The CONSTRUCTING EXPRESSION VECTOR CARRYING THE CRY1AC GENE DERIVED FROM BACILLUS THURINGIENSIS (BT) AND EXPRESSING IN PSEUDOMONAS FLUORESCENS

Abstract

Bacillus thuringiensis (Bt) is widely recognized as a biological insecticide employed globally due to its environmentally friendly alternative. The cry1Ac gene, which encodes a pesticidal crystal protein derived from Bacillus thuringiensis, was introduced into Pseudomonas fluorescens to enhance the stability of the toxin. In this study, the expression vector pUDBtAc was constructed to carry the gene encoding the Cry1Ac protein (65 kD) from Bt, under the control of the tac promoter and a kanamycin resistance gene as a selectable marker. The recombinant protein produced in the Pseudomonas fluorescens expression system under induction with 200–400 μM indole-3-acetic acid (IAA) was subsequently validated using anti-Cry1Ac antibodies. The results confirmed that the fusion cry1Ac gene was successfully designed and expressed in Pseudomonas fluorescens. Moreover, an analysis of insecticidal activity at a laboratory scale was also conducted. The findings demonstrated that the recombinant protein exhibited larvicidal effects against on caterpillar worm (Spodoptera litura) and this hold indicating promising potential for future applications in agricultural pest control.