采用Plackett - Burman试验设计法及响应面分析法(RSM),对固定化Bacillus sp. ULi-11菌株生物不对称合成(R)-α-羟基苯乙酸((R)-HPA)进行优化. 首先采用Plackett - Burman试验设计筛选影响产率的主要因素,再用最陡爬坡方法逼近最大响应区域后用Box - Behnken试验设计及RSM进行回归分析,得到的最佳条件为温度33 ℃,增殖时间9.3 h,装液量18 mL,转速180 r/min,pH 7.2,接种量2%,种龄16 h,在此条件下(R)-HPA的产率为49.61%,比优化前的产率提高了23.7%. 图3 表6 参16
Plackett - Burman and response surface methodology were applied to optimize the asymmetric biosynthesis of (R)-α-hydroxyphenylacetic acid ((R)-HPA) with immobilized cells of Bacillus sp. ULi-11. Factors playing the important roles in the production of (R)-HPA were selected based on Plackett - Burman design. Then the path of steepest ascent was undertaken to approach the optimal region of the fermentation conditions. Finally, the optimal levels of those main factors were further optimized by using Box - Behnken and response surface analysis. The optimal conditions were temperature 33 ℃, proliferation time 9.3 h, liquid volume 18 mL, rotational speed 180 r/min, pH 7.2, inoculum amount 2%, seed age 16 h. Under the optimal conditions mentioned above, the yield of (R)-HPA reached 49.61%, which was increased by 23.7% compared with the value obtained before optimization. Fig 3, Tab 6, Ref 16