Study On The Breeding Of Strains And Fermentation Of Spinosad

A stable and high-yielding strain C121-11 was obtained from C121 strain of spinosyn producer Saccharopolyspora spinosa by stable experimentation. C121-11 strain was mutated by three methods protoplast-UV, N~+ transfusion, ~60Co-γ irradiation. The result showed that three mutation methods could enhance the fermentation ability of strains. The chemical titer of the three high-yielding mutant strains PU131 N229, Co329 were increased by 35.64%, 34.51%, 23.91% respectively compared with their parent strains. Subculture test indicated that PU131, N229, Co329 had relatively stable hereditary characteristics.In this dissertation, the medium composition was investigated with Co329. Based on primary medium, the effect of carbon, nitron, inorganic salts and microelement to fermentation were examined. We also screened the optional level of every component of the fermentation medium by orthogonal and equality experiments. The optimal medium composition was as follows(g/L): glucose 56g, soluble starch 32g, soybean oil 1g, cottonseed flour 20g, soybean meal 2g, corn steep liquor 10g, yeast extract 2g, CaCO3 5g, MgSO40.2g, NaCl 0.2g, ZnCl20.1g.In addition, the fermentation conditions for spionsad production was also investigated with Co329, the optimal fermentation conditions were as follows: the inoculum circle 2 days and the inoculum amount 10%, loading amount 50ml in 500ml shaking flask, shaking orbiting at 210r/min. The productivity of the optimal fermentation condition reached 900μg/ml, which was increased by 15.09% compared to that of the original fermentation condition.