To investigate effects of engineered nanoparticles (ENPs) at environmentally relevant concentrations to aquatic microbial communities, TiO₂ at 700 µg/L and ZnO at 70 µg/L were spiked to river water samples either separately or combined. Compared to controls where no ENPs were added, the addition of TiO₂ ENPs alone at the tested concentration had no statistically significant effect on both the bacterial and eukaryotic communities. The presence of added ENPs: ZnO or ZnO + TiO₂ led to significant shift of the microbial community structure and genus distribution. This shift was more obvious for the bacteria than the eukaryotes. Based on results from single particle – inductively coupled plasma – mass spectrometry (SP-ICP-MS), all ENPs aggregated rapidly in water and resulted in much larger particles sizes than the original counterparts. “Dissolved” (including particles smaller than the size detection limits and dissolved ions) concentrations of Ti and Zn increased, too in treatment groups vs. the controls.

中文翻译：

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TiO ₂和ZnO纳米颗粒对水生微生物群落的影响：在与环境有关的浓度下的影响

为了研究环境相关浓度的工程化纳米颗粒（ENP）对水生微生物群落的影响，将700 µg / L的TiO ₂和70 µg / L的ZnO分别加标到河水样品中。与没有添加ENP的对照相比，以测试浓度单独添加TiO ₂ ENP对细菌和真核生物均无统计学意义的影响。存在添加的ENP：ZnO或ZnO + TiO ₂导致微生物群落结构和属分布发生重大变化。对于细菌而言，这种转变比真核生物更为明显。根据单颗粒电感耦合等离子体质谱（SP-ICP-MS）的结果，所有ENP在水中迅速聚集，并产生了比原始对应物大得多的粒径。与对照组相比，治疗组的“溶解”（包括小于尺寸检测极限的颗粒和溶解的离子）的钛和锌浓度也增加了。