comparative toxicity of nanoparticulate cuo and zno to soil bacterial communities比较毒性nanoparticulate错和氧化锌土壤细菌社区.pdfVIP

Comparative Toxicity of Nanoparticulate CuO and ZnO to Soil Bacterial Communities 1,2 1 3 1 Johannes Rousk *, Kathrin Ackermann , Simon F. Curling , Davey L. Jones 1 Environment Centre Wales, Bangor University, Gwynedd, United Kingdom, 2 Section of Microbial Ecology, Department of Biology, Lund University, Lund, Sweden, 3 BioComposites Centre, Bangor University, Gwynedd, United Kingdom Abstract The increasing industrial application of metal oxide Engineered Nano-Particles (ENPs) is likely to increase their environmental release to soils. While the potential of metal oxide ENPs as environmental toxicants has been shown, lack of suitable control treatments have compromised the power of many previous assessments. We evaluated the ecotoxicity of ENP (nano) forms of Zn and Cu oxides in two different soils by measuring their ability to inhibit bacterial growth. We could show a direct acute toxicity of nano-CuO acting on soil bacteria while the macroparticulate (bulk) form of CuO was not toxic. In comparison, CuSO4 was more toxic than either oxide form. Unlike Cu, all forms of Zn were toxic to soil bacteria, and the bulk-ZnO was more toxic than the nano-ZnO. The ZnSO4 addition was not consistently more toxic than the oxide forms. Consistently, we found a tight link between the dissolved concentration of metal in solution and the inhibition of bacterial growth. The inconsistent toxicological response between soils could be explained by different resulting concentrations of metals in soil solution. Our findings suggested that the principal mechanism of toxicity was dissolution of metal oxides and sulphates into a metal ion form known to be highly toxic