The invention discloses a construction method and application of
escherichia coli
genetically engineered bacteria for producing
malic acid by synergistically utilizing CO2, and belongs to the technical field of bioengineering. According to the invention, an L-
malic acid chassis strain MG1655W (DE3) constructed by a
gene editing technology in a laboratory is used as an initial strain, a
lactic dehydrogenase encoding
gene ldhA and a
phosphate acetyltransferase encoding
gene pta in
escherichia coli are knocked out on the basis, the production paths of
lactic acid and
formic acid are blocked, and the yield of
lactic acid and
formic acid is increased. The method comprises the following steps of: firstly, amplifying a
phosphoenolpyruvate carboxylase gene ppc and a CO2
transporter gene CA, constructing a recombinant
plasmid, introducing the recombinant
plasmid pACYCDuet-1-CA-ppc into an expression host MG1655W (DE3)
delta ldhA
delta pta, and screening to obtain the
engineering bacterium MG1655W (DE3)
delta ldhA delta pta-CA-ppc by overexpressing the ppc gene and the CA gene and improving the CO2 immobilization and concentration capability of
escherichia coli. The obtained
engineering bacterium is subjected to
cell proliferation under an aerobic condition and
malic acid accumulation under an
oxygen limiting condition, the final malic acid yield is increased to 140-212%, and the
engineering bacterium has important industrial application value.