响应面法优化枯草芽孢杆菌产γ-PGA的条件

Optimization of γ-PGA fermentation condition with Bacillus subtilis by response surface methodology

对枯草芽孢杆菌液体发酵产γ-聚谷氨酸[γ-poly(glutamic acid),γ-PGA]条件进行了优化。首先采用单因子实验筛选出最适碳源为玉米糖化液,氮源为蛋白胨和谷氨酸钠,无机盐为KH2PO4,MgCl,MnCl2和NaCl。在此基础上,利用Plackett-Burman设计对影响产量的12个因素进行评价,筛选出具有显著效应的因素蛋白胨、谷氨酸钠和NaCl。用最陡爬坡路径逼近最大产γ-PGA区域后,利用响应面中心组合设计对显著因素进行优化,得出蛋白胨、谷氨酸钠和NaCl的最佳质量分数分别为0.54%,8.13%和0.96%。优化后液体发酵液γ-PGA产量提高到29.00 g/L,比初始γ-PGA产量14.10 g/L提高了2倍。

The fermentation condition of γ-poly （ glutamic acid） （γ-PGA） by Bacillus subtilis was optimized. Using single factorial experiments, sources of carbon, nitrogen and inorganic ions were determined as corn flour saccharification liquor, peptone, glutamate, KH2PO4, MgCl2, MnCl2, and NaCl. Three significant factors, peptone, glutamate and NaCl, were screened by Plackett-Burman design. The optimal region of γ-PGA production was found by steepest ascent approach. The optimal combined concentration for maximum γ-PGA production was determined by response surface methodology as： 0.54% Peptone,8.13% Glutamate and 0.96% NaCl. The production level was increase to 14. 10 g/L.