Abstract. The Kilianstollen Marsberg (Rhenish Massif, Germany) has been extensively mined for copper ores, dating from Early Medieval Period till 1945. The exposed organic-rich alum shale rocks influenced by the diverse mine drainages at an ambient temperature of 10 °C could naturally enrich biogeochemically distinct heavy metal resistant microbiota. This metagenomic study evaluates the microbially colonized subterranean rocks of the abandoned copper mine Kilianstollen to characterize the colonization patterns and biogeochemical pathways of individual microbial groups. Under the selective pressure of the heavy metal contaminated environment at illuminated sites, Chloroflexi (Ktedonobacteria) and Cyanobacteria (Oxyphotobacteria) build up whitish-greenish biofilms. In contrast, Proteobacteria, Firmicutes and Actinobacteria dominate rocks around the uncontaminated spring water streams. The metagenomic analysis revealed that the heavy metal resistant microbiome was evidently involved in redox cycling of transition metals (Cu, Zn, Co, Ni, Mn, Fe, Cd, Hg). No deposition of metals or minerals, though, was observed by transmission electron microscopy in Ktedonobacteria biofilms which may be indicative for the presence of different detoxification pathways. The underlying heavy metal resistance mechanisms, as revealed by analysis of metagenome-assembled genomes, were mainly attributed to transition metal efflux pumps, redox enzymes, volatilization of Hg⁰, methylated intermediates of As(III) and reactive oxygen species detoxification pathways.

中文翻译：

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莱茵地块Marsberg铜矿微生物群落组成及生态位特征

摘要。Kilianstollen Marsberg（德国莱茵地块）从中世纪早期到 1945 年已广泛开采铜矿。在 10 °C 的环境温度下，受各种矿山排水影响的暴露的富含有机质的铝质页岩可以自然富集生物地球化学上独特的重金属抗性微生物群。这项宏基因组研究评估了废弃铜矿 Kilianstollen 的微生物定殖地下岩石，以表征单个微生物群的定殖模式和生物地球化学途径。下的重金属污染环境的照明在网站上的选择压力，绿弯菌门（Ktedonobacteria）和蓝藻（生氧光细菌) 建立白绿色生物膜。相比之下，变形菌、厚壁菌门和放线菌在未受污染的泉水溪流周围的岩石中占主导地位。宏基因组分析表明，抗重金属微生物组明显参与过渡金属（Cu、Zn、Co、Ni、Mn、Fe、Cd、Hg）的氧化还原循环。然而，通过透射电子显微镜在Ktedonobacteria生物膜中没有观察到金属或矿物质的沉积，这可能表明存在不同的解毒途径。宏基因组组装基因组分析揭示的潜在重金属抗性机制主要归因于过渡金属外排泵、氧化还原酶、汞的挥发⁰，As(III) 的甲基化中间体和活性氧物质解毒途径。