纳豆芽孢杆菌(Bacillus natto)发酵生产γ-聚谷氨酸过程中培养基组分的优化

The Optimization Research of Fermentation Medium of γ-Polyglutamic Acid(γ-PGA) Produced by Bacillus natto

通过摇瓶培养的方法,对纳豆芽孢杆菌(Bacillus natto)ZW-2发酵生产γ-聚谷氨酸过程中的培养基组分进行优化,从而提高γ-聚谷氨酸的产量。在单因素试验优化的基础上,利用DesignExport软件,采用Plackett-Burman试验设计筛选培养基组分中对产γ-聚谷氨酸影响最显著的因子,然后通过爬坡实验逼近γ-聚谷氨酸产量的最大区域,最后运用三因素三水平的Box-Behnken Design实验设计对关键因子进一步优化求得产γ-聚谷氨酸的最佳条件.结果表明,获得最佳产量时关键因子的最优组合为:谷氨酸钠(68.76g/L)、氯化铵(1.16g/L)和磷酸氢(二钾(2.16g/L),在此条件下,6组验证试验的平均产量为36.421g/L,是优化前的1.54倍。纳豆芽孢杆菌(Bacillus natto)ZW-2发酵生产γ-聚谷氨酸培养基组分的优化过程中,采用Plackett-Burman Design和Box-Behnken Design相结合的方法,效果显著,经济有效。

Optimization of fermentation medium for Bacillus natto ZW-2 to produce ~/ - polyglutamic acid （y-PGA） was studied to increase the yield of ^-polyglutamic with the shaking-flask culture. With Design-Export software, Plaekett-Burman Design was used to evaluate the effect of the factors on Bacillus natto ZW-2 to produce ^-PGA based on single-factor optimization experiment. Then steepest ascent experiments was designed to approach the maximum production area of ＂,/-PGA. At last, Box-Behnken experiment was used to get the optimal fermentation medium. The results showed that the optimal composition was sodium glutamate 68.76g/L, NH4Cll. 16g/L, K2HPO42.16g/L. On this condition the average yield of the verifying experiment was 36.421g/L, which was 1.54 times the original medium. Plackett-Burman design and Box-Behnken Design were simultaneously used in the optimization of the fermentation of Bacillus natto ZW-2 to produce ^-PGA, which was proved to be effective and economical.