粘红酵母苯丙氨酸解氨酶合成条件优化

首先利用Plackett-Burman设计及最陡爬坡试验对在摇瓶中对粘红酵母合成苯丙氨酸解氨酶的培养基和培养条件进行优化筛选,然后通过单因子试验确定最适诱导物。在此基础上,进行发酵罐葡萄糖浓度、产酶pH值以及诱导物添加时间的优化。结果显示优化的发酵培养条件为葡萄糖1g/L,蛋白胨35g/L,NaCl 5g/L,KH2PO4 0.25g/L,（NH4）2HPO4 1.5g/L;接种量4%;初始pH值为5;控制产酶pH值为7;诱导物为L-苯丙氨酸,分别在发酵8h和26h时添加;在上述优化条件下,最高比酶活为40.85U/g,比未优化前提高了7.3倍。

Optimization of phenylalanine ammonia lyase production conditions by Rhodotorula glutinis

The experiments were first performed in shaking flask to screen the medium and optimize the fermentation conditions of phenylalanine ammonia lyase production by Rhodotorula glutinis with Plackett-Burman design and the steepest ascent method,and the optimum inducer was screened with single-factor design.And on the basis of results,fermentation conditions of glucose concentration,pH value of phenylalanine ammonia lyase production and the time of adding inducer in fermenter were optimized.The optimum conditions were obtained as follows: glucose 1g/L,peptone 35g/L,NaCl 5g/L,KH2PO4 0.25g/L,(NH4)2HPO4 1.5g/L,inoculum 4%,initial pH value 5;fermentation pH was controlled at 7;and the optimum enzyme inducer was L-phenylalanine,which was added at the points of fermentation after 8h and 26h.Under these conditions,the specific enzyme activity reached 40.85 U/g,which was 7.3 fold higher than that of original condition.