Research and Innovation Centre, Fondazione Edmund Mach, via E. Mach 1, 38098 San Michele all'Adige, Italy; NBFC, National Biodiversity Future Center, Palermo 90133, Italy.
Research and Innovation Centre, Fondazione Edmund Mach, via E. Mach 1, 38098 San Michele all'Adige, Italy.
Sci Total Environ. 2024 Dec 1;954:176495. doi: 10.1016/j.scitotenv.2024.176495. Epub 2024 Sep 26.
Small water bodies, although supporting high biodiversity, are often understudied in the Alpine region. In this work, we characterized the planktic and benthic bacterial communities, as well as the water chemistry, of a wide physiographic range of 19 freshwater bodies within an Alpine Biosphere Reserve, including ponds, pasture ponds, peat bogs, shallow lakes, and lakes. We collected both water and surface sediment samples, followed by metabarcoding analysis based on the V3-V4 regions of the 16S rRNA gene. We investigated the changes in biodiversity and the distribution of unique and shared amplicon sequence variants (ASVs) between water (11,829 ASVs) and surface sediment (19,145 ASVs) habitats, as well as across different freshwater typologies. The majority of ASVs (78 %) were unique to a single sample, highlighting the variability and uniqueness of bacterial communities in such freshwater bodies. Most freshwater environments showed higher α-diversity in sediment samples (median, 1469 ASVs) compared to water (468 ASVs). We found that water and sediment habitats harboured unique bacterial communities with significant differences in their taxonomic compositions. Benthic bacteria were associated with several biogeochemical and degradative processes occurring in the sediments, with no notable differences among freshwater typologies and with phylogenetically and ecologically similar species. Conversely, planktic communities showed greater heterogeneity: small water bodies and peat bogs were characterized by higher relative abundances of Patescibacteria (up to 33 %), while lakes and shallow lakes were dominated by Actinobacteriota (up to 36 %). Cyanobacteria (426 ASVs) were generally distributed at low abundances in both water and sediment habitats. Overall, our results provided essential insights into the bacterial ecology of understudied environments such as ponds and pasture ponds and highlighted the importance of further exploring their rich pelagic and benthic bacterial biodiversity.
小型水体尽管具有高度的生物多样性，但在阿尔卑斯地区往往研究不足。在这项工作中，我们对一个阿尔卑斯生物圈保护区内广泛的地貌范围内的 19 个淡水体（包括池塘、牧场池塘、泥炭沼泽、浅湖和湖泊）的浮游和底栖细菌群落以及水化学进行了描述。我们采集了水样和底泥样本，随后进行了基于 16S rRNA 基因 V3-V4 区的 metabarcoding 分析。我们调查了水（11829 个 ASV）和底泥（19145 个 ASV）栖息地之间以及不同淡水类型之间生物多样性的变化和独特和共享扩增子序列变体 (ASV) 的分布。大多数 ASV（78%）仅存在于单个样本中，突出了这些淡水体中细菌群落的可变性和独特性。大多数淡水环境的沉积物样本具有更高的 α-多样性（中位数为 1469 个 ASV），而水样则较低（468 个 ASV）。我们发现水和沉积物栖息地拥有独特的细菌群落，其分类组成存在显著差异。底栖细菌与沉积物中发生的几种生物地球化学和降解过程有关，在不同的淡水类型之间没有明显差异，与系统发育和生态上相似的物种有关。相反，浮游群落表现出更大的异质性：小水体和泥炭沼泽的 Patescibacteria 相对丰度较高（高达 33%），而湖泊和浅湖则以 Actinobacteriota 为主（高达 36%）。蓝细菌（426 个 ASV）在水和沉积物栖息地中的分布通常较低。总的来说，我们的结果提供了对池塘和牧场池塘等研究不足的环境的细菌生态学的重要见解，并强调了进一步探索其丰富的浮游和底栖细菌生物多样性的重要性。
