重组大肠杆菌高效催化合成5-甲基吡嗪-2-羧酸

Efficient Catalytic Synthesis of 5-Methylpyrazine-2-carboxylic Acid by Recombinant Escherichia coli

摘要:

【目的】通过生物催化法提高5-甲基吡嗪-2-羧酸（5-methylpyrazine-2-carboxylic acid，MPCA）的产量和转化率。【方法】以大肠杆菌（Escherichia coli，E. coli）为模式生物构建MPCA合成体系，优化重组大肠杆菌的全细胞催化反应条件。通过紫外诱变技术对亲本宿主菌株进行诱变，筛选耐受高质量浓度2，5-二甲基吡嗪（dimethylpyrazine，DMP）的宿主菌株。【结果】重组诱变菌株在10 mL反应体系中可将10 g/L DMP在12 h内完全转化为MPCA，产量达12.9 g/L，摩尔转化率为100%；YB-CMAB全细胞催化剂循环利用3次耗时18 h，MPCA总产量达20.6 g/L，平均摩尔转化率为89%。【结论】该研究构建了一种高效、高转化率的全细胞催化合成MPCA的菌株，为MPCA的工业化生产提供了技术支撑。

Abstract:

[Objective] This study aimed to improve the yield and conversion rate of 5-methylpyrazine-2-carboxylic acid (MPCA) through biocatalysis.[Method] Escherichia coli (E.coli）was used as the model organism to construct an MPCA synthesis system, and the whole-cell catalytic reaction conditions of recombinant E. coli were optimized. In addition, the parental host strain was subjected to ultraviolet mutagenesis for the screening of host strains tolerant to high mass concentrations of 2,5-dimethylpyrazine (DMP).[Result] The recombinant mutagenized strain could completely convert 10 g/L DMP to MPCA within 12 h in a 10 mL reaction system, achieving a yield of 12.9 g/L and a corresponding molar conversion rate of 100%. The whole-cell catalyst YB-CMAB was recycled three times for 18 h, with a total MPCA yield of 20.6 g/L and an average molar conversion rate of 89%.[Conclusion] This study established an efficient whole-cell catalytic strain with a high conversion rate for MPCA synthesis, providing technical support for the industrial production of MPCA.