黄河入海口水体细菌群落多样性及分布特征

The Diversity and Distribution Pattern of Bacterial Community in the Water of Yellow River Estuary

黄河入海口地处黄河、渤海湾与莱州湾交汇处,地理位置独特,微生物资源丰富,但关于该地区水体细菌群落的研究非常有限。以环境独特的黄河口为切入点,运用16S r DNA克隆文库法,旨在研究黄河口水体细菌群落多样性及分布特征。结果显示,从4个不同样点共得到11个门、18个纲、39个科、53个属的细菌。优势类群为变形菌门(α-、β-和γ-变形菌纲)、放线菌门、拟杆菌门和蓝细菌门。功能注释显示黄河口水体细菌主要参与碳、氮、硫等元素循环。基于物种组成或群落功能的聚类分析均可根据采样点聚为明显的两个分支——A、B和C、D。斯皮尔曼相关性分析(Spearman correlation analysis)及冗余分析(Redundancy analysis)表明环境因子(溶解氧、盐度及氮营养盐)对水体细菌群落结构及功能有显著影响。研究表明,黄河入海口水体细菌群落结构受黄河及环境因子影响呈现出不同的空间分布特征。本研究期望为初步掌握黄河河口及其邻近海域水体细菌多样性状况提供一定的参考,对进一步改善该区域河流和海洋环境提供数据支持,以及有助于该区域微生物资源的开发及水体生态系统的保护。

The Yellow River estuary,located in the confluence of Yellow River,Bohai Bay and Laizhou Bay,has unique geographyand abundant microbial resources. However,the researches on bacterial community in this area were very limited. Here we used 16 S r DNAclone libraries to explore the diversity and the characteristics of spatial distribution pattern of bacterial community in the unique estuarineecosystem. The results demonstrated that different 16 S r DNA clone libraries were constructed for 4 different water samples,and totally,wedetected the bacteria in Yellow River estuary in 11 phyla,18 classes,39 families and 53 genera. The dominant bacteria were attributed inProteobacteria（α-,β-,and γ-proteobacteria）,Actinobacteria,Bacteroidetes and Cyanobacteria. Functional annotation results showed thataquatic bacteria played key roles in the cycling of carbon,nitrogen and sulfur elements. Species-or function-based cluster analyses indicatedthat samples could be divided into two different branches,A,B and C,D,respectively. Spearman correlation analysis and redundancyanalysis（RDA） demonstrated that environmental factors（dissolved oxygen,salinity,and nitrogen nutrients） had significant effects on thestructures and functions of aquatic bacterial community. The study shows that both the Yellow River and environmental factors drive the structureof bacterial community into varied spatial distribution patterns along the estuary. This study is a preliminary glimpse of bacterial diversity in theYellow River estuary and adjacent seawater. It also provides data supports for further improvement in the rivers and marine environment of thisarea,and is beneficial to the microbial resource development and ecological protection of this water area.