Study On The Fermentation Conditions And Metabolic Regulation Of Spinosad

Spinosad is a novel macrolide insecticide from the aerobic fermentation of Saccharopolyspora spinosa.It has the advantages of safe,broad-spectrum,efficient and new insecticide mechanism.In this dissertation,the culture conditions of the slant seed,liquid seed,fermentation and continuous feeding fermentation and the continuous feeding fermentation of 5L fermentor were used to optimize the fermentation process were studied.The research about metabolic regulation was studied on sythesis of spinosad by changing respiratory or intensity of glycometabolism.The optimization of the slant medium,liquid seed medium and the culture conditions was carried out.The best slant medium was glucose 10g/L,yeast powder 1g/L,peptone 2g/L,beef extract 1g/L,agar 20g/L;the best liquid seed medium was glucose lOg/L,mannitol 60g/L,peptone 8g/L,cottonseed flour 35.2g/L,CaC03 3 g/L,KH2P04 1g/L,K2HP042g/L,pH7.5.The culture time of the slant medium were 5d.Orthogonal design was used to optimize fermentation medium for spinosad production.The results showed that the medium comprising glucose 60g/L,maltose 20g/L,corn steep 4g/L,bean oil 50g/L,proflo cottonseed flour 20g/L,Soybean meal 2.5g/L,peptone 25g/L,fumaric acid 0.5g/L,MnCl2·4H20 2*10-5g/L,KH2PO4 0.3g/L,CaC03 5g/L was the most suitable media for spinosad production,which can increase the productivity of spinosad from 89.49mg/L to 268.05mg/L.The curve of the growth of S.spinosa,utilization of glucose,utilization of amino nitrogen,pH and production of spinosad were studied by cultivated S.spinosa18 in the continuous feeding fermentation of a 5L fermentator.The production of spinosad was 327.78mg/L which is 23%more than that in the shaking flasks.Based on the biosynthetic pathway of spinosad,Neomycin,ferrocya-nide,fumaric acid,L-carnitine and glycerol were added to the extraction of fermentation,respectively.The produc-tion of spinosad was 18%,28%,53%,22%and 39%.