Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, China.
Int J Environ Res Public Health. 2019 Nov 21;16(23):4639. doi: 10.3390/ijerph16234639.
Nanoplastic (NP) contamination is becoming a pervasive issue as NPs, originating from microplastic particles, pose potentially harmful environmental impacts on aquatic ecosystems. The environmental hazards of NPs on microorganisms have been well documented in recent studies; however, little is known about their ecotoxicity effects on freshwater biofilms, which serve as important primary producers and decomposers and are highly connected with other ecosystem components. We investigated the effects of NPs on the microbial metabolic functions of freshwater biofilms in terms of carbon source utilization ability. Biofilm samples were collected, cultivated in a hydrodynamic flume for six weeks, and then exposed in polystyrene (PS) beads (100 nm in size) with different NP concentrations (1, 5, and 10 mg/L). BIOLOG ECO microplates were used to quantify carbon source utilization characteristics. The data were analyzed using average well-color development (AWCD), functional diversity indices, and principle component analysis (PCA). Results showed that the total carbon metabolic functions (represented by AWCD) remained constant ( > 0.05) with elevated NP concentrations, but some specific carbon sources (e.g., esters) changed in their utilization ability ( < 0.05). The microbial functional diversity (Shannon-Wiener diversity index, Simpson diversity index, and Shannon evenness index) was significantly reduced under 10 mg/L NPs ( < 0.05), indicating an inhibiting effect of NPs on biofilm metabolic diversity. This study examined NP ecotoxicity effects on microbial metabolic activities at the community level, but further studies are required to fully understand the mechanisms driving this change.
纳米塑料（NP）污染日益严重，因为源于微塑料颗粒的 NP 可能对水生生态系统造成潜在的有害环境影响。最近的研究已经充分记录了 NP 对微生物的环境危害；然而，对于 NP 对淡水生物膜的生态毒性影响，我们知之甚少，因为生物膜作为重要的初级生产者和分解者，与其他生态系统成分高度相关。我们研究了 NP 对淡水生物膜微生物代谢功能的影响，特别是对碳源利用能力的影响。采集生物膜样本，在水动力水槽中培养六周，然后用不同 NP 浓度（1、5 和 10 mg/L）的聚苯乙烯（PS）珠（粒径 100nm）暴露。使用 BIOLOG ECO 微孔板定量碳源利用特性。使用平均颜色发展（AWCD）、功能多样性指数和主成分分析（PCA）分析数据。结果表明，总碳代谢功能（以 AWCD 表示）在升高的 NP 浓度下保持不变（>0.05），但一些特定碳源（例如酯类）的利用能力发生了变化（<0.05）。在 10mg/L NP 下，微生物功能多样性（香农-威纳多样性指数、辛普森多样性指数和香农均匀度指数）显著降低（<0.05），表明 NP 对生物膜代谢多样性具有抑制作用。本研究考察了 NP 对微生物代谢活性的生态毒性效应在群落水平上，但需要进一步研究以充分了解驱动这种变化的机制。
