催化学报

催化学报 ›› 2011, Vol. 32 ›› Issue (8): 1405-1410.DOI: 10.3724/SP.J.1088.2011.10349

• 研究论文 • 上一篇    下一篇

水/有机溶剂双相体系中色氨酸合成酶酶法合成 L-色氨酸

徐礼生, 刘均忠, 王治元, 张宏娟, 刘伟, 刘茜, 焦庆才*   

  1. 南京大学生命科学学院, 医药生物技术国家重点实验室, 江苏南京 210093
  • 收稿日期:2011-04-18 修回日期:2011-05-09 出版日期:2011-08-05 发布日期:2014-12-26

Enzymatic Synthesis of L-Tryptophan Catalyzed by Tryptophan Synthase in a Water/Organic Solvent Biphase System

XU Lisheng, LIU Junzhong, WANG Zhiyuan, ZHANG Hongjuan, LIU Wei, LIU Qian, JIAO Qingcai*   

  1. State Key Laboratory of Pharmaceutical Biotechnology, School of Life Science, Nanjing University, Nanjing 210093, Jiangsu, China
  • Received:2011-04-18 Revised:2011-05-09 Online:2011-08-05 Published:2014-12-26

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929

被引次数

16

摘要： 在水/有机溶剂双相体系中, 利用重组大肠杆菌 DM206 [pET28a-trpBA/BL21(DE3)]色氨酸合成酶催化 L-丝氨酸和吲哚合成了 L-色氨酸. 考察了有机溶剂、有机相乙酸乙酯体积分数、反应温度、水相 pH、底物 L-丝氨酸与吲哚摩尔比、底物 L-丝氨酸浓度、表面活性剂和酶添加量对色氨酸合成酶酶活的影响. 结果表明, 酶法最佳转化条件为: 有机相溶剂为乙酸乙酯, 乙酸乙酯的体积分数为 2.5%, 反应温度为 35 ºC, 水相 pH 值为 8, 底物 L-丝氨酸与吲哚的摩尔比为 1:1.2, 底物 L-丝氨酸浓度为 100 mmol/L, 吐温 80 的质量分数为 0.4%, 反应介质中酶的添加量为 20 g/L. 在此条件下酶促反应 2.5 h, L-丝氨酸转化率可达 95%.

关键词: 色氨酸合成酶, L-色氨酸, L-丝氨酸, 吲哚, 乙酸乙酯, 水

Abstract: Enzymatic synthesis of L-tryptophan from L-serine and indole catalyzed by tryptophan synthase from recombinant Escherichia coli DM206 [pET28a-trpBA/BL21(DE3)] in an aqueous/organic biphasic system was carried out. The effects of organic solvents, volume fraction of ethyl acetate, reaction temperature, pH value of the aqueous phase, molar ratio of L-serine to indole, L-serine concentration, surfactants, and enzyme amount were investigated. Ethyl acetate was found to be the best organic solvent for the reaction. The optimal volume fraction of ethyl acetate was 2.5%. The optimal temperature and pH value were 35 ºC and 8, respectively. The optimal molar ratio of L-serine to indole was 1:1.2. The optimal L-serine concentration was 100 mmol/L. The optimal mass fraction of Tween 80 was 0.4%. The optimal enzyme amount was 20 g/L. Under the optimal conditions, bioconversion rate of L-serine reached 95% after 2.5 h in the aqueous/organic biphasic system.

Key words: tryptophan synthase, L-tryptophan, L-serine, indole, ethyl acetate, water