Battin Tom J, Kammer Frank V D, Weilhartner Andreas, Ottofuelling Stephanie, Hofmann Thilo
Department of Freshwater Ecology, University of Vienna, Vienna 1090, Austria.
Environ Sci Technol. 2009 Nov 1;43(21):8098-104. doi: 10.1021/es9017046.
Industry has already commenced the large-scale production of some nanomaterials. Evidence for toxic effects of engineered nanoparticles (ENP) on model organisms is increasing. However, in order to assess the consequences of environmental hazards, a better understanding is required of the behavior of ENP in aquatic ecosystems and their impact on complex communities. In this research, through experimenting with different TiO(2) nanoparticles in stream microcosms, we have shown that microbial membranes were significantly compromised, even under ambient ultraviolet radiation and nano-TiO(2) concentrations predicted for surface waters. Our results suggest adverse effects are not necessarily only attributable to individual particles smaller than 100 nm but also to low concentrations of larger, naturally agglomerating TiO(2) nanoparticles. Cell membrane damage was more pronounced in free-living cells than in biofilm cells, indicating the protective role of cell encapsulation against TiO(2) nanoparticles. The generation of intracellular reactive oxygen species (ROS) further suggests nano-TiO(2)-induced effects inside the microbial cells. Our findings indicate a high sensitivity of microbial communities to levels of ENP concentration that are to be expected in the environment, with as yet unknown implications for the functioning and health of ecosystems.
工业已经开始大规模生产某些纳米材料。工程纳米颗粒（ENP）对模式生物产生毒性作用的证据越来越多。然而，为了评估环境危害的后果，需要更好地了解ENP在水生生态系统中的行为及其对复杂群落的影响。在本研究中，通过在溪流微观世界中对不同的二氧化钛纳米颗粒进行实验，我们发现即使在环境紫外线辐射和预测的地表水纳米二氧化钛浓度下，微生物膜也会受到显著损害。我们的结果表明，不利影响不一定仅归因于小于100纳米的单个颗粒，也可能归因于低浓度的较大的、自然团聚的二氧化钛纳米颗粒。与生物膜细胞相比，游离细胞中的细胞膜损伤更为明显，这表明细胞包裹对二氧化钛纳米颗粒具有保护作用。细胞内活性氧（ROS）的产生进一步表明了纳米二氧化钛在微生物细胞内诱导的效应。我们的研究结果表明，微生物群落对环境中预期的ENP浓度水平高度敏感，对生态系统的功能和健康的影响尚不清楚。
