School of Biology and Environmental Science and Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland.
Ecotoxicology. 2017 Apr;26(3):449-458. doi: 10.1007/s10646-017-1776-5. Epub 2017 Feb 14.
Soil microorganisms are key contributors to nutrient cycling and are essential for the maintenance of healthy soils and sustainable agriculture. Although the antimicrobial effects of a broad range of nanoparticulate substances have been characterised in vitro, little is known about the impact of these compounds on microbial communities in environments such as soil. In this study, the effect of three widely used nanoparticulates (silver, silicon dioxide and aluminium oxide) on bacterial and fungal communities in an agricultural pastureland soil was examined in a microcosm-based experiment using a combination of enzyme analysis, molecular fingerprinting and amplicon sequencing. A relatively low concentration of silver nanoparticles (AgNPs) significantly reduced total soil dehydrogenase and urease activity, while AlO and SiO nanoparticles had no effect. Amplicon sequencing revealed substantial shifts in bacterial community composition in soils amended with AgNPs, with significant decreases in the relative abundance of Acidobacteria and Verrucomicrobia and an increase in Proteobacteria. In particular, the relative abundance of the Proteobacterial genus Dyella significantly increased in AgNP amended soil. The effects of AlO and SiO NPs on bacterial community composition were less pronounced. AgNPs significantly reduced bacterial and archaeal amoA gene abundance in soil, with the archaea more susceptible than bacteria. AgNPs also significantly impacted soil fungal community structure, while AlO and SiO NPs had no effect. Several fungal ribotypes increased in soil amended with AgNPs, compared to control soil. This study highlights the need to consider the effects of individual nanoparticles on soil microbial communities when assessing their environmental impact.
土壤微生物是养分循环的关键贡献者，对于维持健康的土壤和可持续农业至关重要。尽管已经在体外对广泛的纳米颗粒物质的抗菌作用进行了描述，但对于这些化合物对土壤等环境中的微生物群落的影响知之甚少。在这项研究中，采用酶分析、分子指纹图谱和扩增子测序相结合的微宇宙实验，研究了三种广泛使用的纳米颗粒（银、二氧化硅和氧化铝）对农业牧草地土壤中细菌和真菌群落的影响。相对低浓度的银纳米颗粒（AgNPs）显著降低了土壤中总脱氢酶和脲酶的活性，而 AlO 和 SiO 纳米颗粒没有影响。扩增子测序揭示了 AgNPs 处理土壤中细菌群落组成的显著变化，其中酸杆菌和疣微菌的相对丰度显著降低，变形菌的相对丰度增加。特别是，变形菌属 Dyella 的相对丰度在 AgNP 处理的土壤中显著增加。AlO 和 SiO NPs 对细菌群落组成的影响则不那么明显。AgNPs 显著降低了土壤中细菌和古菌 amoA 基因的丰度，古菌比细菌更敏感。AgNPs 还显著影响了土壤真菌群落结构，而 AlO 和 SiO NPs 则没有影响。与对照土壤相比，添加 AgNPs 的土壤中几种真菌的核糖体类型增加。本研究强调了在评估其环境影响时需要考虑单个纳米颗粒对土壤微生物群落的影响。
