中文摘要：

为研究黄河口潮滩细菌群落结构特征及其影响因素,本文于2012年5月在黄河口口门的潮间带区域,以变性梯度凝胶电泳（DGGE）为主要手段,分析了沉积物的生物学信息和主要理化参数（颗粒中值粒径、总氮、总磷、有机碳和叶绿素a）。结果显示,研究区域大致呈现出低有机碳、高营养盐的环境特征;DGGE图谱分析共获得38个不同位置的条带;多样性指数在表层沉积物中变化范围为2.38-2.64,垂直方向上从表到底逐渐降低（2.45-2.78）。NMDS分析显示,环境特征相近的细菌群落,其组成相似性较高。CCA分析中总氮、总磷、有机碳和叶绿素a对细菌群落组成影响显著。测序结果表明,该区域优势菌群隶属变形菌门（Proteobacteria）、酸杆菌门（Acidobacteria）,以及一些未分类的生物类群。

英文摘要：

In order to study the bacterial community composition and distribution in the intertidal mudflat of the Yellow River Estuary（YRE）,and issue the associated environmental factors,samples were collected in the high（H）,middle（M）and low（L）tide lines in May,2012,where was close to the mouth of Yellow River.Denaturing gradient gel electrophoresis（DGGE）was applied to obtain the bacterialinformation,sediments were also evaluated physical and chemical properties[i.e.,sediment median grain size（MD）,total nitrogen（TN）,total phosphorus（TP）,organic carbon（OC）and chlorophyll a（Chl a）].Results showed that,the investigated section presented a pattern of high nutrients and low organic carbon.A total of 38 bands were indentifiedfrom DGGE gel,the diversity index ranged at 2.38-2.64 in surface sediment,and decreased from surface to deep layers（2.45-2.78）.NMDSresults revealed thathigher similarity on bacterial community composition existed in more comparable environments,indicated by the closer position in clustering analysis.The first two CCA ordination axes suggested that bacterial community structure was strongly correlated with environmental variables[i.e.,TN,TP,OC and Chl a]（F=1.38,p0.05）.The dominated phylogenic groups in intertidal mudflat of YRE includedProteobacteria,Acidobacteria and some unidentified bacteria.