This Article Full Text (PDF) Other Versions of this Article: AEM.01346-08v1 74/22/6997    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Google Scholar Articles by Guo, S. Articles by Sun, M. PubMed PubMed Citation Articles by Guo, S. Articles by Sun, M. Agricola Articles by Guo, S. Articles by Sun, M.

 Previous Article  |  Next Article 

Appl. Environ. Microbiol. doi:10.1128/AEM.01346-08
Copyright (c) 2008, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

New strategy for isolating novel nematicidal crystal protein genes from Bacillus thuringiensis strain YBT-1518

State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, Hubei, People's Republic of China

^* To whom correspondence should be addressed. Email: m98sun{at}mail.hzau.edu.cn.

	Abstract

We have developed a strategy for isolating cry genes from Bacillus thuringiensis. The key steps are the construction of a DNA library in an acrystalliferous B. thuringiensis host strain and screening for the formation of crystal through optical microscopy observation and SDS-PAGE analyses. Using this method, three cry genes—cry55Aa1, cry6Aa2, and cry5Ba2—were cloned from rice-shaped crystals, producing B. thuringiensis YBT-1518 that consists of 54 and 45-kDa crystal proteins. Cry55Aa1 encoded a 45-kDa protein, cry6Aa2 encoded a 54-kDa protein, and cry5Ba2 remained cryptic in strain YBT-1518, as shown by SDS-PAGE or microscope observation. Proteins encoded by these three genes are all toxic to the root-knot nematode Meloidogyne hapla. The two genes cry55Aa1 and cry6Aa2 were found to be located on a plasmid with rather small size of 17.7 kb, designated pBMB0228.