Biological Assessment and Standardization Section, Environment and Climate Change Canada, 335 River Road, Ottawa, Ontario K1V 1C7, Canada.
Biological Assessment and Standardization Section, Environment and Climate Change Canada, 335 River Road, Ottawa, Ontario K1V 1C7, Canada.
Sci Total Environ. 2021 Apr 1;763:143037. doi: 10.1016/j.scitotenv.2020.143037. Epub 2020 Oct 16.
This study represents a holistic approach in assessing the effects of copper oxide nanoparticles (nCuO) on microbial health and community structure in soil amended with municipal biosolids. The biosolids were amended with nCuO (<50 nm) and mixed into a sandy loam soil at measured Cu concentrations of 27, 54, 123, 265 and 627 mg Cu kg soil. A suite of tests were used to assess the potential impact of nCuO on microbial growth, activity, and diversity. Microbial growth was determined by the heterotrophic plate count (HPC) method, while microbial diversity was assessed using both community level physiological profiling (CLPP) and 16S ribosomal DNA (rDNA) sequencing. Microbial activity was assessed by examining soil nitrification, organic matter decomposition, soil respiration (basal and substrate induced) and soil enzyme assays for dehydrogenase, phosphatase and β-glucosidase activities. As a readily soluble positive control, copper sulfate (CuSO) was used at measured Cu concentrations of 65, 140, 335 and 885 mg Cu kg soil for select tests, and at the highest concentration for the remaining tests. Analysis on Cu bioavailability revealed that extractable Cu was higher in CuSO-spiked soils than nCuO-spiked soils. At a nCuO exposure concentration of ≤265 mg Cu kg soil, stimulatory effects were observed in nitrification, β-glucosidase and community level physiological profiling (CLPP) tests. nCuO showed no significant inhibitory effects on the soil microbial growth, activity or diversity at the highest concentration (i.e. 627 mg Cu kg soil), with the exception of the dehydrogenase (i.e. ≥27 mg Cu kg soil) and phosphatase (i.e. 627 mg Cu kg soil) enzyme activities. In contrast, inhibition from CuSO at 885 mg Cu kg soil was observed in all tests with the exception of β-glucosidase enzyme activity. The growth of a Cu tolerant bacterium, Rhodanobacter sp., was observed at 885 mg Cu kg soil (CuSO).
本研究采用整体方法评估氧化铜纳米颗粒（nCuO）对添加城市生物固体的土壤中微生物健康和群落结构的影响。生物固体中添加了 nCuO（<50nm），并以测量的 Cu 浓度 27、54、123、265 和 627mg Cu kg 土壤混合到沙壤土中。使用一系列测试来评估 nCuO 对微生物生长、活性和多样性的潜在影响。微生物生长通过异养平板计数（HPC）方法确定，而微生物多样性则通过群落水平生理图谱（CLPP）和 16S 核糖体 DNA（rDNA）测序评估。微生物活性通过检查土壤硝化、有机质分解、土壤呼吸（基础和基质诱导）和土壤酶测定（脱氢酶、磷酸酶和β-葡萄糖苷酶活性）来评估。作为一种易溶的阳性对照，硫酸铜（CuSO）以测量的 Cu 浓度 65、140、335 和 885mg Cu kg 土壤用于选择测试，在其余测试中使用最高浓度。Cu 生物有效性分析表明，CuSO 污染土壤中的可提取 Cu 高于 nCuO 污染土壤。在 nCuO 暴露浓度≤265mg Cu kg 土壤时，硝化、β-葡萄糖苷酶和群落水平生理图谱（CLPP）测试中观察到刺激作用。在最高浓度（即 627mg Cu kg 土壤）下，nCuO 对土壤微生物生长、活性或多样性没有表现出显著的抑制作用，除了脱氢酶（即≥27mg Cu kg 土壤）和磷酸酶（即 627mg Cu kg 土壤）酶活性。相比之下，CuSO 在 885mg Cu kg 土壤中观察到所有测试的抑制作用，除了β-葡萄糖苷酶酶活性。在 885mg Cu kg 土壤（CuSO）中观察到一种耐 Cu 细菌 Rhodanobacter sp. 的生长。
