Redistribution of Intracellular Metabolic Flow in Improves Carbon Atom Economy for High-Yield 2,5-Dimethylpyrazine Production.

2,5-Dimethylpyrazine (2,5-DMP) is an important pharmaceutical intermediate and an important essence. Conventional chemical synthesis methods are often accompanied by toxic substances as by-products, and the biosynthesis efficiency of 2,5-DMP is insufficient for industrial applications. In this study, the and genes were overexpressed to enhance enzymatic and nonenzymatic reactions in metabolic pathways, and was knocked out to block competitive branching carbon flow metabolic pathways. Finally, a genetically engineered strain with the highest carbon recovery rate (30.18%) and the highest yield reported to date was successfully constructed, and 9.21 g·L threonine was able to produce 1682 mg·L 2,5-DMP after 24 h. At the same time, an expression regulation strategy and whole-cell biocatalysis helped to eliminate the damage to cells caused by 2,5-DMP, aminoacetone, and reactive oxygen species generated by aminoacetone oxidase from , and the negative effect of 2-amino-3-ketobutyrate CoA ligase on the yield of 2,5-DMP in was also demonstrated.