焦化废水处理系统中喹啉降解菌的种群特征

Community characteristics of quinoline-degrading bacteria in coking wastewater treatment system.

从首钢及武钢焦化废水处理系统中分离筛选出10株高效喹啉降解细菌,16 SrRNA鉴定表明它们分别属于假单胞菌及丛毛单胞菌2个属.对这些高效降解菌进行了降解基因片断的PCR扩增,发现所有假单胞菌属的喹啉降解菌均含有编码转化喹啉为2-羟基喹啉和2,8-二羟基喹啉的基因片断.16 SrRNA与降解基因系统发育树的对比分析,表明细菌进化过程中可能存在的基因突变和水平基因转移现象.根据假单胞菌属的喹啉降解菌降解基因的特异性,利用荧光原位杂交技术对该菌在首钢活性污泥中的种群空间分布进行了检测.另外,对高效降解菌的质粒分布做了初步的探讨,发现喹啉降解基因可能主要编码在细菌的染色体上.

Ten highly efficient quinoline-degrading bacteria strains were isolated and screened from the activated sludge in the coking wastewater treatment plants of the Capital Iron and Steel Group and the Wuhan Iron and Steel Group. 16S rRNA identification showed that the isolated bacteria belonged to two genera, Pseudomonas and Comamonas. Using polymerase chain reaction （PCR） amplification, the gene fragments encoding the transformation pathways from quinoline to 2-hydroxyquinoline,, and then to 2,8-dihydroxyquinoline, were detected from all quinoline-degrading bacteria of Pseudomonas. Phylogenetic comparison between 16S rRNA and degradation gene indicated that certain kinds of gene mutation and horizontal gene transfer might have happened in the evolution of the bacteria. According to the specific characteristics of degradation genes of Pseudomonas quinoline-degrading strains, fluorescent in situ hybridization （FISH） technology was used to monitor the spacial distribution of the strains in the sludge community. In addition, plasmid distribution in the quinoline-degrading bacteria strains was primarily investigated. The result demonstrated that the degradation genes were possibly encoded in the chromosomes for most degrading bacteria strains.