Breeding Of L-leucine Producing Strain And Studies On Its Fermentation Condition

An L-leucine producing strain CFW32O of Brevibacterium /lavum was obtained by several times mutagenic treatments with diethyl sulfate (DES) and ultraviolet (UV), which required methionine for growth and could grow on the f3 -(2-thiazolyl)-DL-alanine (2-TA) and sulfaguanidine (SG) plates. Breeding mechanism of CFW32O strain was discussed in the paper. The measurement of L-leucine was studied in the paper. The measure standard curve of L-leucine was performed with paper chromatography. The relationship between the content of L-leucine in fermentation broth and the absorbency could be described by a expression. The optimum composition of seed culture medium and fermentation medium were obtained by orthogonal design method and response surface analysis (RSA) respectively. Fermentation condition was studied in the paper. Under the best culture condition, the strain CFW32O was able to accumulate L-leucine 14.6g/L.