Catalan Institute for Water Research (ICRA), Scientific and Technological Park of the University of Girona, Girona, Spain.
Group of Molecular Microbial Ecology, Institute of Aquatic Ecology, University of Girona, Girona, Spain.
Sci Rep. 2020 Jul 9;10(1):11288. doi: 10.1038/s41598-020-67774-0.
Spatial heterogeneity along river networks is interrupted by dams, affecting the transport, processing, and storage of organic matter, as well as the distribution of biota. We here investigated the structure of planktonic (free-living, FL), particle-attached (PA) and sediment-associated (SD) bacterial and archaeal communities within a small reservoir. We combined targeted-amplicon sequencing of bacterial and archaeal 16S rRNA genes in the DNA and RNA community fractions from FL, PA and SD, followed by imputed functional metagenomics, in order to unveil differences in their potential metabolic capabilities within the reservoir (tail, mid, and dam sections) and lifestyles (FL, PA, SD). Both bacterial and archaeal communities were structured according to their life-style preferences rather than to their location in the reservoir. Bacterial communities were richer and more diverse when attached to particles or inhabiting the sediment, while Archaea showed an opposing trend. Differences between PA and FL bacterial communities were consistent at functional level, the PA community showing higher potential capacity to degrade complex carbohydrates, aromatic compounds, and proteinaceous materials. Our results stressed that particle-attached prokaryotes were phylogenetically and metabolically distinct from their free-living counterparts, and that performed as hotspots for organic matter processing within the small reservoir.
河流网络中的空间异质性被大坝阻断，影响了有机物的运输、处理和储存，以及生物群的分布。我们在这里调查了一个小水库中浮游（自由生活，FL）、颗粒附着（PA）和沉积物相关（SD）细菌和古菌群落的结构。我们结合了 FL、PA 和 SD 中 DNA 和 RNA 群落部分的细菌和古菌 16S rRNA 基因的靶向扩增子测序，随后进行了推断的功能宏基因组学分析，以揭示水库中（尾部、中部和大坝段）和生活方式（FL、PA、SD）中它们潜在代谢能力的差异。细菌和古菌群落都根据其生活方式偏好而不是在水库中的位置进行结构划分。当附着在颗粒上或栖息在沉积物中时，细菌群落更丰富、更多样化，而古菌则呈现相反的趋势。PA 和 FL 细菌群落之间的差异在功能水平上是一致的，PA 群落具有更高的降解复杂碳水化合物、芳香族化合物和蛋白质类物质的潜在能力。我们的结果强调了颗粒附着的原核生物在系统发育和代谢上与其自由生活的对应物不同，并且是小水库中有机物处理的热点。
