Expression of delta-endotoxin cryIA(c) gene of Bacillus thuringiensis in Escherichia coli and Streptomyces lividans.

The cryIA(c) gene of Bacillus thuringiensis was isolated from plasmid pOS1000. In order to obtain a proper cloning site and open reading frame, some DNA sequences preceding the initiating codon of the gene were replaced by synthetic oligonucleotide sequences. The isolated cryIA(c) was cloned into E. coli expression vector pKK223-3, and production of CryIA(c) protein was detected after induction by IPTG. A recombinant plasmid, pHZ1256, was constructed by insertion of the cryIA(c) gene into Streptomyces vector pHZ1272. pHZ1256 was introduced into Streptomyces lividans, and the production of CryIA(c) protein was confirmed by Western blotting after thiostrepton induction. A bioassy experiment showed that the CryIA(c) protein produced by E. coli and S. lividans caused 93% and 57% mortality to Plutella xylostella, respectively.