食品科学

• 生物工程 • 上一篇    下一篇

响应面法优化枯草芽孢杆菌产γ-聚谷氨酸发酵工艺

贺杨扬,曾 伟,王青龙,王大芸,陈桂光,梁智群   

  1. 广西大学生命科学与技术学院,亚热带农业生物资源保护与利用国家重点实验室,广西 南宁 530004
  • 出版日期:2014-05-15 发布日期:2014-05-19

Optimization of Medium Composition and Fermentation Conditions by Response Surface Methodology for the Production of Poly-γ-Glutamic Acid by Bacillus subtilis

HE Yang-yang, ZENG Wei, WANG Qing-long, WANG Da-yun, CHEN Gui-guang, LIANG Zhi-qun*   

  1. State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology,Guangxi University, Nanning 530004, China
  • Online:2014-05-15 Published:2014-05-19

摘要:

以1 株谷氨酸依赖型γ-聚谷氨酸(poly-γ-glutamic acid,γ-PGA)产生菌Bacillus subtilis GXA-28为研究对象,利用响应面法系统优化其γ-聚谷氨酸发酵培养基成分。通过单因素试验、Plackett-Burman试验、最陡爬坡试验以及Box-Behnken试验构建响应方程,利用该方程预测得到最优培养基:蔗糖33.65 g/L、酵母膏0.4 g/L、NH4Cl 1.6 g/L、谷氨酸钠15 g/L、 KH2PO4 0.4 g/L、K2HPO4·3H2O 1.68 g/L、MgSO4·7 H2O 0.1 g/L、MnSO4·H2O 0.04 g/L。利用优化培养基,在40.2 ℃、160 r/min条件下摇瓶发酵22 h,γ-PGA产量达到16.63 g/L,底物谷氨酸钠转化率比优化前提高了20%,达到100%。

关键词: &gamma, -聚谷氨酸, 枯草芽孢杆菌, 响应面分析, 发酵培养基

Abstract:

Poly-γ-glutamic acid, as a high molecular polymer produced by microorganism, is widely used in industry,
agriculture, food, medicine and cosmetics. This study aimed to use response surface methodology for a systematic
optimization of fermentation medium composition for the production of poly-γ-glutamic acid by a glutamic aciddependent
strain of Bacillus subtilis GXA-28. A response surface regression equation was established based on the
results of one-factor-at-a-time, Plackett-Burman, steepest ascent and Box-Behnken experimental designs. The optimal
medium formulation, as predicted from the equation, consisted of 33.65 g/L sucrose, 0.4 g/L yeast extract, 1.6 g/L
NH4Cl, 15 g/L monosodium glutamate, 0.4 g/L KH2PO4, 1.68 g/L K2HPO4·3H2O, 0.1 g/L MgSO4·7H2O and 0.04 g/L
MnSO4·H2O. The yield of poly-γ-glutamic acid reached 16.63 g/L, which was 20% higher than before the optimization,
and the conversion rate of the substrate glutamate reached 100% by using the optimized medium at 40.2 ℃ with shaking at
a speed of 160 r/min for 22 h.

Key words:  poly-γ-glutamic acid, Bacillus subtilis, response surface analysis, fermentation medium