Genetically engineered bacterium for sarcosine production as well as construction method and application

A genetically engineered bacterium for synthesizing Sarcosine, wherein the genetically engineered bacterium is Escherichia coli SAR which is obtained by using Escherichia coli ATCC27325 as a host and through the following transformations:

• integrating singly copied imine reductase gene dpkA, which is controlled by T7 promoter, at the mbhA site on its genome;
• singly copying citrate synthase gene gltA, which is controlled by trc promoter, at the ylbE site;
• knocking out glyoxylate cycle inhibitor gene iclR;
• knocking out malate synthase gene aceB;
• singly copying isocitrate lyase gene aceA, which is controlled by trc promoter, at the yeeP site;
• singly copying membrane-bound transhydrogenase gene pntAB, which is controlled by trc promoter, at the yghE site;
• knocking out 2-ketate reductase gene ycdW;
• singly copying phosphoenolpyruvate carboxylase gene ppc, which is controlled by controlled by trc promoter, at the yeeL site;
• and knocking out pyruvate kinase gene pykF;
• the imine reductase gene dpkA has a nucleotide sequence of SEQ ID NO:
• 1;
• the citrate synthase gene gltA has a nucleotide sequence of SEQ ID NO:
• 2;
• the isocitrate lyase gene aceA has a nucleotide sequence of SEQ ID NO:
• 3;
• the membrane-bound transhydrogenase gene pntAB has a nucleotide sequence of SEQ ID NO:4;
• the phosphoenolpyruvate carboxylase gene ppc has a nucleotide sequence of SEQ ID NO:5.