Abstract: The diversity of bacterial groups in activated sludge samples received in different sewage treatment plants from different areas of China was investigated by combining with traditional pure culture technique and degeneration gradient gel electrophoresis (DGGE) approach. After the colonies were sequenced，the obtained sequence results by Blast analysis were used to construct the phylogenetic tree. Most bacteria were affiliated with the Betaproteobacteria，Gammaproteobacteria and Firmicutes. The DGGE patterns showed that there were many common bands in all systems，suggesting the high similarity of bacterial communities in different systems. Meanwhile，there were also specific bands in each sample. Also，the similarity in the same area is greater than that in different areas，which is mainly related to different natural and economic environment and people’s living habits.

Key words: activated sludge, bacterial groups, bacterial identification, DGGE, activated sludge, bacterial groups, bacterial identification, DGGE

摘要： 结合纯种分离纯化和变性梯度凝胶电泳法（DGGE）分析了中国不同区域污水处理厂的曝气池中活性污泥的微生物群落结构及差异性。其中，可培养微生物经纯化后对16s rDNA片段进行PCR扩增并测序，在Blast中分析后构建系统发育树。分离培养得到的89种细菌大部分属于β-变形菌门（Bataproteobacteria）、γ-变形菌门（Gamaproteobacteria）和厚壁菌门（Firmicutes）。DGGE分析表明所有活性污泥样品中的菌种丰富度都很高，不同的样品中存在很多相同的条带，是属于所有活性污泥中共有的优势菌群，说明不同的活性污泥系统具有高度的生物相似性；每个地区的样品中也都含有自己的特异条带。并且同一地区活性污泥的相似性大于不同地区活性污泥的相似性，主要与各地区不同的自然经济环境和人们的生活习惯相关。

关键词: 活性污泥, 微生物群落, 菌种鉴定, DGGE, 活性污泥, 微生物群落, 菌种鉴定, 变性梯度凝胶电泳