Abstract:Pyruvate is an essential organic acid which plays an important role in the energy metabolism of living organisms. As a precursor, pyruvate can be involved in the biosynthesis of many organic compounds. Therefore, metabolic engineering was used to modify Corynebacterium glutamicum for pyruvate production. Five key genes (pyruvate quinone oxidoreductase gene pqo, pyruvate carboxykinase gene pyc, aminotransferase gene alaT, valine-pyruvate aminotransferase gene avtA, pyruvate dehydrogenase gene aceE), related to pyruvate metabolic tributaries in Corynebacterium glutamicum, were successfully knocked out by homologous recombination. The concentration of pyruvate reached 14.64g/L after 72h of fermentation in shaking flasks. Then, transketolase gene tkt, transaldolase gene tal, and phosphoenolpyruvate carboxykinase gene pck were overexpressed to increase the supply of precursors for pyruvate synthesis. After 72h of fermentation in shake flasks, pyruvate production reached 15.39g/L, which was 28 times higher than that of the wild-type strain. This study aimed to provide theoretical reference for application of pyruvic acid production by microbial fermentation.