短乳杆菌产葡萄糖异构酶培养基的响应面法优化

Media optimization studies for glucose isomerase production by Lactobacillus brevis using response surface methodology

【目的】优化产葡萄糖异构酶短乳杆菌（Lactobacillus brevis）培养基，提高短乳杆菌产葡萄糖异构酶的能力。【方法】采用基于非完全平衡块原理的Plackett-Burman法和响应面法（Response Surface Methodology，RSM），对短乳杆菌发酵产葡萄糖异构酶的培养基进行优化。【结果】①短乳杆菌产葡萄糖异构酶的3个主要影响因子为：木糖、玉米浆干粉和MgSO4·7H2O。②通过最陡爬坡试验、旋转中心组合设计及响应面分析确定的短乳杆菌最适发酵培养基组成为：木糖13．43g／L、玉米浆干粉23．14g／L、MgSO4·7H2O2．54g／L、MnSO4·4H2O 0.25g／L、酵母膏5g／L、醋酸钠5g／L、柠檬酸三铵2g／L、K2HPO4 2g／L、Tween-80 1mL／L、pH6．2～6．4。【结论】获得了能够提高短乳杆菌产葡萄糖异构酶能力的培养基，在优化培养基的条件下，葡萄糖异构酶总活力达到80.5U，较优化前的60.5U提高了33．06％．

[Objective] The study optimized the unitune media in order to improve glucose isomerase production by Lactobacillus brevis. [Method] Response Surface Methodology （RSM） was used to optimize the culture components for glucose isomerase production by Lactobacillus brevis. [Result] ①Ptackett-Burman Design was used to evaluate the process variables relevant to the production of glucose isomerase. MgSO4· 7H2O,eorn-steep powder and xylose with great influence on glucose isomerase were chosen. ②The path of steepest ascent was used to approach the optimal region of the glucose isomerase-producing medium subsequently. Finally, the concentrations of those three main factors were determined by Central Composite Rotatable Design and Response Surface Analysis. The optimized conditions were： xylose13.43 g/L, corn-steep powder 23.14 g/L,MgSO4 ·7H2O 2.54g/L,MnSO4 · 4H2O 0.25 g/L,yeast extact 5 g/L,natrium acetate 5 g/L,ammonium citrate 2 g/L,K2HPO4 2 g/L,Tween-80 1 mL/L, pH 6.2-6.4. [Conclusion] The medium which can improve glucose isomerase production by Lactobacillus brevis was obtained. The enzyme activity of glucose isomerase of Lactobacillus brevis increased from 60.5 to 80.5U,which was 33.06% higher than preliminary culture.