiments. The Plackett-Burman test was carried out to screen out the key factors which affected the enzymatic hydrolysis reaction, and then the Box-Behnken test was used to optimize the enzymatic hydrolysis process. The Plackett-Burman test results showed that the key factors affecting the enzymatic hydrolysis of vinasse cellulose were ultrasound time, enzymatic hydrolysis time, enzymatic hydrolysis pH, and enzyme addition. The Box-Behnken results showed that the optimal enzymolysis process conditions were ultrasonic time 21 min, enzymolysis time 140 min, enzymatic hydrolysis pH5.41, enzyme addition 990 U/g, ultrasonic temperature 60 ℃, ultrasonic power 200 W, enzymolysis temperature 50 ℃, and the concentration of enzymatic hydrolysis substrate 1:20 g/mL. Under these conditions, the cellulose conversion rate of distiller’s grains were 5.62%, which was 35.4% higher than that of the control group. The results showed that ultrasonic pretreatment was an effective way to improve the cellulose conversion rate of distiller’s grains.