利用响应面法优化γ-聚谷氨酸发酵培养基

Optimization of fermentation medium for γ-PGA with response surface method

利用筛选出的枯草芽孢杆菌发酵生产γ-聚谷氨酸,并对其发酵培养基进行优化。首先采用逐因子试验法寻找出各因素的参考范围。在此基础上,利用Plackett-Burman试验筛选出显著影响γ-PGA产量的3个主要因素:酵母粉、谷氨酸钠和CaCl2。用最陡爬坡试验逼近最大产γ-PGA的区域。然后利用Box-Behnken试验对显著因素进行优化,得酵母粉、谷氨酸钠和CaCl2的最佳浓度分别为4.18g/L、76.89g/L和0.1422g/L。在优化后发酵培养基条件下,γ-PGA的产量达到了43.26g/L,比初始γ-PGA产量提高了1.035倍。

Production of γ-polyglutamic acid by fermentation with screened Bacillus subtilis and optimization of fermentation medium was studied. Reference ranges of each factor were firstly determined with single factorial experiment and three major factors significantly affected production of γ-PGA, which were yeast extracts, sodium glutamate and CaCl2 were determined by Plackett-Burman design. The optimum fermentation conditions were optimized with Box-Behnken experiment and the largest regional of γ-PGA production was approach with the steepest ascent experiment. The optimum composition of medium was addition of yeast extract, sodium glutamate and CaCl2 was 4.18g/L, 76.89g/L and 0.1422g/L, respectively. Under the optimum fermentation medium conditions, production of γ-PGA was 43.26g/L, increased 1.035 times to that of using initial medium.