Isolation and characterization of Bacillus thuringiensis strains from olive-related habitats in Turkey

Abstract

Aims: To isolate Bacillus thuringiensis strains from different olive-related habitats (olive groves and olive oil factories) in Turkey and to characterize these strains by molecular methods. Methods and Results: A total of 150 samples, consisting of olive grove soil, green olive leaves, olive leaf residues, animal faeces, olive pomace and dust, were examined for the presence of B. thuringiensis. One hundred B. thuringiensis strains were isolated from 54 environmental samples (36%) and characterized in terms of crystal morphology, cry and cyt gene content by polymerase chain reaction, plasmid profiles and 16S-internal transcribed spacer ribosomal DNA restriction fragment length polymorphism (16S-ITS rDNA RFLP). The highest percentage of samples containing B. thuringiensis was found in 38 out of 54 total soil samples (70%). Of the 100 B. thuringiensis isolates, the most frequent crystal shapes were irregularly shaped (24%), spherical-irregular pointed (19%), cuboidal (17%) and spherical (16%). The cry1 plus cry4 genotype was the most abundant genotype in our collection (21%). RFLP analysis of the amplified 16S-ITS rDNA revealed 11 distinct patterns for the isolates and 10 reference strains. Conclusions: Bacillus thuringiensis isolates showed a great genetic diversity and crystal shape heterogeneity. Significance and Impact of the Study: This is the first study on the isolation and characterization of B. thuringiensis from olive-related habitats in Turkey. No correlation was observed between the cry genotypes and insecticidal crystal shapes of the isolates. Restriction profiles of 23% of the isolates were found to be different from those of the 10 reference strains used.State Planning Organization, DPT (2002K-120390

Distribution, occurrence of cry genes, and lepidopteran toxicity of native Bacillus thuringiensis isolated from fig tree environments in Aydın Province

“…Bt-based biopesticides are the main biopesticides used in agricultural pest control (Bravo et al, 2011). Worldwide isolation of Bt strains has been carried out to identify new cry genes and proteins with high toxic activity against the target insect species (Martin and Travers, 1989;Ben-Dov et al, 1997;Bravo et al, 1998;Uribe et al, 2003;Apaydin et al, 2005;Cinar et al, 2008;Seifinejad et al, 2008).…”

Detection of Multiple Cry Genes in Bacillus thuringiensis Isolated from Different Soil Types in Zaria

“…Researchers have also shown that microbial larvicides do not pose risk to wildlife, non-target species or the environment and retain a good activity in polluted water [10,11].…”

Presence and significance of Bacillus thuringiensis Cry proteins associated with the Andean weevil Premnotrypes vorax (Coleoptera: Curculionidae)

“…The cry 2 genes were the most frequently found in the native isolates collection (Table 1). A high frequency of cry 1 genes seems to be common to all B. thuringiensis strain collections analyzed so far (Bravo et al 1998, Hernández et al 2005, Cinar et al 2008. It is possible that cry 1 gene-containing strains may be more abundant.…”