Isolation and characterization of native bacillus thuringiensis from Artvin, Turkey, and screening against hypantaria cunea (lepidoptera)

Abstract

The soil in different regions may contain new B. thuringiensis species which may be toxic for the harmful insects. For this purpose, 5 native B. thuringiensis strains (Na1, Na2, Na5, Na7, Na25) were isolated from the soil of Artvin province in Turkey. The biochemical properties of the isolates (API 20 E and API 50 CH) were determined. The 16S rRNA gene sequence analyses, the polymerase chain reaction (ITS-PCR) of the 16S-23S intergenic transcribed spacer and the 16S rDNA based PCR-restriction fragment length polymorphism (RFLP) were performed. Then, cry gene content (cry 1, cry 2, cry 3, cry 4, and cry 9) of isolates were investigated. The conducted electron microscope research showed that the B. thuringiensis isolates carried four distinct crystal morphologies including rectangular, square, cubic, round and amorphous. The insecticidal effects of these isolates were investigated for 12 days in the 3-4th instar larvae of the Hypantria cunea (Lepidoptera). However, the isolates did not show any pathogenicity on the pest. In the later studies, it will be evaluated whether the isolates carry new crystal genes which are different from the control and whether they have entomopathogenic activity on different group of the insects.