耐氧双歧杆菌rDNA ISR序列测定及特征分析

Sequencing and characteristics analysis of 16S～23S rDNA ISR from oxyen-resistant Bifidobacterium

目的对4种耐氧双歧杆菌16S^23S rDNA ISR序列进行克隆和序列分析。方法采用凝胶分离PCR产物的方法。结果长双歧杆菌和短双歧杆菌16S^23S rDNA ISR序列一致,全长568个碱基对;青春双歧杆菌与婴儿双歧杆菌序列一致,全长510个碱基对。通过19种双歧杆菌和4种耐氧双歧杆菌ISR序列分析表明,该序列中含有一个保守的特征序列,可作为双歧杆菌属的分子标记,此外还含有3个基因高变区,可用双歧杆菌种间分子鉴定的基础。结论对23种双歧杆菌聚类分析表明,耐氧双歧杆菌ISR序列已发生改变,为进一步研究双歧杆菌在有氧条件下进化机制奠定了基础。

Objective Four types of rDNA 16S-23S intergenic spacer region（ISR）from oxygen-resistant Bifidobacterium were cloned and sequenced.Method Separated the PCR products form the agrose gel.Results The ISR sequence of Bifidobacterium longum containing 568 bp.was the same as Bifidobacerium breve and they were different from Bifidobacterum adolescentis and Bifidobacterium infantis which were only 510 bp.Through the ISR sequence analysis of 19 kinds Bifidobacterium and 4 kinds of oxygen-resistant Bifidobacterium,the results showed that there was a conservative and characteristic sequence of these genes,which could be used to the molecular marker of Bifidobacterium.Moreover,there were 3 high-variable regions,which could be provided a good basis for species identification work.Conclusion Chusters taxonomy analysis of 23 Bifidobacterium.indicatied that the ISR sequence of the oxygen-resistant had already changed.it had laid a foundation for the further research of the evolution mechanism of Bifidobacterium under the aerobic condition.