Anthropogenic metal contamination results in long-term environmental selective pressure with unclear impacts on bacterial communities, which comprise key players in ecosystem functioning. Since metal contamination poses serious toxicity and bioaccumulation issues, assessing their impact on environmental microbiomes is important to respond to current environmental and health issues. Despite elevated metal concentrations, the river sedimentary microbiome near the MetalEurop foundry (France) shows unexpected higher diversity compared with the upstream control site. In this work, a follow-up of the microbial community assembly during a metal contamination event was performed in microcosms with periodic renewal of the supernatant river water. Sediments of the control site were gradually exposed to a mixture of metals (Cd, Cu, Pb and Zn) in order to reach similar concentrations to MetalEurop sediments. Illumina sequencing of 16S rRNA gene amplicons was performed. Metal-resistant genes, czcA and pbrA, as well as IncP plasmid content, were assessed by quantitative PCR. The outcomes of this study support previous in situ observations showing that metals act as community assembly managers, increasing diversity. This work revealed progressive adaptation of the sediment microbiome through the selection of different metal-resistant mechanisms and cross-species interactions involving public good-providing bacteria co-occurring with the rest of the community.

中文翻译：

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金属诱导的细菌相互作用促进河流沉积物微生物群落的多样性。

人为金属污染导致长期的环境选择压力，对细菌群落的影响尚不清楚，而细菌群落是生态系统功能的关键参与者。由于金属污染会带来严重的毒性和生物累积问题，因此评估它们对环境微生物组的影响对于应对当前的环境和健康问题非常重要。尽管金属浓度升高，但与上游控制地点相比，MetalEurop 铸造厂（法国）附近的河流沉积微生物组显示出意想不到的更高多样性。在这项工作中，在微观世界中对金属污染事件期间的微生物群落组装进行了跟踪，并定期更新上清河水。控制点的沉积物逐渐暴露于金属混合物（Cd、Cu、Pb 和 Zn）以达到与 MetalEurop 沉积物相似的浓度。进行了 16S rRNA 基因扩增子的 Illumina 测序。通过定量 PCR 评估金属抗性基因 czcA 和 pbrA 以及 IncP 质粒含量。这项研究的结果支持先前的现场观察，表明金属充当社区集会管理者，增加了多样性。这项工作揭示了沉积物微生物组通过选择不同的金属抗性机制和涉及与社区其他部分共存的公共物品提供细菌的跨物种相互作用而逐渐适应。这项研究的结果支持先前的现场观察，表明金属充当社区集会管理者，增加了多样性。这项工作揭示了沉积物微生物组通过选择不同的金属抗性机制和涉及与社区其他部分共存的公共物品提供细菌的跨物种相互作用而逐渐适应。这项研究的结果支持先前的现场观察，表明金属充当社区集会管理者，增加了多样性。这项工作揭示了沉积物微生物组通过选择不同的金属抗性机制和涉及与社区其他部分共存的公共物品提供细菌的跨物种相互作用而逐渐适应。