Aguinaga Oscar E, McMahon Anna, White Keith N, Dean Andrew P, Pittman Jon K
School of Earth and Environmental Sciences, Faculty of Science and Engineering, University of Manchester, Manchester, United Kingdom.
School of Science and the Environment, Faculty of Science and Engineering, Manchester Metropolitan University, Manchester, United Kingdom.
Front Microbiol. 2018 Jun 27;9:1445. doi: 10.3389/fmicb.2018.01445. eCollection 2018.
Natural wetlands are known to play an important role in pollutant remediation, such as remediating acid mine drainage (AMD) from abandoned mine sites. However, many aspects of the microbiological mechanisms underlying AMD remediation within wetlands are poorly understood, including the role and composition of associated microbial communities. We have utilized an AMD-polluted river-wetland system to perform rRNA sequence analysis of microbial communities that play a role in biogeochemical activities that are linked to water quality improvement. Next-generation sequencing of bacterial 16S rRNA gene amplicons from river and wetland sediment samples identified variation in bacterial community structure and diversity on the basis of dissolved and particulate metal concentrations, sediment metal concentrations and other water chemistry parameters (pH and conductivity), and wetland plant presence. Metabolic reconstruction analysis allowed prediction of relative abundance of microbial metabolic pathways and revealed differences between samples that cluster on the basis of the severity of AMD pollution. Global metabolic activity was predicted to be significantly higher in unpolluted and wetland sediments in contrast to polluted river sediments, indicating a metabolic stress response to AMD pollution. This is one of the first studies to explore microbial community structure dynamics within a natural wetland exposed to AMD and our findings indicate that wetland ecosystems play critical roles in maintaining diversity and metabolic structure of sediment microbial communities subject to high levels of acidity and metal pollution. Moreover, these microbial communities are predicted to be important for the remediation action of the wetland.
众所周知，天然湿地在污染物修复中发挥着重要作用，比如对废弃矿场的酸性矿山排水（AMD）进行修复。然而，湿地内AMD修复背后的微生物学机制的许多方面仍知之甚少，包括相关微生物群落的作用和组成。我们利用一个受AMD污染的河流-湿地系统，对参与与水质改善相关的生物地球化学活动的微生物群落进行rRNA序列分析。对来自河流和湿地沉积物样本的细菌16S rRNA基因扩增子进行的新一代测序，根据溶解态和颗粒态金属浓度、沉积物金属浓度以及其他水化学参数（pH值和电导率）以及湿地植物的存在情况，确定了细菌群落结构和多样性的变化。代谢重建分析能够预测微生物代谢途径的相对丰度，并揭示了基于AMD污染严重程度聚类的样本之间的差异。预计未受污染的湿地沉积物中的总体代谢活性明显高于受污染的河流沉积物，这表明对AMD污染存在代谢应激反应。这是首批探索受AMD影响的天然湿地内微生物群落结构动态的研究之一，我们的研究结果表明，湿地生态系统在维持遭受高酸度和金属污染的沉积物微生物群落的多样性和代谢结构方面发挥着关键作用。此外，预计这些微生物群落对湿地的修复作用至关重要。
