Vol. 3, Issue 7, Part B (2017)

Abstract
Rhizospheric soil was isolated from flowering stage of sesame plant. From the soil sample, a total of 22 strains of bacteria were isolated by the process of enrichment and isolation on nitrogen free medium. Out of these 22 strains, two were selected by their partial identification through 16S rRNA phylogeny. Growth characteristics were studied for two strains viz. tempetrature and pH requirement for growth. RM4 and RM5 showed 99% similarity with Sphingobium sp. The Bt-endotoxin was purified from Bacillus thuringiensis subsp. Kurstaki. Bioassay of isolated toxin was done on the larvae of Helicoverpa armigera to check their mortality and effectivity, and to calculate LC₅₀ of endotoxin. The integrity of protein was checked on 10% SDS-PAGE. The protein profiles of bacteria were compared in absence and in presence of two different condition of Cry1Ac endotoxin. Different protein profile was observed for the different concentration of toxin for the same strain.