Biotoxicity assessment of cloned cry 11 protein gene from Bacillus thuringiensis 9NF.

The current investigation describes the isolation and characterization of toxic Bt. local isolates harboring 99% homology with Bti. prototoxin Bacillus thuringiensis (AXJ97553.1 and novel OUB27301.1) which contains full length cry11 gene (1.9 kb). Initially, it was cloned in pTZ57R/T and then sub-cloned in pET30a(+) for expression. The optimized conditions for good expression were found 1 mM IPTG, 3.5-4 h incubation time, and 37 °C. Toxicological assays were determined against 3rd instar larvae of Aedes aegypti with expressed partially purified and crude recombinant protein using recombinant E. coli BL21, DE3 transformed with cry11 gene. It was found that partially purified Bt. protein is highly toxic against A. aegypti larvae with LC50 value of 42.883 ± 6 µg/ml. B. thuringiensis strains producing Cry 11 toxic protein can be used as biopesticide to control resistance in insects.