Links between Phytoplankton and Bacterial Community Dynamics in a Coastal Marine Environment
Links between Phytoplankton and Bacterial Community Dynamics in a Coastal Marine Environment
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DOI：
10.1007/s00248-003-1057-0
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发表时间：
2005-01
影响因子：
3.6
通讯作者：
J. Rooney-Varga;M. Giewat;Mary C. Savin;S. Sood;M. LeGresley;Jennifer L. Martin
中科院分区：
文献类型：
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作者：
J. Rooney-Varga;M. Giewat;Mary C. Savin;S. Sood;M. LeGresley;Jennifer L. Martin
在沿海海洋环境中，细菌和浮游植物的动态被认为是密切相关的，细菌和浮游植物生物量之间经常观察到相关性。相反，很少有人知道这些社区如何相互作用，在物种组成水平。本研究的目的是分析细菌群落动态在生产，沿海生态系统，并确定它们是否与浮游植物群落动态。2000年2月、5月、7月和9月，从芬迪湾的几个监测站采集了近地表海水样本。Savin等人（M.C. Savin等人，MicrobEcol 48：51 - 65）分析了同时收集的样品中的浮游植物群落。通过连续过滤将附着和自由生活的细菌群落分别收集到5 μ m和0.22 μ m孔径的过滤器上。从滤膜中提取DNA，扩增细菌16S rRNA基因片段，并通过变性梯度凝胶电泳（DGGE）进行分析。DGGE结果显示，自由生活的细菌群落的多样性和时间变异性低于附着的细菌群落。无论是附着和自由生活的社区占主导地位的theRoseobacterandCytophagroups的成员。对应分析（CA）排序图显示了类似的模式，浮游植物和附着的细菌群落，表明这些社区的物种组成的变化是有联系的。同样，典型的CA显示，浮游植物群落中硅藻的多样性，丰度和百分比占了显着的附着细菌群落组成的变化量。相比之下，排序分析并没有揭示自由生活的细菌和浮游植物之间的关联。这些结果表明，浮游植物和附着于它们的细菌之间存在特定的相互作用，并且这些相互作用影响两个群落的组成。
Bacteria and phytoplankton dynamics are thought to be closely linked in coastal marine environments, with correlations frequently observed between bacterial and phytoplankton biomass. In contrast, little is known about how these communities interact with each other at the species composition level. The purpose of the current study was to analyze bacterial community dynamics in a productive, coastal ecosystem and to determine whether they were related to phytoplankton community dynamics. Near-surface seawater samples were collected in February, May, July, and September 2000 from several stations in the Bay of Fundy. Savin et al. (M.C. Savin et al., Microb Ecol 48: 51-65) analyzed the phytoplankton community in simultaneously collected samples. The attached and free-living bacterial communities were collected by successive filtration onto 5 μm and 0.22 μm pore-size filters, respectively. DNA was extracted from filters and bacterial 16S rRNA gene fragments were amplified and analyzed by denaturing gradient gel electrophoresis (DGGE). DGGE revealed that diversity and temporal variability were lower in the free-living than the attached bacterial community. Both attached and free-living communities were dominated by members of theRoseobacterandCytophagagroups. Correspondence analysis (CA) ordination diagrams showed similar patterns for the phytoplankton and attached bacterial communities, indicating that shifts in the species composition of these communities were linked. Similarly, canonical CA revealed that the diversity, abundance, and percentage of diatoms in the phytoplankton community accounted for a significant amount of the variability in the attached bacterial community composition. In contrast, ordination analyses did not reveal an association between free-living bacteria and phytoplankton. These results suggest that there are specific interactions between phytoplankton and the bacteria attached to them, and that these interactions influence the composition of both communities.