响应面分析法优化α-环糊精的酶转化工艺

Optimization of Conversion Process of α-Cyclodextrin with Enzyme Using Response Surface Methodology

为获得较高的α-环糊精转化产率,采用单因素实验和响应面实验方法,筛选底物种类、底物浓度、加酶量、酶作用时间、作用温度和pH等多个单因素,对海洋芽孢杆菌Y112产的α-环糊精葡萄糖基转移酶产α-环糊精的条件进行了优化。然后利用Plackett-Burman实验筛选得到影响α-环糊精转化率的3个主要因素:底物浓度、温度和pH值。最终采用响应面分析法得到的最佳转化条件为马铃薯淀粉浓度为5%,加酶量200 U/g(淀粉),pH值为8.4,温度30℃,200 r/min反应6 h,α-环糊精转化率均值为28.67%,比优化前的产率提高了2.48倍。

In order to obtain a higher yield ofα-cyclodextrin conversion,we use a single factor experiment and response surface experiment method,to optimize the production ofα-cyclodextrin conditions byα-cyclodextrin glucosyltransferase.The enzyme is derived from strain Y112.First,the single factor method was used to screen six factors including substrate species,substrate concentration,enzyme content,reaction time,temperature,and pH.Second,these main variables affecting the conversion ofα-cyclodextrin were evaluated with the Plackett-Burman test.The results suggested that substrate concentration,temperature,and pH were the most impactful factors.Finally,the optimal levels of the three factors were determined with central composite design and Design-Expert 8.05 software.The optimum conversion conditions were shown as follows:the concentration of potato starch was 5%,the amount of enzyme 200 U/g(starch),pH 8.4,200 r/min,reacted at 30℃for 6 h.Under the optimized conditions,the average value ofα-CD conversion was 28.67%,which was an increase of 2.48 times compared with the pre-optimization yield.