Isolation and Characterization of Strain of Bacillus thuringiensis subsp. Kenyae Containing Two Novel cry1-Type Toxin Genes

• Published in: Journal of microbiology and biotechnology Vol. 17; no. 9; pp. 1498 - 1503
• Main Authors: Choi, Jae-Young, Li, Ming Shun, Shim, Hee-Jin, Roh, Jong-Yul, Woo, Soo-Song, Jin, Byung-Rae, Boo, Kyung-Saeng, Je, Yeon-Ho
• Format: Journal Article
• Language: Korean
• Published: 한국미생물생명공학회 30.09.2007
• Subjects: Bacillus thuringiensis 2385-1; cry1-type gene; insecticidal activity; novel crystal protein; PCR-RFLP; PCR-RFLP; insecticidal activity; novel crystal protein; Bacillus thuringiensis 2385-1; cry1-type gene
• ISSN: 1017-7825; 1738-8872

To identify novel crystal proteins, Bacillus thuringiensis 2385-1 was isolated from Korean soil samples and characterized. The H-serotype of 2385-1 was identical to that of subsp. kenyae (H4a4c), and its crystal toxin was bipyramidal-shaped. However, 2385-1 showed a much higher toxicity towards Plutella xylostella and Spodoptera exigua larvae than subsp. kenyae. In addition, the crystal protein profile and plasmid DNA pattern of 2385-1 differed from those of subsp. kenyae. To verify the crystal protein gene types of 2385-1, a PCR-RFLP analysis was performed, and the results revealed that 2385-1 contained two novel cry1-type crystal protein genes, cryl-5 and cry1-12, in addition to the crylJal gene. The deduced amino acid sequences of cryl-5 and cry1-12 showed a 97.9% and 75.7% sequence similarity with the CrylAb and CrylJa crystal proteins, respectively. Among the novel crystal proteins, Cry1-5 showed a high toxicity towards P. xylostella and S. exigua larvae. In conclusion, B. thuringiensis 2385-1 is a new isolate in terms of its gene types, and should be a promising source for an insecticide to control lepidopteran larvae.