Culture Medium And Fermentation Process Optimization For Spinosad Production By Saccharopolyspora Spinosa

Spinosad is a set of secondary metabolites produced by soil microorganism Saccharopolyspora spinosa.Because of its broad spectrum of high insecticidal activity as well as friendliness to environment,Spinosad has become one of the most promising bio-pesticides.The low perfermence of Saccharopolyspora spinosa producing spinosad is an improtant bottleneck of its application.The production of spinosad is determined by its' genetic basis and closely related to culture conditions.Inorganic salts is important and indispensable for microbial growth and metabiolism.By single factor experiment,it's found that some common inorganic salts such as potassium hydrogen phosphate,calcium chloride,sodium chloride and so on have obvious role in promoting spinosad yield by Saccharopolyspora spinosa,with sodium chloride to promote the strongest,When fermentating in complex medium.Phosphate in improving spinosad production consists largely in the reason for the increase of mycelium concentration.By uniform design experiment,the components of culture medium for spinosad producing was optimized and the highest production,up to 465 mg/L,is 2.07 times that of initial conditions.Further study found that under conditions of high phosphate,a certain amount of calcium chloride or magnesium chloride being added to the medium in the fermentation process can further promote spinosad production,which may be related to the decreasing of soluble phosphorus content in the broth and then relieve the inhibition of dissolved phosphorus on spinosad synthsis.The materials of Oil class often added to antibiotics fermentation composite medium to promote fermentation yield.Butyl oleate can promote spinosad production when replace methyl oleate in complex medium.This study found that the metabolic by-products methanol from decomposition of methyl oleate may be toxic to mycelium growth and metabolism of the producer of spinosad while butyl oleate corresponding by-products n-butyl alcohol' poisoning effect is relatively small and have stimulation effect on spinosad syhthsis.It's also found that N-butyl alcohol have strong antagonism with sodium propionate as precursor substances of spinosad producing.Process of filling material is an important means of promoting secondary metabolites yield.The yield of spinosad increased by adding mixed materials of butyl oleate,corn steep liquor and magnesium chloride into the medium of spinosad fermentation process and then optimizing the supplementary policy under which conditions the highest yield of spinosad is 628.3mg/L.In shake flask culture conditions,this paper studied the composition of inorganic salt added,uniform design optimization,phosphate control,butyl oleate replace and the filling of mixed materials and other conditions on the effect of spinosad fermentation yield,provided a certain reference for spinosad produce which has a certain application value.