A Comparative Study on Isolation and Identification of Bacillus thuringiensis from Different Localities of Gujranwala City
Keywords:Bacillus thuringiensis, Cry proteins, SDS-PAGE, biopesticide
This was a comparative study on isolation and identification of Bacillus thuringiensis isolates from different localities of city Gujranwala. Isolates of B. thuringiensis were identified using microscopic characters, colony morphology and biochemical characters. Then SDS-PAGE was performed to obtain a high protein profile on the basis of Cry proteins. A total of 74 out of 100 samples were found positive with B. thuringiensis. The maximum diversity of isolates was present in the soil (25%) as compared to other samples like dust (23.8%), cow dung (17.5%), donkey dung (17.5%) and bird droppings (16.2%). The average value of bacterial load was highest in soil (1 Â± 0.192 CFU/ml) and lowest in bird droppings (0.650 Â± 0.131 CFU/ml). The different sizes of bands with representative nine isolates from all sample sources on SDS-PAGE represent characteristics of crystal proteins having different target order specificity. It was concluded that B. thuringiensis is prevalent in various localities of the city. The need of the hour is to characterize these isolates and use them for pesticidal activity.