title: Overproduction of the Bacillus thuringiensis Vip3Aa16 toxin and study of its insecticidal activity against the carob moth Ectomyelois ceratoniae.
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.
authors.affiliation: Biopesticides Team (LPAP), Centre of Biotechnology of Sfax, P.O. Box "1177", 3018 Sfax, Tunisia.
authors.forename: Hanen
authors.initials: H
authors.lastname: Boukedi
authors.affiliation: Biopesticides Team (LPAP), Centre of Biotechnology of Sfax, P.O. Box "1177", 3018 Sfax, Tunisia.
authors.forename: Saoussen
authors.initials: S
authors.lastname: Ben Khedher
authors.affiliation: Biopesticides Team (LPAP), Centre of Biotechnology of Sfax, P.O. Box "1177", 3018 Sfax, Tunisia.
authors.forename: Nesrine
authors.initials: N
authors.lastname: Triki
authors.affiliation: Biopesticides Team (LPAP), Centre of Biotechnology of Sfax, P.O. Box "1177", 3018 Sfax, Tunisia.
authors.forename: Fakher
authors.initials: F
authors.lastname: Kamoun
authors.affiliation: Algal Technologies Program, Centre for Sustainable Development, College of Arts and Sciences, Qatar University, Qatar.
authors.forename: Imen
authors.initials: I
authors.lastname: Saadaoui
authors.affiliation: 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.
authors.forename: Maissa
authors.initials: M
authors.lastname: Chakroun
authors.affiliation: Biopesticides Team (LPAP), Centre of Biotechnology of Sfax, P.O. Box "1177", 3018 Sfax, Tunisia.
authors.forename: Slim
authors.initials: S
authors.lastname: Tounsi
authors.affiliation: Biopesticides Team (LPAP), Centre of Biotechnology of Sfax, P.O. Box "1177", 3018 Sfax, Tunisia. Electronic address: mesratilobna@yahoo.com.
authors.forename: Lobna
authors.initials: L
authors.lastname: Abdelkefi-Mesrati
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis; D001426:Bacterial Proteins / Q000633:toxicity*; D007306:Insecticides / Q000633:toxicity*; D009036:Moths / Q000187:drug effects*
chemical_list: D001426:Bacterial Proteins; D007306:Insecticides; C447139:Vip3A protein, Bacillus thuringiensis
keywords: Bacillus thuringiensis; Ectomyelois ceratoniae; Escherichia coli; Toxicity; Vip3Aa16