The Develop Of The Two Kinds Of Insect Pathogenic Microorganisms Microcapsule

Microencapsulation is a process which coats the solid, liquid and gas substance. The natural and macromolecule material are chosen as capsule wall or envelope peplos which are used for coating active substance of core material. It will become the capsule membrane particles which has the property of semipermeability and tightness. The microencapsulation can avoid the core material losing activity because of the effect of external environment. The biological pesticide was easy to losing activity due to illumination, temperature, humidity and so on. Thus, its biological activity will prolong by preparing it into microcapsule formulation. The Bacillus thuringiensis, Beauveria bassiana, gelatin and Arabic gum were chosen as core material and shell material, respectively. The gelatin/gum Arabic-Bacillus thuringiensis microcapsule and gelatin/gum Arabic-Beauveria bassiana microcapsule were prepared by using complex coacervation method. The single factor experiment and orthogonal experiment was performed. Furthermore, the property of the microcapsule which includes morphological characteristics, particle size analysis, ultrastructure, the embedding rate, ultraviolet resistance measurement and indoor toxicity measurement were also measured.The optimum condition of the preparation of gelatin/gum Arabic-Bacillus thuringiensis microcapsule was obtained. The gelatin concentration was 1.0%, gum Arabic concentration was 1.0%, pH value of forming microcapsule was 3.6, stirring speed was 550r/min. The order of effect to microcapsule was the gelatin concentration＞pH value of forming microcapsule> gum Arabic concentration> stirring speed. The measurement of the property of microcapsule manifested that the appearance of microcapsule was regular. Bacillus thuringiens is successfully coated in microcapsules. The microencapsulation efficiency can reach 82.32%. The spherical solid microcapsules, which was liquidity, with even distribution of particle size and average diameter of about 28.29μm. 90% of the total content of microcapsules by 300 to sieve. The ultraviolet resistance measurement of gelatin/gum Arabic-Bacillus thuringiensis microcapsule was superior to Bacillus thuringiensis. Eventually, the indoor toxicity measurement demonstrated that the gelatin/gum Arabic-Bacillus thuringiensis microcapsule had the effect of controlled release. Not only did it improve the mortality ratio, but it also protected the core material prevent ultraviolet irradiation.The optimum condition of the preparation of gelatin/gum Arabic-Beauveria bassiana microcapsule was obtained. The gelatin concentration was 1.5%, gum Arabic concentration was 0.5%, the ratio of core material and shell material was 1:1.5, pH value of forming microcapsule was 3.8, stirring speed was 450r/min. The order of effect to microcapsule was the gelatin concentration> the ratio of core material and shell material> gum Arabic concentration >pH value of forming microcapsule> stirring speed. The measurement of the property of microcapsule manifested that the appearance of microcapsule was regular and the surface was smooth. The impurity is less. Beauveria bassiana successfully coated in microcapsules. The microencapsulation efficiency can reach 78.32%. The spherical solid microcapsules, which was liquidity, average diameter of about 44.16μm. And the most of the particles were distributed in the range of 39.14-70.35 μm.93.10% of the total content of microcapsules by 200 to sieve. The gelatin/gum Arabic-Beauveria bassiana microcapsule capsule skin effectively protect capsule core. Ultraviolet light 2 hours of live bacteria rate 66.16% higher than control. Under the same processing, capsule virulence of Malacosoma neustria testacea increased by 20%-40% than control.