In order to understand the purification processes of bacteria communities in reclaimed water replenishment constructed wetlands, this study employed 16S rDNA clone library technique to analyze the community diversity of endophytic bacteria in roots of typha, which growed in Baihe constructed wetland in Miyun. We further investigated the relationship between endophytic bacteria communities and water quality factors. The results of 16S rDNA clone library showed that community included four major groups: the most dominant phylum was Proteobacteria (92.85%), including Gammaproteobacteria (63.04%), Betaproteobacteria (26.09%), Epsilonproteobacteria (2.48%) and Alphaproteobacteria (1.24%); The second group was Firmicutes (1.24%); the third phylum was Verrucomicrobia (0.62%); the fourth phylum was Bacteroidetes (0.31%). Additionally, 4.65% bacteria was unclassified. Stepwise discriminant analysis suggested that endophytic bacteria in roots of typha were significantly important in the geochemical cycle in reclaimed water replenishment wetlands. Specificially, 41.60% clones involved in the nitrogen cycle in wetlands, 12.42% clones involved in the phosphorus cycle in wetland, 14.92% of clones involved in the carbon cycle in wetland, 26.08% of clones involved in the metabolism of organic matter, 11.8% of the clones absorption of heavy metal matter. Thus, endophytic bacteria in plants may play a major role in the process of removal of nitrogen, nitrification and denitrification except for phosphorus removal. As our results concluded through single sampling, more evidences should be abtained by multi temporal sampling.%以北京白河人工湿地再生水补水河段香蒲根为研究对象,采用16S rDNA克隆文库技术对香蒲根内生细菌群落多样性进行分析,得出该克隆文库包括4大类群细菌,最优势类群为变形杆菌门 Proteobacteria,其中包括 Gammaproteobacteria、Betaproteobacteria、Epsilonproteobacteria、Alphaproteobacteria；其次为厚壁菌门Firmicutes、疣微菌门Verrucomicrobia、拟杆菌门Bacteroidetes；另外还包括部分非培养未确定种属的细菌.结合研究区再生水排放口与湿地下游水质数据,得出TN、TP、NO3-去除率达到了42.15%、47.34%、28.56%,表明湿地对再生水中的TN、TP、NO3-具有明显去除机制,说明香蒲根内生细菌克隆文库中菌株与湿地氮、磷等生物地球循环关系密切.
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