Some of the genetic characterization of native Bacillus thuringiensis strains isolated from forest soil samples of Golestan province

Native strains of Bacillus thuringiensis (Bt) were isolated from forest soils of the different areas of Golestan Province and Cry and Vip genes, responsible of the effective toxin, were monitored. From a total of 42 soil samples examined through selective sodium acetate detention, 160 Bt isolates were separated. After planting the colonies, specific staining and microscopic identification were observed in 40% of isolates crystalline proteins that are toxic to many insects. Molecular study showed that in 12 isolates, gene Cry1 existed. Genetic structure tests for presence of 3 gene Cry1A (including Cry1Ac, Cry1Ab, Cry1Aa) and genes Cry1I, Cry1F, Cry2, Cry 9, Vip3Aa was carried out using the 8 pair of specific primers. Genes Cry1Ab, Cry2, Cry F were observed in all isolates, but the genes of Cry1Aa, Cry1I, Cry1Ac had very low frequency (Lower than 20%) or not found in any of the isolates. The results of this research could be very useful for tracking native Bt isolates that contain effective crystalline proteins for insects