Isolation characterization and investigation of insecticidal properties of bacillus from warehouses

The genus of Bacillus is a spore-forming and Gram + bacteria that used mostly in biological control. In addition, they originate the basis of microbiological insecticide. In order to develop Bacillus strains with new toxin combinations, 26 bacterial isolate belonging to Bacillus sp. isolated from warehouses. Firstly, colonial and cellular characteristics, then, physiological features and finally, the biochemical properties of these isolates were analyzed by the light microscopy, manual tests and API kit, respectively. For the molecular characterization, 16S rDNA sequence and cry gene contents were detected. As a consequence of characterization, the isolates were identified as Bacillus thuringiensis, B. pumilus, B. subtilis, B. amyloliquefaciens, B. licheniformis, B. atrophaeus, B. megaterium and Lysinibacillus sphaericus. It was also recorded that the isolates Bg5 have a cry1 gene, B2, B3 and N6 have a cry3 genes. The toxic effects of the isolates were determined by the bioassay using larvae of Plodia interpunctella (Indianmeal moth), Ephestia kuehniella (Mediterranean flour moth) and adults of Sitophilus granarius (Wheat weevil). According to the results of bioassay, the highest insecticidal effects were 100% with Bg5 (Bacillus thuringiensis) against the larvae of P. interpunctella and 63.3% with B4 (B. subtilis) against the adult of S. granaries. Especially, Bg5 has the highest insecticidal effect may be valuable as a microbial control agent for lepidopteran warehouse pests.