Multilevel analysis of the bacterial diversity along the environmental gradient Rio de la Plata-South Atlantic Ocean
Multilevel analysis of the bacterial diversity along the environmental gradient Rio de la Plata-South Atlantic Ocean
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DOI：
10.3354/ame01439
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发表时间：
2010-01-01
影响因子：
1.4
通讯作者：
Amann, Rudolf
中科院分区：
文献类型：
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作者：
Alonso, Cecilia;Gomez-Pereira, Paola;Amann, Rudolf
拉普拉塔河是世界上最大的河口，是南美洲第二大盆地。尽管它在局部和全球范围内具有重要意义，但这是迄今为止首次尝试表征该系统的细菌多样性。我们采用了一套分子生物学方法来分析细菌的多样性在不同的系统发育水平，无论是在丰富度和均匀度，我们将这些发现的理化参数。一个明显的环境梯度观察到3个独特的区域（河流，锋，海洋）。反过来，细菌群落看起来高度多样化，并由环境强烈结构化。大量（324）不同的操作分类单位（OTU）的自动核糖体基因间间隔区分析（ARISA）进行了鉴定。ARISA结果表明，浮游细菌群落组成与水体理化性质密切相关，且与沉积物细菌组合重叠较少。催化报告沉积-荧光原位杂交（CARD-FISH）结果表明，Betaproteobacteria和Actinobacteria在河流区含量较高，而Gamaproteobacteria和Planctomycetes则偏好于海洋沃茨。拟杆菌的相对丰度在锋区达到峰值，和Alphaproteobacteria在整个河口的数量占主导地位。对大约300个几乎全长的16 S rRNA基因序列的分析表明，存在普遍存在的多型，但也表明某些群体的栖息地偏好。这第一次看的细菌群落的里约热内卢拉普拉塔表现出显着的多样性模式，提供了进一步的见解，全球分布的水生细菌群体的生态。
The Rio de la Plata is the world's largest estuary, draining the second largest basin of South America. In spite of its key significance at the local and global scale, this is the first attempt made so far to characterize the bacterial diversity of this system. We employed a suite of molecular methods to analyze the bacterial diversity at different phylogenetic levels, both in terms of richness and evenness, and we related these findings to physicochemical parameters. A clear environmental gradient was observed with 3 distinctive zones (riverine, frontal, and marine). In turn, the bacterial communities appeared highly diverse and strongly structured by the environment. A high number (324) of different operational taxonomic units (OTUs) were identified by automated ribosomal intergenic spacer analysis (ARISA). The ARISA results suggested that the composition of bacterioplankton communities was strongly related to physicochemical water characteristics, and that the bacterioplankton had little overlap with the bacterial assemblage of the sediments. Catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH) indicated that Betaproteobacteria and Actinobacteria were more abundant in the riverine zone, whereas Gammaproteobacteria and Planctomycetes preferred the marine waters. The relative abundance of Bacteroidetes peaked in the frontal zone, and Alphaproteobacteria were numerically dominant throughout the estuary. The analysis of about 300 almost full-length 16S rRNA gene sequences pointed to the existence of ubiquitous phylotypes, but also suggested habitat preferences among certain groups. This first look into the bacterial community of the Rio de la Plata demonstrated marked diversity patterns, providing further insights into the ecology of globally distributed groups of aquatic bacteria.