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AssigneeTianjin University of Science and Technology
InventorsZhengxiang Wang, Dandan Niu, Meng Wang
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Provided is a method for synthesizing lactic acid monomers using sucrose as raw material. Through site-directed gene replacement genetic recombination technology, the method modifies the promoter sequence of the sucrose metabolism operon in the production strain, enabling it to maintain high-level expression throughout the entire production process of lactic acid monomers. The strain exhibits significant ability to efficiently catabolize sucrose for synthesizing lactic acid monomers (D-lactic acid or L-lactic acid) with high optical purity and high chemical purity. Fermentation levels of D-lactic acid and L-lactic acid for strains DSAPW5 and LSAPW5 at 25~50° C. for 28~30 hours can reach 158.58 g/L and 159.65 g/L, respectively, with optical purities of 99.94% and 99.95%. The present disclosure can be applied to the industrial production of lactic acid monomers using sucrose or sucrose-containing raw materials.
A method for improving the ability of Escherichia coli to synthesize lactic acid monomers using sucrose, wherein, the method is replacing a promoter of the sucrose metabolism operon cscAKB in the genome of the lactic acid monomer-producing strain with an anaerobic promoter;
An Escherichia coli recombinant strain capable of synthesizing lactic acid monomers using sucrose, wherein, the recombinant strain is obtained by taking an Escherichia coli strain capable of synthesizing lactic acid monomers from the sugar metabolism intermediate pyruvate as the starting strain, and replacing the promoter of the sucrose metabolism operon cscAKB in the genome with an anaerobic promoter;
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