New Insecticide Microbial Resource Filter To Use

Microbial Pesticide is one of biological insecticidal resources. It's of some characteristics, it is easy to live, it can be cultured easily by fermentation, its use can't induce the destroy of entiroment balance, and the pests can't produce resistance. It showed that exploiting new pesticidal microbial resources is of important significance.Screening 37 strains which are of insecticidal activity from 2251 strains, the rate is 1.2%. The thesis mainly studied 100206 strain, 110104 strain and 110106 strain. The insecticidal activity, culture condition and activate substance of 110104 strain were studied. The results showed that the fermentated liquids of 110104 strain is of certain insecticidal activity againsting some familiar angricultral pests. And the soybean powder medium is the best fermentated medium that can produce toxins among several mediums which were tested in our experiments. By the initial isolation of toxic substance, it is found that the toxin is secreted to fermentation liquids, after treating the powders of 110104 fermentation liquids with six different organic solutions, it is found that ethyl acetate is the best valid extract solution of six organic solutions. Treating the fermentation liquids with this solution its insecticidal activity can beyond 50%.In the thesis, the insecticidal activity and culture characteristic of 110106 were studied. It was found that 110106 strain fermentation liquids expressed high insecticidal activity againsting several familiar agricultural pests. The molecular biology characteristics of 110106 strain was tested by PCR, the results showed that 110106 strain contain cryl gene and two fragaments were produced when it was digested by PstI and XbaI. one is about 1100bp,the other is about 500bp.The medium components and cultivation conditions of marine bacteria. 100206 were investigated by single-factor and orthogonal tests. And the result show that the best medium that can produce toxic substance was composed of starch 2.9%, soybean powder2.0%, glucose0.5%, yeast extract 0.2%, Calcium carbonate 0.2%, sea water 75.0% and water 25.0%. It's mortality reached 66.7%.