Isolation and Characterization of Gene Types in a Bacillus thuringiensis Strain Collection of China

摘要

The increasing of environmental contamination and the resistance of pests by chemical insecticides has caused the urgent need for novel alternative environmental-friendly insecticides. Bacillus thuringiensis is such the microorganism that has been the most successfully developed as a microbial insecticide in the world. According to the latest data, 171 Bt ICPs genes have been cloned, these genes have been divided into 28 groups of cry genes and 2 group of cyt genes (http://epunix. biols.susx.ac.uk/Home/Neil-Crickmore/Bt/index.html.). However, since a significant number of pests are not sensitive to the available Cry proteins, isolation for the wide spectrum and high activity natural Bt strains and the searching for novel ICPs genes has become a worldwide project. Several Bacillus thuringiensis strain collections have been described (A. Bravo, S. Sarabia, L. Lopez, H. Ontiveros, C. Abarca, A. Ortiz, M. Ortiz, L. Lina, F. J. Villalobos, G. Pena, M. N. Valdez, M. Soberon, and R. Quintero. Appli. Environ. Microbiol., 64, 4965 - 4972, 1998) including some Chinese researches on the Bt distribution in the forest soil and soil of southwest regions, etc. But there have no reports about the isolation and characterization of gene types in a Bacillus thuringiensis strain collection of various samples in different regions of China.