Liu Xie ^1,2 , Wenfei Zhang ^1,2 , Jiaxin Quan ^1,2 , Zhuoming Liu ^1,2 , Dawei Ye ³ , Youzhi Li ¹ , Xuanjun Fang ¹

1 College of Life Science and Technology, Guangxi University, Nanning, 530005; 2 Haide Institute of Tropical Agricultural Resources, Sanya, 572025; 3 College of Life Sciences, Nankai University, Tianjin, 300071
Author    Correspondence author
Molecular Soil Biology, 2010, Vol. 1, No. 1   
Received: 29 Oct., 2010    Accepted: 19 Nov., 2010    Published: 26 Nov., 2010

This article  was first published in Genomics and Applied Biology (Regular Print Version), and here was authorized to redistribute under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

A total of 264 soil samples were collected from Damingshan and Dawangling Natural Reserves in Guangxi Province of southern China. From those 264 soil samples, 597 Bacillus isolates were harvested; and among them, 16 isolates were further identified to be Bacillus thuringiesis using oil lens optical microscope and scanning electronic microscope. The isolation rate of these 264 soil samples is 6.06%. Among the 16 B. thuringiensis isolates, four isolates were observed to produce diamond parasporal crystal proteins and others produce different shapes of crystal proteins including circular and irregular shapes. The selected 16 isolates were analysed using PCR-RFLP and SDS-PAGE to identify their protein and genotype. The results showed that four B. thuringiensis isolates were identified as cry1Ac-genotype and encoding about 130 kD parasporal crystal protein; three isolates as cry40-genotype and one B. thuringiensis isolate as cry30-genotype, in which both encode about 75 kD parasporal crystal protein. The remaining eight isolates produce different sizes of proteins and genotype cannot be determines, thus further analysis is. Toxicity bioassay was carried out and results indicated that the four B. thuringiensis isolates with cry1 genotype exhibit high specific toxicity to Plutella xylostella larvae, but not the other 12 isolates.

Bacillus thuringiensis; Collection and identification; PCR-RFLP; SDS-PAGE