Recombinant Escherichia coli for synthesizing S-1,2-propanediol from L-lactic acid and construction method thereof

Abstract

The invention discloses a recombinant Escherichia coli for synthesizing S-1,2-propanediol from L-lactic acid and a construction method thereof. The method comprises the following steps: 1) respectively substituting lldD gene, adheE gene and ackA-pta gene in Escherichia coli BW25113-DELTApoxB with coding gene of 3-hydroxypropionate dehydrogenase, coding gene of coenzyme A-dependent succinic semialdehyde dehydrogenase and coding gene of propionyl coenzyme A transferase to obtain recombinant bacterium BWPDO1; 2) knocking out ldhA gene and dld gene of the BWPDO1 to obtain recombinant bacterium BWPDO2; and 3) transferring coding gene of pyruvate decarboxylase and coding gene of NAD-dependent acetaldehyde coenzyme A dehydrogenase into the BWPDO2 to obtain recombinant bacterium BWPDO3 which is the recombinant Escherichia coli. The experiment proves that the recombinant Escherichia coli can generate S-1,2-propanediol by converting L-lactic acid; and by using 200 mM of sodium lactate as the substrate, the culture is performed at 37 DEG C for 24 hours to generate 3.4 mM of S-1,2-propanediol. The recombinant Escherichia coli lays foundation for enhancing the yield and conversion rate of the biosynthetic S-1,2-propanediol.

Description

technical field [0001] The invention belongs to the field of microorganisms, and relates to a recombinant Escherichia coli for synthesizing S-1,2-propanediol by using L-lactic acid and a construction method thereof. Background technique [0002] The structural difference of propylene glycol distinguishes it into 1,2-propanediol and 1,3-propanediol. 1,2-propanediol is mainly used to produce unsaturated polyester resin, antifreeze, plasticizer to replace ethylene glycol for antifreeze aircraft and as coolant and heat carrier in food, etc. It can also be used in non-ionic detergent or moisturizer. Propylene glycol is also a good solvent, which can be used in food seasonings and fragrances, or ointments in the pharmaceutical industry. [0003] Optically active 1,2-propanediol has active groups and can be used as a chiral starting material for the synthesis of drugs, herbicides, pheromones and liquid crystals, and has high research value. Escherichia coli itself has a metaboli...

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Problems solved by technology

[0004] Regarding the research on the biocatalytic synthesis of R-1,2-propanediol, at present, foreign countries have reported on the biocatalytic synthesis of R-1,2-propanediol. , 2-propanediol and yeast oxidative resolution of racemic 1,2-propanediol have been studied, but they have not yet been applied industrially, and there are few reports in China

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