Cloning and expression of key enzymes genes in biosynthesis of L-leucine

The gene encoding the key enzyme in the biosynthetic pathway of L-leucine from Brevibacterium flavum ATCC14067 genome was obtained by PCR. The gene inserted into E. coli-C glutamicum shuttle expression plasmid pDXW-8 to construct a variety of recombinant plasmid, which was transformed into type strain C. glutamicum ATCC13032 and investigated its fermentation production of L-leucine. The shake flask fermentation experiment showed that L-leucine was not accumulated in the fermentation broth of the control strain, while L-leucine accumulation of 4. 75g/L was detected in the fermentation broth of the genetically engineered strain ATCC13032/pDXW-8-leuA-ilvBNC.