| According to the theory of metabolic control fermentation, the dissertation focuses on the breeding of L-lysine high-yielding strain and its fermentation condition. The main research contents and results are as follows:Brevibacerium flavum FY-222 as a starting strain was stepwise mutated with protoplast UV and Diethyl sulfate. One L-lysine high-producing strain BBCA-31(Thr-+SGr)with genetic marker was screened through shake tube primary screening, shake flask compound screening, genetic marker test and single clone isolation and continuous passage cultivation. This strain could produce L-lysine 96.4g/L after fermentation under the fermentation condition without being optimized. Genetic character of strain BBCA-31 was very stable.The protoplast formation rate and regeneration and fusion condition of strain BBCA-31and YYCA-21 was studied in this dissertation. One L-lysine high-producing strain ZL-231 was screened through protoplast fusion, shake flask compound screening, genetic marker test and single clone isolation and continuous passage cultivation. This strain could produce L-lysine 123.6g/L after fermentation under the fermentation condition without being optimized. Genetic character of strain ZL-231 was very stable.The batch fermentation conditions of strain ZL-231 in shake flask were studied in this dissertation. The proportions of seed medium were optimized by orthogonal design experiment and the seed culture condition was also studied. Based on the single factor experiment of fermentation medium, the shake fermentation medium was optimized by response surface analysis. The best fed-batch fermentation condition in shake flask was also determined after being studied. Under the optimiumcondition, L-lysien acid high-producing strain ZL-231 could produce L-lysine acid 147.3g/L and its inversion rate from glucose to L-lysine acid could reach 53.6% ,which increased 20.2% and 10.52% respectively related to the initial conddition(122.5g/L,48.5%).
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