School of Materials and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou, China; Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, Zhengzhou University of Light Industry, Zhengzhou, China.
School of Materials and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou, China.
Sci Total Environ. 2020 Jul 10;725:138340. doi: 10.1016/j.scitotenv.2020.138340. Epub 2020 Apr 3.
To explore the chronic phototoxicity of ZnO nanoparticles (NPs) on stream ecosystems, a microcosm experiment was conducted on Populus nigra L. leaf decomposition with ZnO NPs under different light components (visible and ultraviolet (UV) light) with a natural photoperiod. Light components significantly affected the transformation dynamic of ZnO NPs. After chronic exposure (day 15 to 30), ZnO NPs under light irradiation caused significant decrease in the microbial biomass, but significant increase in the fungal biomass. Compared to visible light, UV light led to lower microbial biomass and metabolic activity but higher antioxidant activity when ZnO NP concentrations were 10 and 20 mg L, eventually causing significant reductions in decomposition rates. Pleosporales sp., Montagnulaceae sp., and Volutella citronella responded sensitively to ZnO NPs. However, higher decomposition efficiency of leaf nitrogen was achieved under UV light when ZnO NPs concentrations were 10 mg L, suggesting that microbial nitrogen-related enzymes and ZnO nanoparticle photocatalytic properties contribute to leaf degradation. In conclusion, the results of this study provide compelling evidence that light components strongly affect ZnO NPs transformation, which impacts microbial communities with consequences for ecological processes in stream ecosystems.
为了探究 ZnO 纳米颗粒（NPs）对河流生态系统的慢性光毒性，本研究采用微宇宙实验，在自然光周期下，用 ZnO NPs 处理黑杨叶片分解，研究不同光照成分（可见光和紫外光（UV））对 ZnO NPs 转化动态的影响。光照成分对 ZnO NPs 的转化动态有显著影响。经过慢性暴露（第 15 天至 30 天），光照下的 ZnO NPs 导致微生物生物量显著减少，但真菌生物量显著增加。与可见光相比，当 ZnO NP 浓度为 10 和 20 mg/L 时，紫外光导致微生物生物量和代谢活性降低，但抗氧化活性升高，最终导致分解率显著降低。Pleosporales sp.、Montagnulaceae sp. 和 Volutella citronella 对 ZnO NPs 敏感。然而，当 ZnO NPs 浓度为 10 mg/L 时，紫外光下叶片氮的分解效率更高，这表明微生物氮相关酶和 ZnO 纳米颗粒光催化特性有助于叶片降解。总之，本研究结果有力地证明了光照成分对 ZnO NPs 转化有强烈影响，这会影响微生物群落，进而影响河流生态系统中的生态过程。
