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。     

基因工程菌对偶氮染料脱色及生物强化作用

研究了基因工程菌Escherichia(E.)coli JM109(pGEX-AZR)对偶氮染料的脱色及生物强化能力.实验表明,合有10%E. coli JM109(pGEX-AZR)的强化体系对酸冲击的耐受能力没有提高,脱色率仅为80%;而对碱度及盐度的冲击表现出较强的耐受能力,脱色率超过90%.同时在AnSBRs中连续运行42 d,强化体系耐浓度冲击的能力和脱色率均高于对照体系.利用RISA测定微生物群落结构,E.coli JM109(pGEX-AZR)在强化体系中始终作为优势菌群存在并保持较高的代谢活性.     

Studies on the response of soil microflora to the application of the fungicide fenhexamid

The aim of this work was to evaluate the impact of the fungicide fenhexamid (FEX) on the genetic structure of soil bacterial communities using the Ribosomal Intergenic Spacer Analysis molecular technique. Using real-time PCR, we also tried to quantify the pcaH sequences which encode the dioxygenases involved in the degradation process of a variety of aromatic compounds. Soil taken from a vineyard in the Etna Park (Sicily, Italy) was treated with FEX in the ratio 2?µg?g^?1 soil every 7?days, the process being repeated four times. The analyses were carried out before treatment and 7?days after each further application of FEX. At the same time, the degradation rate was evaluated. The use of FEX determined a variation in the bacterial component of the soil which could be seen in an increase of some microbial strains and the inhibition of others. The pcaH sequence was already present in the genes of the soil microrganisms studied, but the use of FEX increased the number of the gene copies. These results suggest that the microbial population of the soil adapted to the presence of FEX with an increase in degradation potential. The measurements of the extent to which FEX was degraded confirm this hypothesis, showing that the molecule disappeared more quickly with successive applications.