Remziye Nalcacioglu
Karadeniz Technical University, Turkey
Title: Analysis of the vip3 genes in local Bacillus thuringiensis kurstaki strains and their insecticidal activity
Biography
Biography: Remziye Nalcacioglu
Abstract
A novel group of insecticidal proteins named vegetative insecticidal proteins (Vıp) are produced by Bacillus thuringiensis (Bt) bacteria during its vegetative stage. In this study we characterised the vip3 genes of two local Bt isolates (BnBt, MnD). Firstly, partial-purified Vip3 proteins of some local Bt isolates were tested against the Spodoptera littoralis larvae. After obtaining good insecticidal activity with BnBt and MnD isolates, Vip3 proteins of these bacteria were purified from supernatants of bacterial cultures by ion exchange chromatography. Purified proteins were subjected to SDS-PAGE analysis and 90 kDa band of proteins were determined. These purified proteins were tested against S. littoralis larvae. Results showed that Vip3 proteins of BnBt and MnD produced 86.66% and 83.33% insecticidal activity on S. littoralis larvae, respectively. The lethal concentrations (LC50) of BnBt and MnD were determined as 41.860 ng and 55.154 ng, respectively. These results suggest that vip3 genes of our local isolates may be alternatives for preventing resistance in various insect–pest species. Also these proteins may be used at developing bio-pesticides.