产生伴胞晶体的芽胞杆菌CTC菌株的16S-23SrRNA间隔区分析

Analysis of 16S -23S rRNA Space Region of Parasporal Crystal Forming Bacillus strain CTC

根据能形成伴胞晶体的特征,芽胞杆菌CTC菌株被鉴定为苏云金芽胞杆菌幕虫亚种。但该菌株明显不同于典型的苏云金芽胞杆菌,因为其伴胞晶体蛋白并不是由杀虫晶体蛋白基因编码,而是编码细胞表面S 层蛋白基因的产物,且伴胞晶体蛋白没有检测到对昆虫的毒性。本研究基于对CTC菌株及参照菌的16S-23SrRNA间隔区、编码S 层蛋白的基因进行扩增并测序,从系统发育水平检测到CTC菌株明显与苏云金芽胞杆菌幕虫亚种典型菌株T02存在差异,表明芽胞杆菌CTC菌株更接近蜡状芽胞杆菌。

Bacillus strain CTC had been identified to a serotype H2 of Bacillus thuringensis mainly owing to the fact that it has produced parasporal inclusion body. However, this strain is different from the Bacillus thuringiensis type strain because that its crystal is composed with cell surface S-layer protein but not typical insecticidal crystal protein and that it has no detectable toxicity to insects. This study amplified the nucleotide sequence of 16S-23S rRNA internal spacer region and S-layer protein gene from strain CTC and 6 strains of Bacillus cereus group. Sequence comparison showed that CTC strain is different from the type strain T02 and but very close to Bacillus cereus.