Characterization of Native Bacillus thuringiensis from the Western Ghats of Kerala

Eleven Bacillus thuringiensis isolates were obtained from the soils of Western Ghat region of Kerala. Morphology of the isolates on LBA media revealed similarity with Bacillus thuringiensis HDI. All the isolates produced creamy white, puffy colonies. Staining with Coomassie brilliant blue revealed the presence of dark blue crystal proteins having spherical, irregular, bipyramidal and triangular shapes. Biochemical characterization of the isolates showed variable response to hydrolysis of urea, starch and esculin. Profiling of cry1 and cry4 genes from B. thuringienis isolates was done using universal cry1 and cry4 primers for detection of cry genes and prediction of their insecticidal activities. Amplification with universal cry1 gene primer was obtained for eight isolates KY2, KY3, KY5, KY6, KK7 KY8, KY9 and EM11 along with the reference strain HD1. Presence of cry 4 gene, specific to dipteran larvae was detected in isolates KY1 and EM10.