Overproduction of the Bacillus thuringiensis Vip3Aa16 toxin and study of its insecticidal activity against the carob moth Ectomyelois ceratoniae

Hanen Boukedi; Saoussen Ben Khedher; Nesrine Triki; Fakher Kamoun; Imen Saadaoui; Maissa Chakroun; Slim Tounsi; Lobna Abdelkefi-Mesrati

doi:10.1016/j.jip.2015.03.013

Overproduction of the Bacillus thuringiensis Vip3Aa16 toxin and study of its insecticidal activity against the carob moth Ectomyelois ceratoniae

J Invertebr Pathol. 2015 May:127:127-9. doi: 10.1016/j.jip.2015.03.013. Epub 2015 Apr 3.

Authors

Hanen Boukedi¹, Saoussen Ben Khedher¹, Nesrine Triki¹, Fakher Kamoun¹, Imen Saadaoui², Maissa Chakroun³, Slim Tounsi¹, Lobna Abdelkefi-Mesrati⁴

Affiliations

¹ Biopesticides Team (LPAP), Centre of Biotechnology of Sfax, P.O. Box "1177", 3018 Sfax, Tunisia.
² Algal Technologies Program, Centre for Sustainable Development, College of Arts and Sciences, Qatar University, Qatar.
³ Biopesticides Team (LPAP), Centre of Biotechnology of Sfax, P.O. Box "1177", 3018 Sfax, Tunisia; Departamento de Genética, Facultad de CC. Biológicas, Universidad de Valencia, Valencia, Spain.
⁴ Biopesticides Team (LPAP), Centre of Biotechnology of Sfax, P.O. Box "1177", 3018 Sfax, Tunisia. Electronic address: mesratilobna@yahoo.com.

PMID: 25843935
DOI: 10.1016/j.jip.2015.03.013

Abstract

The vip3Aa16 gene of Bacillus thuringiensis strain BUPM95 was cloned and expressed in Escherichia coli. Optimization of Vip3A16 protein expression was conducted using Plackett-Burman design and response surface methodology. Accordingly, the optimum Vip3A16 toxin production was 170μg/ml at 18h post-induction time and 39°C post-induction temperature. This corresponds to an improvement of 21times compared to the starting conditions. The insecticidal activity, evaluated against Ectomyelois ceratoniae, displayed an LC50 value of 40ng/cm(2) and the midgut histopathology of Vip3Aa16 fed larvae showed vacuolization of the cytoplasm, brush border membrane destruction, vesicle formation in the apical region and cellular disintegration.

Keywords: Bacillus thuringiensis; Ectomyelois ceratoniae; Escherichia coli; Toxicity; Vip3Aa16.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Bacillus thuringiensis
Bacterial Proteins / toxicity*
Insecticides / toxicity*
Moths / drug effects*

Substances

Bacterial Proteins
Insecticides
Vip3A protein, Bacillus thuringiensis