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Excellent mutant obtained through traditional breeding as the starting strain (treatment by NTG, EMS and UV), which resistance to feedback inhibition capability by all three branched-chain amino acids were improved, and L-lecuine yield up 18.5g L-1, glucose conversion rate was 17.5% (in 50L automatic fermenter under fed-batch fermentation conditions).However, it is difficult to further increase its production of L-leucine by conventional mutagenesis methods.Using metabolic engineering, an efficient L-leucine production strain of Corynebacterium glutamicum was developed.We obtained a feedback-resistant IPMS mutant ,which changes in three amino acid positions(R529H,G532D,L535V), then inserted into the shuttle expression vector pZ8-1, regulated under a strong promoter(tac promoter)in order to efficient expression of the rate-limiting enzyme, combined with additional metabolic modifications on the genome aimed at increasing L-leucine production.Under fed-batch conditions(50-L automatic fermenter), the best producer strain accumulated L-leucine to 38.1g L-1, the molar product yield was 0.42 mol L-leucine per mol glucose (glucose conversion rate attained 26.4%).Moreover, the same strain enlarged to 150 m3 fermenter, which can produce more than 37.5g L-1 L-leucine and the glucose conversion rate was 25.8%, making this process fully equipped with the ability of industrial production.