Abstract: The disclosure discloses construction and application of an engineered strain of E. coli for producing malic acid by fixing CO2, and belongs to the field of fermentation. The engineered strain is obtained by performing genetic engineering transformation on Escherichia coli MG1655; the genetic engineering transformation includes knocking out a fumarate reductase gene, a fumarase gene, a lactate dehydrogenase gene and an alcohol dehydrogenase gene and freely overexpressing a formate dehydrogenase, an acetyl coenzyme A synthetase, an acylated acetaldehyde dehydrogenase, a formaldehyde lyase, a dihydroxyacetone kinase, a malic enzyme and a phosphite oxidoreductase to obtain a strain GH0407. The strain is used for producing malic acid by fermentation, anaerobic fermentation is performed for 72 hours with CO2 and glucose as a co-substrate, the production of malic acid reaches 39 g/L, the yield is 1.53 mol/mol, and accumulation of malic acid in the original strain is not achieved.

Abstract: The present invention relates to a recombinant strain for producing shikimic acid, in which a target gene that regulates the asymmetric cell division and target genes that regulate the shikimic acid production are expressed The target gene that regulates the asymmetric cell division includes cytoskeletal protein PopZ coding gene popZ, and the target genes that regulate the shikimic acid production include DAHP synthase coding gene aroG, 3-dehydroquinate synthase coding gene aroB, and transketolase coding gene tktA. The recombinant strain of the present invention realizes the de novo synthesis of shikimic acid using glucose as a substrate, with a low cost. After fermentation with the strain in a 7.5 L fermentor, the highest production of shikimic acid is 88.1 g/L, the yield is 0.33 g/g, and the production intensity of shikimic acid is 1.1 g/L/h.

Abstract: The disclosure discloses construction and application of an engineered strain of E. coli for producing malic acid by fixing CO2, and belongs to the field of fermentation. The engineered strain is obtained by performing genetic engineering transformation on Escherichia coli MG1655; the genetic engineering transformation includes knocking out a fumarate reductase gene, a fumarase gene, a lactate dehydrogenase gene and an alcohol dehydrogenase gene and freely overexpressing a formate dehydrogenase, an acetyl coenzyme A synthetase, an acylated acetaldehyde dehydrogenase, a formaldehyde lyase, a dihydroxyacetone kinase, a malic enzyme and a phosphite oxidoreductase to obtain a strain GH0407. The strain is used for producing malic acid by fermentation, anaerobic fermentation is performed for 72 hours with CO2 and glucose as a co-substrate, the production of malic acid reaches 39 g/L, the yield is 1.53 mol/mol, and accumulation of malic acid in the original strain is not achieved.