Micronized copper (Cu) azole (MCA) wood preservative formulations include Cu in nano form, and relatively little is known about longer term effects of Cu leached from MCA into wetland ecosystems. We tested the hypothesis that changes in soil microbiomes within reconstructed freshwater wetlands will be associated with exposure to elevated Cu concentrations originating from immersed MCA-treated wood stakes. Eight replicate communities were assembled with Willamette Valley (OR, USA) flood plain soil and clonally propagated wetland plants within mesocosms. Inundated communities were equilibrated for 5 months before installation of MCA or control southern yellow pine stakes (n = 4 communities/experimental group). Soil samples were collected for 16S and internal transcribed spacer amplicon sequencing to quantify responses in prokaryotes and eukaryotes, respectively, at 15 time points, spanning two simulated seasonal dry downs, for up to 678 days. Physiochemical properties of water and soil were monitored at 20 and 12 time points respectively, over the same period. For both taxonomic groups of organisms, phylogenetic diversity increased and was positively correlated with elapsed days. Furthermore, there was significant divergence among eukaryotes during the second year based on experimental group. Although the composition of taxa underwent succession over time, there was significantly reduced relative abundance of sequence variants from Gomphonema diatoms and Scutellinia fungi in communities where MCA wood stakes were present compared with the controls. These focused microbiome shifts were positively correlated with surface water Cu and soil Cu concentrations, which were significantly elevated in treated communities. The reconstructed communities were effective systems for assessing potential impacts to wetland microbiomes after exposure to released copper. The results further inform postcommercialization risk assessments on MCA-treated wood. Environ Toxicol Chem 2021;40:3351–3368. Published 2021. This article is a U.S. Government work and is in the public domain in the USA.

中文翻译：

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重建湿地中微生物组的集中变化与微粉化铜唑处理木材中铜浓度升高相关


微粉化铜 (Cu) 唑 (MCA) 木材防腐剂配方中含有纳米形式的铜，而对于从 MCA 浸出到湿地生态系统中的铜的长期影响知之甚少。我们测试了这样的假设：重建的淡水湿地内土壤微生物组的变化与暴露于浸没的 MCA 处理的木桩中铜浓度升高有关。八个复制群落由威拉米特谷（美国俄勒冈州）洪泛平原土壤和中生态系统内克隆繁殖的湿地植物组装而成。在安装 MCA 或对照南方黄松木桩之前，对被淹没的社区进行了 5 个月的平衡（ n = 4 个社区/实验组）。收集土壤样本进行 16S 和内部转录间隔扩增子测序，以分别量化原核生物和真核生物在 15 个时间点的反应，跨越两次模拟的季节性干旱，持续长达 678 天。同期分别监测20个和12个时间点的水和土壤的理化性质。对于这两个生物分类群，系统发育多样性都增加了，并且与经过的天数呈正相关。此外，基于实验组，第二年真核生物之间存在显着差异。尽管类群的组成随着时间的推移而发生演替，但与对照相比，存在 MCA 木桩的群落中Gomphonema硅藻和Scutellinia真菌的序列变异的相对丰度显着降低。这些重点微生物组的变化与地表水铜和土壤铜浓度呈正相关，这些浓度在经过处理的社区中显着升高。 重建的群落是评估暴露于释放的铜后对湿地微生物组潜在影响的有效系统。结果进一步为 MCA 处理木材的商业化后风险评估提供信息。环境毒理学2021；40：3351–3368。 2021 年出版。本文是美国政府的作品，在美国属于公共领域。