活性污泥基因组DNA快速提取新方法及其指纹分析

建立了从活性污泥中快速提取基因组DNA的新方法，过程包括粗提与精制两个步骤，简化了繁琐的提取程序，提高了提取效率．用该方法提取的基因组DNA做模板，进行扩增核糖体限制性酶切片断分析（ARDRA）及核糖体基因间区序列分析（RISA），均获得了理想的多态性指纹图谱；采用两对特异性引物（鞘氨醇单胞菌属和氨加氧酶基因）对所提污泥基因组DNA进行扩增，均获得了正确的PCR产物．该方法提取的污泥基因组DNA不但适用于研究污泥系统中菌群多样性分析，而且还可以对特定基因进行跟踪监测。     

Comparison of Molecular Biological Techniques (RAPD, ARDRA and SSrRNA Gene Sequencing) on the Phylogenetic Relationships of Lower Taxa within Spirotrichous Ciliates

The evolutionary relationships of seven spirotrichous ciliates (3 stichotrichs: Oxytricha saltans, O. Ferruginea, Stylonychia mytilus; 4 hypotrichs: Uronychia transfuga, Diophrys appendiculata, Aspidisca steini, Euplotes vannus) inferred from the SSrRNA (small subunit rRNA) gene sequences and the polymorphic patterns of RAPD (random amplified polymorphic DNA) and ARDRA (amplified ribosomal DNA restriction analyses) fingerprinting are constructed. Compared with that of morphometric characters, the dendrograms from SSrRNA gene using three different calculation methods (distance matrix, maximum-parsimony, and UPGMA) agree with the morphological division into two clades, Oxytricha - Stylonychia and Uronychia - Diophrys - Aspidisca - Euplotes, though the branching orders within the hypotrichous ciliates are slightly different from morphometric analyses.     

青海柯柯盐湖16株细菌的ARDRA筛选及系统发育初步分析

 从青海柯柯盐湖泥样中分离的16株细菌,用2种限制性内切酶酶切进行ARDRA分析,其中12株菌的酶切带谱有较大差异.根据这12株菌的16SrDNA序列进行系统发育分析结果表明,12株菌有11株分布于芽孢杆菌科中的Halobacillus,Gracibacillus,Amphibacillus,Virgibacillus,Bacillus,Salibacillus和1个潜在的新属中,另1株属于Proteobacteria的Gamma亚群Halomonadaceae科,Halomonas属.而且16SrDNA系统发育分析提示这些菌株中存在3个新种和1个新属的可能.本研究得出的结论为:应用ARDRA来初步筛选菌株是可行的;青海柯柯盐湖这一极端环境中存在较丰富的新的芽孢菌种类.