几种分子生物学方法在菌种鉴定中的应用

REP-PCR指纹法、PCR-RFLP分析法、16S rDNA序列分析法在生物多样性研究、菌种鉴定、及微生物资源的开发应用中得到了广泛的应用，但最高分辩能力及适用性各不相同。该文采用上述方法对从厦门温泉分离刊的嗜热菌进行了鉴定分析，并对GeneBank数据库中的同源性较近的细菌16S rDNA序列进行比较，结果发现：在这三种鉴定方法中，REP-PCR法最简单，分辨能力最强，可鉴别16S rDNA序列同源性大于99.5％甚至完全相同的不同菌株；16S rDNA分析能快速准确地对微生物进行分类鉴定，它在分类学中的核心地位不可替代，但当16S rDNA序列同源性大干99.5％时难以获得准确的鉴定结果；PCR-RFLP法分辨力弱，可用于种到属水平的研究，16S rDNA序列相似性在96％以上，酶切图谱就难以区分了，但在不经过微生物分离培养的原位微生物多样性的研究中仍具有重要的作用。

Application of Several Molecular Biological Methods in Microbe Characterization

REP-PCR genomic fingerprinting,PCR-based RFLP analysis of genes encoding 16S rRNA,and 16S rDNA analysis,are widely used in microbiological research,such as biodiversity,Characteriza -tion,and exploiting micromiological resources,but these methods have different resolving power.Using these methods,we analysed the isolated strains of thermobacteria and relative 16S rDNA sequences in GeneBank.Results show that,among the three methods,REP-PCR is the simplist,most discriminating technique,it could discriminate isolates with a 99.5% to 100% rDNA similarity;16S rDNA analysis could characterize microbe quickly and accurately,it provides a phylogenetic framework which serves as the backbone for modern microbial taxonomy.But 16S rDNA analysis does not always show sufficient resolution to differentiate between species with a >99.5% degree of similarity;PCR-RFLP analysis has a weaker resolving power,amplified rDNA-RFLP analysis generates mostly species-specific patterns,while rDNA PCR-RFLP does not always show sufficient resolution to differentiate between 16S rDNA with more than 96% similarity,but it should be used to more efficiently and effectively describe microbial diversity prior to reaching the sequencing step.