Recombinant Escherichia coli for synthesizing s-1,2-propanediol using L-lactic acid and its construction method

Abstract

The invention discloses a recombinant Escherichia coli which utilizes L-lactic acid to synthesize S-1,2-propanediol and a construction method thereof. The method comprises the following steps: 1) replacing the lldD gene, the adheE gene and the ackA-pta gene in Escherichia coli BW25113-△poxB with the encoding gene of 3-hydroxypropionate dehydrogenase and the coenzyme A-dependent succinate half The coding gene of aldehyde dehydrogenase and the coding gene of propionyl-CoA transferase, the obtained recombinant strain is marked as BWPDO1; 2) knock out the ldhA gene and dld gene of said BWPDO1, and obtain the recombinant strain BWPDO2; 3) introduce the The coding gene of pyruvate decarboxylase and the coding gene of NAD-dependent acetaldehyde coenzyme A dehydrogenase were introduced into BWPDO2 to obtain recombinant bacteria BWPDO3, which was the recombinant Escherichia coli. Experiments have proved that the recombinant Escherichia coli obtained in the present invention can use L-lactic acid to transform into S-1,2-propanediol, and use 200mM sodium lactate as a substrate to produce 3.4mM S-1,2-propanediol when cultured at 37°C for 24 hours. The invention lays the foundation for the work of improving the yield and conversion rate of 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 as 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 and can be used in food condiments and spices, or ointments and 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 has its own meta...

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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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