Selection and characterization of Bacillus thuringiensis strains toxic against pyralid stored‐product pests. (8th January 2015)

• Record Type: Journal Article
• Authors: Azzouz, H.; Kebaili‐Ghribi, J.; Daoud, F.; Abdelmalak, N.; Ennouri, K.; Belguith‐Ben Hassan, N.; Tounsi, S.; Rouis, S.
• Is Part Of: Journal of applied entomology. Volume 139:Number 9(2015)
• Page Start: 690
• Page End: 700
• Publication Date: 2015-01-08
• Subjects: Entomology -- Periodicals; Insect pests -- Periodicals; 595.7
• DOI: 10.1111/jen.12205
• Languages: English
• ISSNs: 0931-2048

Abstract

<abstract abstract-type="main" id="jen12205-abs-0001"> <title>Abstract</title> <p>In this study, we present the selection and the characterization of <italic>Bacillus thuringiensis</italic> strains toxic against pyralid pests of stored products. Among 201 new <italic>B. thuringiensis</italic> strains isolated from different countries, two strains (BLB249 and BLB384) showed greater toxicity than the commercialized strain <italic>B. thuringiensis kurstaki </italic>HD1 against <italic>Ephestia kuehniella</italic> larvae. Morphological, molecular and biochemical investigations revealed that these strains were similar to HD1 but presented different <italic>cry</italic> gene content. Additional bioassays revealed that only strain BLB249 displayed higher toxicity than HD1 against <italic>Plodia interpunctella</italic> larvae. The study of Cry protoxin activation by midgut proteases of <italic>E. kuehniella</italic> and <italic>P. interpunctella</italic> larvae supported that higher toxicity of BLB249 and BLB384 strains compared to HD1 was not due to differential protoxin activation. Moreover, the toxic strains produced <italic>δ</italic>‐endotoxins and spores in similar amounts to HD1. Interestingly, the <italic>δ</italic>‐endotoxin production and the yield of BUPM26 strain were 32.87% and 35.12% greater than that of HD1. The potent insecticidal activities of BLB249 and BLB384 strains and the high level of <italic>δ</italic>‐endotoxin production by BUPM26 strain make them excellent candidates for use against <italic>E. kuehniella</italic> and <italic>P. interpunctella</italic> larvae.</p> </abstract>