Colibacillus engineering bacterium taking glucose as substrate for synthesizing muconic acid

Abstract

The invention discloses a colibacillus engineering bacterium taking glucose as a substrate for synthesizing muconic acid, and belongs to the field of biotechnology. 2,3-dihydroxy benzoic acid (2,3-DHB) is led to colibacillus during the metabolic pathway of muconic acid (MA); the metabolic pathway of colibacillus from glucose to 2,3-DHB is reinforced. The colibacillus engineering bacterium has the advantages that less foreign genes are required; the foreign gene expression load of a host bacterium is reduced; the incompatibility problem of the foreign genes is solved. Moreover, the host bacteria are not auxotroph; the foreign addition of expensive shikimic acid or other aromatic amino acid is avoided; the flask shaking fermentation yield of muconic acid is 1.15 g / L.

Description

technical field [0001] The invention relates to an Escherichia coli engineering bacterium which uses glucose as a substrate to synthesize muconic acid, and belongs to the field of biotechnology. Background technique [0002] Muconic acid, also known as hexadienedioic acid, has been extensively studied as a precursor and platform compound for the production of bioplastics. These products are mainly commercialized bulk chemicals such as adipic acid, terephthalic acid and trimellitic acid used in the manufacture of nylon 66, polyester synthetic fibers, dimethyl terephthalate, industrial plastics, pharmaceuticals, plasticizers Agents and cosmetics, etc. The consumption of adipic acid in the world has reached 3 million tons. The demand for adipic acid in my country is increasing every year, and the demand for polyurethane manufacturers is increasing by more than 10% every year. Traditional muconic acid chemical production methods mainly rely on non-renewable petroleum raw mater...

AI Technical Summary

Problems solved by technology

After 84 hours of fermentation in a 7.5L fermenter, the highest content of muconic acid reached 52g / L, which has application prospects, but a certain amount of shikimic acid was added to the medium to make up for the auxotrophic type of aromatic amino acids in Escherichia coli, and the price of shikimic acid Very expensive and increases the production cost of muconic acid

However, the synthesis of anthranilic acid from chorismic acid is a rate-limiting reaction, which requires the regeneration of glutamic acid; while the conversion of salicylic acid to catechol requires the participation of NADH, which increases the construction of muconic acid biosynthetic recombinant bacteria. Difficulty, limiting further increases in output

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