| Pochonia chlamydosporia is an important nematode biocontrol flingus,which belongs to the egg-destroying fungus.However,there are still few studies on the biocontrol agents,especially the reports of its preparations for animal parasitic diseases,which seriously hinders the application of the bio-control resource in practice.So,preparations of freeze-dried fungus and microcapsule,storage of microcapsule particles,the efficiency of the preparation on the prevention and control of animal parasite eggs was studied,following the study of the optimization of medium and mass production of fungal spores of P.chlamydosporia.The results were as follows:(1)The optimal growth medium for R chlaydosporia was PDA solid medium,and the optimum liquid fermentation medium was citric acid liquid medium,while wheat grain was the optimum solid fermentation medium.The time for spores production was 4 weeks for conidia and 5 weeks for chlamydospores,respectively.(2)Liquid-solid biphasic fermentation was performed to culture P.chlamydosporia and preparation of the microcapsules was carried out.The results indicated that skim milk powder was the most suitable lyoprotectant with 10%concentration as the best.Later,the preparation process was optimized by the embedding rate,the particle size and shape of the microcapsules.For the extrusion process,the CaCl2 concentration was 2.0%,and the sodium alginate concentration was 1.0%,while the needle type of the syringe is 14,and microcapsule particles were obtained with an average particle size of 2.43 mm and average embedding rate of 77.5%;For the emulsification method,the optimized stirring speed is 400 r/min;The optimum storage temperature for microcapsules was 4℃.(3)P.chlamydosporia had obvious effects on uninfective eggs and infective eggs of Ascaris suum.On the 28th day,the infection rate of P.chlamydosporia on uninfective eggs of A.suum was 94.67%,while it was 91.33%for the infection rate of infected eggs.In addition,P.chlamydosporia also had a good infective effect on coccidia oocysts.The microcapsules of P.chlamydosporia could pass the digestive tract and survive.Through the research,the optimal medium of P.chlamydosporia was determined,and the microcapsule granules of P.chlamydosporia were prepared,which would provide the foundation for the clinical application of the fungus in the future,and had important application value for animal husbandry,so it had great significance for the prevention and control of veterinary parasites. |
