Fermentation Characteristics of Engineered Escherichia coli for Succinic Acid Producition

摘要

Succinic acid produced by microbial fermentation has good environmental benefits and attracted great interest currently.Among them,Escherichia coli have been chosen as good succinic acid producing strains because of their several advantages.Normally,no more than 0.2 mol of succinate is formed per mol of glucose consumed by E.coli.In order to improve the yield of succinic acid,a genetically modified E.coli JH204 was constructed using the RED recombination system and the flipase recognition target(FRT) site-specific recombinant technology,and multi-genes were knocked out from wild strain E.coli W,including ldhA,adhE,pflB,poxB and ackA to block the metabolic competition pathways.In this paper,the fermentation characteristics of the production of succinic acid by engineered strain was investigated.The mutant carries out a favourable fermentation of glucose in 10L fermenter,and the production of succinic acid was approximately 40.08g/L,and the productivity and yield was 0.83gL-1h-1 and 0.72g/g glucose,respectively.Acetic acid and lactic acid were the only other products detected and accumulated to concentrations of 4.53g/L and 0.08g/L,respectively.And formic acid and ethanol were not detected in the medium of the fermentation.