Abstract
The present study aims to isolate the unknown and known serotypes of Bacilllus thuringiensis (Bt) from natural objects in Kyrgyzstan. A total of 83 Bt strains were isolated from natural substrates, of which 30% were taken from the soil and litter samples, 69.7% from dead insects and about 0.3% from slugs. Serological examination revealed that such subspecies as var. thuringiensis (H-1), var. alesti (H-3), var. sotto (H-4a4b) and var. entomocidus (H-6) predominated in the upper horizon of soils in all climatic zones. In the dead insects such species as subsp. thuringiensis, subsp. galleria, subsp. sotto, subsp. kurstaki, subsp. Aizawai and subsp. Entomocidus dominated. A set of Bt strains isolated from insects and soil samples, selected from different ecosystems in Kyrgyzstan was molecular taxonomically characterized using the pycA gene as marker for phylogenetic reconstruction. Within the Bacillus cereus sensu lato species complex, all Kyrgyz isolates were shown to belong to the B. cereus subspecies thuringiensis. Most isolates were assigned to the lineage Bt tolworthi, with two isolates each belonging to the lineages Bt kurstaki and Bt sotto. A high degree of cry gene diversity was demonstrated in the set of Bt isolates, with several gene copies simultaneously present in a single strain; a particularly conspicuous trait was the frequent combination of Lepidopteran-specific cryI with Dipteran-specific cryIV genes in the same Bt isolate.
Highlights
IntroductionBacillus thuringiensis is a gram-positive, spore-forming bacterium with a wide
A total of 83 Bacilllus thuringiensis (Bt) strains were isolated from these natural substrates, of which 30% were from the soil and litter samples, 69.7% were from the body of the dead insects, about 0.3% were from slugs
As results have shown B. thuringiensis seems to be indigenous to many environments, its strains have been isolated from many habitats, including soil, litter, insect bodies and slugs, collected from different ecosystems of Kyrgyzstan, where no Bt products have been applied before
Summary
Bacillus thuringiensis is a gram-positive, spore-forming bacterium with a wide. The optimal condition for the Cry toxin to grow and sporulate is in the insect’s alkaline gut. This facilitates the ability to infect insect guts. The primary action of Cry proteins is to lyse midgut epithelial cells through insertion into the target membrane and form pores [9]. Crystals are solubilized in the alkaline environment of midgut lumen and activated by host proteases [10]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
