Escherichia coli for producing L-valine as well as construction method and application of escherichia coli

The invention discloses escherichia coli for producing L-valine as well as a construction method and application of the escherichia coli. According to the present invention, after the ycgH gene in the escherichia coli is knocked out and ilvC is expressed, or the combination of the knockout of the yjiT gene and the expression of brnF and brnE, the knockout of the yjiV gene and the expression of ilvE and ilvD, the knockout of the trpR gene and the expression of ilvH mutant protein, and the knockout of lacI and lacZ genes and the expression of DNA polymerase is performed, the obtained recombinant bacterium can improve the L-valine yield, can be used for producing the L-valine, and has good application prospects. 本发明公开了用于生产L-缬氨酸的大肠杆菌及其构建方法与应用。本发明发现将大肠杆菌中的ycgH基因敲除并表达ilvC后，或者结合敲除yjiT基因与表达brnF与brnE，敲除yjiV基因与表达ilvE与ilvD，敲除trpR基因与表达ilvH突变蛋白，敲除lacI与lacZ基因与表达DNA聚合酶，所得重组菌可提高L-缬氨酸产量，可用于生产L-缬氨酸，具有很好的应用前景。