聚乙烯醇降解酶酶解聚乙烯醇最优条件研究

Optimal degradation conditions of a poly(vinyl alcohol)-degrading enzyme

为了提高聚乙烯醇(PVA)降解酶的催化降解能力,对假单胞菌Pseudomonas.sp XT11-Z90S产生的聚乙烯醇降解酶的降解条件进行了优化.同时,通过单因素实验研究了PVA浓度、温度、缓冲液pH对降解酶活性及PVA降解率的影响.最后,应用响应面分析方法对影响聚乙烯醇降解酶酶活的3个因素进一步优化.结果表明,单因素实验得出的适宜PVA浓度、温度、pH分别为1.0g·L-1、50℃、7.0.响应面分析法得出的最适的降解条件为:PVA浓度0.84g·L-1,温度53.5℃,pH值6.8.在最优条件下,PVA降解酶酶活达到了20.3U.mL-1,比优化前的12.2U.mL-1提高了66.4%.且6h后其降解率达到了52.6%.

The degradation conditions of a poly（vinyl alcohol）-degrading enzyme produced by strain Pseudomonas. sp XT11-Z90S were optimized in this study to improve the catalytic ability of the PVA-degrading enzyme. Single-factor experiments and response surface analysis were used to investigate the effects of the concentrations of poly（vinyl alcohol） （PVA）,temperature and pH on the activity of the enzyme and the degradation rate of PVA. And response surface analysis were constructed to further optimize 3 factors influence the activity of poly（vinyl alcohol）-degrading enzyme. The results showed that the appropriate concentrations of PVA,temperature and pH,determined by single-factor experiments,were 1.0g·L^-1,50℃ and 7.0,respectively. The optimal degradation conditions were：0.84 g·L^-1 PVA,53.5℃ and pH 6.8. Under the optimal conditions,the activity of the PVA-degrading enzyme was improved from 12.2 U·mL^-1 to 20.3 U·mL^-1,an increase of 66.4%. After 6 h,52.6% of the PVA was degraded.