食品科学

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重组谷氨酸脱羧酶大肠杆菌合成γ-氨基丁酸条件的优化

陈 琳,张 充,吕凤霞,别小妹,赵海珍,陆兆新*   

  1. 南京农业大学食品科技学院,江苏 南京 210095
  • 出版日期:2015-01-15 发布日期:2015-01-16

Optimization of Conversion Conditions for Biosynthesizing γ-Aminobutyric Acid by Recombinant Glutamate Decarboxylase from Escherichia coli

CHEN Lin, ZHANG Chong, LÜ Fengxia, BIE Xiaomei, ZHAO Haizhen, LU Zhaoxin*   

  1. College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
  • Online:2015-01-15 Published:2015-01-16

摘要:

研究重组谷氨酸脱羧酶大肠杆菌合成γ-氨基丁酸(γ-aminobutyric acid,GABA)的适宜条件。检测温度、pH值、表面活性剂、金属离子、底物与菌体质量比以及反应体系体积对GABA转化效率的影响。结果表明:最优转化条件为:转化体系5 mL、底物L-谷氨酸钠浓度0.1 mol/L、重组大肠杆菌细胞6.4 mg(干质量)、Triton-100体积分数0.06%、Ca2+浓度0.6 mmol/L,转化温度45 ℃、反应体系pH 4.5。在该体系下反应7 h,GABA合成量达到26.1 g/L,GABA转化效率在1 h时达到最高,为13.8 g/(g•h),较优化前提高1.5 倍。

关键词: &gamma, -氨基丁酸, 谷氨酸脱羧酶, 转化条件, 优化

Abstract:

The conditions for the synthesis of γ-aminobutyric acid (GABA) using glutamate decarboxylase from recombinant
E. coli cells were optimized in this work. The effects of temperature, pH, surfactants, metal ions, the ratio of substrate and
cells and the transformation system volume on the productivity of GABA were studied. Results indicated that the optimal
reaction system volume was 5 mL containing 0.1 mol/L sodium glutamate as the substrate, 6.4 mg of E. coli cells (dry
weight), 0.06% Triton-100 (volume fraction) and 0.6 mmol/L Ca2+ at pH 4.5. The reaction was allowed to proceed for 7 h at
45 ℃. Under these optimal conditions, the yield of GABA was 26.1 g/L. The transformation efficiency of GABA reached
the highest level of 13.8 g/(g·h) after 1 h reaction, which is 2.5 times higher than that observed before optimization.

Key words: γ-aminobutyric acid (GABA), glutamate decarboxylase, conversion conditions, optimization

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