Evidence for Negative Effects of TiO2 and ZnO Nanoparticles on Soil Bacterial Communities

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• 作者：Yuan Ge ; Joshua P. Schimel ; Patricia A. Holden
• 刊名：Environmental Science & Technology
• 出版年：2011
• 出版时间：February 15, 2011
• 年：2011
• 卷：45
• 期：4
• 页码：1659-1664
• 全文大小：860K
• 年卷期：v.45,no.4(February 15, 2011)
• ISSN：1520-5851

文摘

Increased use of engineered nanoparticles (ENPs) raises concerns about their environmental impacts, but the effects of metal oxide ENPs on environmental processes and the organisms that carry them out remain largely unknown. This study evaluated the impacts of TiO₂ and ZnO ENPs on soil bacterial communities. Soils collected from a California grassland were exposed to different doses of nanoparticulate TiO₂ (0, 0.5, 1.0, and 2.0 mg gp>鈭?p> soil) and ZnO (0.05, 0.1, and 0.5 mg gp>鈭?p> soil) in microcosms over 60 days. The effects on soil microbial biomass were assessed by substrate induced respiration (SIR) and total extractable soil DNA. The effects on bacterial community composition were evaluated by terminal restriction fragment length polymorphism (T-RFLP) analysis. Total soil respiration indicated impacts on overall microbial activity. We found that both nano-TiO₂ and nano-ZnO reduced both microbial biomass (as indicated by declines in both SIR and DNA) and diversity (by T-RFLP). Both types of nanoparticles also altered the composition of the soil bacterial community. The effect of nano-ZnO was stronger than that of nano-TiO₂, as reflected by lower DNA and stronger shifts in bacterial community composition for nano-ZnO at the same exposure concentration (0.5 mg gp>鈭?p> soil). Thus, nanoparticulate metal oxides may measurably and negatively impact soil bacterial communities.