College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
Environ Sci Technol. 2011 Jul 15;45(14):6032-40. doi: 10.1021/es2010573. Epub 2011 Jun 28.
This is the first study investigating the toxicity of nanoparticles (NPs) to algae in the presence of dissolved organic matter (DOM). Suwannee river fulvic acid (SRFA), a type of DOM, could significantly increase the toxicity of CuO NPs to prokaryotic alga Microcystis aeruginosa. Internalization of CuO NPs was observed for the first time in the intact algal cells using high resolution transmission electron microscopy (HRTEM), and the cell uptake was enhanced by SRFA. A fast Fourier transformation (FFT)/inversed FFT (IFFT) process revealed that a main form of intracellular NPs was Cu(2)O, and an intracellular environment may reduce CuO into Cu(2)O. The internalization behavior alone did not seem to pose a hazard to membrane integrity as shown from the flow cytometry data. Elevated CuO nanotoxicity by SRFA was related to a combination of a lesser degree of aggregation, higher Cu(2+) release, and enhanced internalization of CuO NPs.
这是首次研究在溶解有机质（DOM）存在的情况下纳米颗粒（NPs）对藻类的毒性。苏万尼河富里酸（SRFA）是一种 DOM，可显著增加氧化铜纳米颗粒（CuO NPs）对原核藻类铜绿微囊藻的毒性。利用高分辨率透射电子显微镜（HRTEM）首次观察到 CuO NPs 在完整藻类细胞中的内化，并且 SRFA 增强了细胞摄取。快速傅里叶变换（FFT）/逆快速傅里叶变换（IFFT）过程表明，细胞内 NPs 的主要形式是 Cu2O，并且细胞内环境可能将 CuO 还原为 Cu2O。如流式细胞术数据所示，内化行为本身似乎不会对膜完整性造成危害。SRFA 增强的 CuO 纳米毒性与聚集度降低、Cu2+释放增加和 CuO NPs 内化增强有关。
