Characterization and toxicity of Bacillus thuringiensis serovar chanpaisis (H46): A serovar from Thailand

摘要

A new strain of Bacillus thuringiensis serovar chanpaisis was isolated from soil samples in Thailand. It was classifiedand characterized in terms of the crystal proteins, carbohydrates fermentation patterns, cry gene content, and its toxicologicalproperties against the species of Lepidoptera, Coleoptera, and Deptera. This strain was identified as Bacillus thuringiensisaccording to morphological and biochemical characteristics. The strain produced bipyramidal crystal proteins consisting of majorbands at about 130 kDa, 85kDa, 64kDa, 50kDa, and 20 kDa. A PCR analysis of the cry genes revealed that only cry32 genescould be detected and localized on chromosomal DNA and plasmid DNA of the organism. The bioassay showed that B.thuringiensis serovar chanpaisis had no larvicidal activity against any species of the Lepidoptera or Coleoptera but exhibitedmortality level against Aedes aegypti and Culex quinquefasciatus with LC50 values of 1.48×104 spores mL-1 and 1.00×104 sporesmL-1, respectively.