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

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.