Isolation,molecular characterization and toxicity of cry1C gene harboring bacillus thuringiensis from different habitats and localities of Pakistan

Bacillus thuringiensis (bt) is gram positive bacterium which forms endospores and produces parasporal crystals,which are toxic to specific lepidopterous and dipterous insects. in this study,70 spore former rods were selected from 470 bacterial colonies,obtained from 72 soil and sand samples from different habitats and parts of pakistan. out of these 70 strains,48 gave positive tests specific for bt. only three strains were positive for cry1c gene. three isolates (ms-sbs-bt1-3) were found positive for cry1ca,and two (ms-sbs-bt4-5) were found positive for cry1cb genes. all cry1c genes were 99% homologous when aligned on alignment tool blast. the optimum growth conditions and antibiotic sensitivity of the isolates were determined. bioassays showed that ms-sbsbt1 was more toxic to spodoptera litura,compared to control hd137,more toxic to musca domestica compared to control hd29,and less toxic to heliothes virescens compared to hd29. copyright 2013 zoological society of pakistan.