Isolation, distribution and abundance of Bacillus thuringiensis Berliner from soils of India

Bacillus thuringiensis strains were isolated from soil samples using sodium acetate selection procedure. Besides, B. cereus, B. sphaericus, B. megaterium, B. mycoides and other unidentified members of Bacillus were also isolated. Out of 20 samples, 18 samples (90%) showed the presence of B.t. strains along with other bacteria. Out of 2655 bacterial colonies observed from all samples, 1679 were considered as B.t. colonies. Most of the B.t. isolates were obtained from forest soils, followed by high altitude mountainous soils and then plains. Soils from India were extraordinarily rich in B.t. The overall B.t. index for India soils was 0.63.