| Verticillum lecanii is a well-documented entomopathogen, and was highly effective in control of homoptexan insects. It has been observed to cause epizootics in certain conditions. This fungus has been used as the active ingredient in commercial mycoinsecticides for biological control of aphids and whiteflies. Its products had been on sale in foreign countries, but in our country ,the related researches are in the primary stage , and it's crucial to development.This research aimed to find optimized culture conditions of liquid fermentation, and the main contents are as follows :1 .Basing on the criterions of fast germination and colony growth , and of rather high conidium production in solid and liquid culture medium ,CA-19 has been selected for the research of liquid fermentation from 8 types of V.lecanii.2.Through some parameters tested in the experiments of flask liquid culture, and tne ormonorrnal experiment of four factors three levels, optimized substrate and flask culture ocnditions were obtained (2% yeast , 2.5% glucose; 50ml subsrate capacity in 250ml flask, 1% inoculation).3. Obtained liquid fermentation techniqurs conditions are benefit to industrial fermentation production: DO(dissolution oxygen)^10-15% ; Original pH control in the range of 5.5 and 7.5 ; 5-10% inoculation ; Adopting different culture tempertures(from25C to 23C).4.Under that favoured conditions .some parameters are mensurated in 5L fermentationer liquid culture.After culturing about 3 Oh ,the concentration of spore top 2-3 X109 /ml , and we got fermentation kinetics equation : 25. 1-S = X2/3 (0.065t+0. 19).
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