PCR-DGGE分析合肥市塘西河表层沉积物细菌群落结构空间分布特征  

Spatial characteristics analysis by PCR-DGGE for bacterial communities in surface sediments of Tangxi River, Hefei City

作　　者：沈烁[1] 杨长明[1] 成水平[1] 

机构地区：[1]同济大学教育部长江水环境重点实验室,上海200092

出　　处：《应用与环境生物学报》2015年第1期80-87,共8页Chinese Journal of Applied and Environmental Biology

基　　金：国家水体污染控制与治理科技重大专项(2011ZX07316-001)资助~~

摘　　要：微生物在城市内河沉积物物质循环和污染物释放过程中发挥着巨大的作用,其群落结构特征可作为评价城市河流入河污染负荷大小以及城市河流健康状况的重要依据.采用PCR-DGGE技术研究合肥滨湖新区塘西河不同河段表层沉积物细菌群落结构差异,对DGGE图谱中15条主要条带进行回收、扩增和测序对比,然后对采样点进行UPGMA聚类分析.同时,采用蒙特卡罗(Monte Carlo)检验和冗余分析(RDA)方法,探讨沉积物细菌群落结构与理化环境之间的关系.结果表明,塘西河不同采样点DGGE图谱具有一定的差异性,上游DGGE图谱条带数量多(平均大约为30条),但各条带的亮度差异不明显;中游条带数量少,平均仅为18条,但某些条带亮度大,表明该采样点沉积物中存在某些优势菌群;下游条带数量介于上游和中游之间,但也存在某些亮度较大的条带;上游采样点沉积物细菌Shannon多样性指数(H)平均为3.31,明显高于中游采样点,也略高于下游采样点.15个序列中,10个与Gen Bank中已登录的序列同源性高于98%,1个同源性为97%,4个相似的目前尚未获得纯培养;UPGMA聚类分析结果显示,塘西河表层沉积物中细菌群落结构分布存在明显的空间分异;Monte Carlo检验和RDA分析结果显示,离子交换态氮(IEF-N)对沉积物细菌群落的空间分布差异起到主导作用(特征值为0.188,P=0.134).结合塘西河水生植物分布特征分析,发现塘西河水生植被栽种对表层沉积物微生物群落丰度有一定的影响,且植被种类的影响作用较植被盖度更为明显.以上研究表明,表层沉积物细菌群落结构特征可以很好地表征塘西河流域城镇化程度以及生态恢复效果.Microbes play an important role in material circulation and pollutant release in urban sediments,and its community structure can provide an important basis for evaluating the pollution load and ecosystem health of an urban river.In this study,bacterial communities in sediments from different locations of Tangxi River in Anhui Province were analyzed and compared,with an objective of evaluating the effects of aquatic environment on spatial characteristics of bacterial communities and the feasibility of using bacterial community composition as an indicator of urban river health.PCR-DGGE was applied to analyze the bacterial communities;fifteen major bands of 16 S rDNA genes fragments from DGGE profiles of sediment samples were further eluted from gel,reamplified and sequenced.The sequences of these fragments were compared with the database in GenBank（NCBI）.The collected samples were clustered based on UPGM Aanalysis.In addition,relationships between bacterial communities and environmental factors were analyzed by Monte Carlo test and redundancy analysis（RDA）.The DGGE profiles indicated that upstream surface sediments had about 30 bands,but the differences in brightness were not significant.Although midstream surface sediments had only 18 bands on average,the brightness of some bands was relatively high,indicating that some dominant species of bacteria existed in these sediments.The amounts of bands in downstream sediments were between those of upstream and midstream,with some bands of high brightness.The NCBI comparison results showed that ten sequences shared 98-100%homology with known sequences,one with 97%,and the other four with uncultured bacteria.Shannon index（H） of bacterial diversity from upstream surface sediments was 3.31 on average,which was significantly（P〈0.05） higher than that of midstream surface sediments,and slightly higher than that of downstream surface sediments.UPGMA results showed both the distribution of bacteria communities and the diversity were strongly related with the sam

关 键 词：塘西河 表层沉积物 离子交换态氮(IEF-N) 微生物群落 PCR-DGGE 冗余分析(RDA) 

分 类 号：X172[环境科学与工程—环境科学]