The Fermentation Process Conditions Of Biocontrol Myxobacteria Corallococcus Sp.EGB

Plant fungal disease is one of the main plant disease,causing hundreds of billions of dollars worldwide in economic losses,each year.At present,prevention and treatment of fungal disease is using of chemical pesticides and crop rotation,etc.,but using of pesticides can cause environmental pollution and ecological damage,which can't fundamentally solve the problem.With the concept of green agriculture,ecological agriculture,such as environmental protection,microbial pathogenic fungi gradually get the attention,and has good prospects for development?Myxobacteria is a predatory bacterium that exhibits complex social behavior.,gram-negative bacteria,have good antifungal capability.Corallococcus sp.EGB preserved in our laboratory,a lot of potential biocontrol microorganism that has found its broad-spectrum antifungal activity,which has good inhibition effect in cucumber fusarium,rice blast fungus,and cotton fusarium fungi.To cultivate Corallococcus sp.EGB is difficult with it special growing pathway.therefore research for the culture medium and culture conditions of the strain is necessary.This article first studied the Corallococcus sp.EGB the optimal culture medium and culture conditions in liquid.To determined the best carbon source,nitrogen source,metal ions,starch,yeast extract,magnesium sulfate respectively by single factor experiment,based on single factor experiments,Response surface methodology based on central composite design(CCD)experimental was design and establish a multiple quadratic regression equation to determine the optimal proportion for medium:starch 1.87%,yeast extract,0.61%,0.1%magnesium sulfate.Also determines the optimum temperature of 35? EGB liquid culture,the optimum pH 6.5 7.5,best inoculation quantity was 6%,the fshake flask for every 250 mL triangle in 100mL culture mediumIn solid cultivation experiment,first to study adding the starch,yeast,wheat bran,soybean meal for the impact on the growth of EGB,on the based of single factor experiments,response surface method of central composite design(CCD)of experiment to establish a multiple quadratic regression equation,to determine the composition of the various optimum adding amount,respectively,starch 2.25%,yeast 2.59%,bran 2.46%,3.5%soybean meal.The optimized medium of EGB biomass is 62%higher than basal medium.In addition to determine the optimal temperature of the solid state culture of 30 ?,the optimal initial pH 6.8 7.6,optimum water content is 75%,best inoculation amount is 15%.The study provides basic research data for the large-scale solid-state fermentation culture of Corallococcus sp.EGB.