Isolation and characterization of some entomopathogenic Bacillus species

In this study, for the isolation and characterization of the entomopathogenic Bacillus bacterial species, samples were collected from the fruit garden soils and diseased fruit trees from five different localities in Amasya. From the samples, 29 sporulating Gram- positive bacteria were isolated on Nutrient Agar culture media. Morphological, physıological and biochemical charactheristics of them were identified (Gram+ , spores, hemolysis, indole, oxidase etc.). Later the Bacillus spp. were determined by using the standardized colorimetric identification system utilizing conventional biochemical tests. Later, 16s rDNA-based genetical identification of the Bacillus thuringiensis (Bt). Were performed for reasons including its universal distribution among bacteria and the presence of species-specific variable regions in five isolates (%97-99 probabilities). PCR and agarose gel electrophoresis were applied to the identified B. thuringiensis isolates for determination of the presence of the pesticidal cry gene in the newly identified Bt isolates. The PCR product profiles showed the presence of pesiticidal cry genes in two of the Bt isolates by comparision with our Standard Bt pesticide strain. After this molecular identification of the presence of cry genes as observed on the electrophoretic gel slabs, eventually, two new possible entomopathogenic Bt isolates (US19 and US20) to be used in a biological control, were obtained.