Cloning and expression of Bacillus thuringiensis cry1B in Escherichia coli strain NiCo21

Bacillus thuringiensis produces crystal proteins, known as Cry proteins, that are toxic to certain target insects. The cry1B gene from B. thuringiensis was reported to be effective against the rice yellow stem borer [YSB, Scirpophaga incertulas]. The gene has been introduced into a Javanica rice cv Rojolele, by Agrobacterium mediated method, to improve its resistance against the Lepidopteran insect pest. To comply with the regulation for future release, food, and feed safety tests need to be performed, which involves characterization of the toxicity and allergenicity of the introduced Cry1B protein. In this experiment, the cry1B gene was cloned into pJ804:77539 expression vector to produce Cry1B protein under the pRHA promoter fused to a 6xHis tag to produce pJ804: cry1B. Expression of Cry1B protein was performed in Escherichia coli strain NiCo21 and was able to be detected by Western Blot using the anti-rabbit Cry1B polyclonal antibody and anti-His Detector. The results indicated that plasmid pJ804:cry1B expressed Cry1B in E. coli Nico21 and the system could be used to produce Cry1B protein for future studies.