State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, Guangdong, China.
Department of Biological Sciences, Kent State University, Kent, OH, USA.
Microb Ecol. 2018 Oct;76(3):637-647. doi: 10.1007/s00248-018-1174-4. Epub 2018 Mar 16.
Bacterioplankton are the major driving force for biogeochemical cycles in estuarine ecosystems, but the communities that mediate these processes are largely unexplored. We sampled in the Pearl River Estuary (PRE) to examine potential differences in the taxonomic composition of resident (DNA-based) and active (RNA-based) bacterioplankton communities in free-living and particle-associated fractions. MiSeq sequencing data showed that the overall bacterial diversity in particle-associated fractions was higher than in free-living communities. Further in-depth analyses of the sequences revealed a positive correlation between resident and active bacterioplankton communities for the particle-associated fraction but not in the free-living fraction. However, a large overlapping of OTUs between free-living and particle-associated communities in PRE suggested that the two fractions may be actively exchanged. We also observed that the positive correlation between resident and active communities is more prominent among the abundant OTUs (relative abundance > 0.2%). Further, the results from the present study indicated that low-abundance bacterioplankton make an important contribution towards the metabolic activity in PRE.
浮游细菌是河口生态系统生物地球化学循环的主要驱动力，但介导这些过程的群落在很大程度上尚未被探索。我们在珠江口（PRE）进行了采样，以研究自由生活和颗粒相关部分中驻留（基于 DNA）和活跃（基于 RNA）浮游细菌群落的分类组成上的潜在差异。MiSeq 测序数据表明，颗粒相关部分中的整体细菌多样性高于自由生活群落。对序列的进一步深入分析表明，颗粒相关部分中驻留和活跃浮游细菌群落之间存在正相关，但在自由生活部分中不存在。然而，PRE 中自由生活和颗粒相关群落之间的 OTUs 大量重叠表明这两个部分可能在积极地交换。我们还观察到，在丰富的 OTUs（相对丰度 > 0.2%）中，驻留和活跃群落之间的正相关更为明显。此外，本研究的结果表明，低丰度浮游细菌对 PRE 中的代谢活性做出了重要贡献。
