Sensitivity to plating of Escherichia coli cells expressing the cryA gene from Bacillus thuringiensis var. israelensis

The gene (cytA) coding for the 27 kDa polypeptide of the Bacillus thuringiensis var. israelensis mosquito larvicidal δ-endotoxin, was cloned into a plasmid containing the T7 bacteriophage promoter. The plasmid was used to transform an Escherichia coli strain containing the T7 RNA polymerase gene 1, under the control of lacP. Loss of colony-forming ability without substantial lysis, associated with immediate inhibition of DNA synthesis, was observed after induction of transformed cells. The cytA gene product may kill E. colicells by disrupting their chromosome replicating apparatus.