Nitrification Inhibition by Silver Nanoparticles

银纳米颗粒对硝化的抑制

• 批准号: 0650943
• 负责人: Zhiqiang Hu
• 金额: --
• 依托单位: University of Missouri-Columbia
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-06-01 至 2009-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0650943&HistoricalAwards=false
• 关键词: Nitrification; Inhibition; Silver; Nanoparticles

CBET-0650943Zhiqiang HuUniversity of Missouri-ColumbiaNitrification inhibition by silver nanoparticlesSilver nanoparticles are emerging as one of the fastest growing nanomaterials with wide applications. Because of their unique quantum size effects, nanoparticles present vastly different properties from those of bulk materials including enhanced reactivity and greater ability to penetrate cell membranes. Currently, little is known about the adverse effects of silver nanoparticles to human health and their fate in ecological systems. Nitrification involving ammonium oxidation to nitrite and nitrate is an important biological process in both natural and engineered systems, and nitrifying bacteria could serve as potential environmental health indicators because of their extreme sensitivity to metal toxins. In view of the above considerations and building on their experience in nitrification and fluorescence microscopy, the investigators are proposing an exploratory experimental research on nitrification inhibition by silver nanomaterials. In this research, silver nanoparticles will be prepared by chemical reduction and characterized via UV/Vis spectrophotometry and electron microscopy. The detrimental effects of the nanoparticles on nitrification kinetics and microbial energetics at various silver concentrations will be quantified using extant respirometry. The size- and shape-dependent luminescent behavior of silver nanoparticles and their extracellular and/or intracellular location will be analyzed by two-photon laser scanning fluorescence microscopy. Cell membrane integrity will be evaluated based on nucleic acid staining and surface-enhanced fluorescence in the presence of silver nanoparticles. With the support from NSF, this exploratory research will lead to a better understanding of nanoparticle-microbe interactions and shed light on the fundamental mechanisms of nitrification inhibition by emerging metallic nanomaterials.

CBET-0650943胡志强密苏里大学-哥伦比亚分校银纳米粒子对硝化作用的抑制银纳米粒子正在成为发展最快、应用广泛的纳米材料之一。由于其独特的量子尺寸效应，纳米颗粒呈现出与块状材料截然不同的特性，包括增强的反应性和更强的穿透细胞膜的能力。目前，人们对银纳米颗粒对人类健康的不利影响以及它们在生态系统中的命运知之甚少。在自然和工程系统中，氨氧化为亚硝酸盐和硝酸盐的硝化作用都是一个重要的生物过程，而硝化细菌由于其对金属毒素的极端敏感性，可以作为潜在的环境健康指标。基于上述考虑，并借鉴他们在硝化作用和荧光显微镜方面的经验，研究人员提出了一项关于银纳米材料抑制硝化作用的探索性实验研究。本研究采用化学还原法制备银纳米粒子，并通过紫外-可见光谱和电子显微镜对其进行表征。纳米颗粒在不同银浓度下对硝化动力学和微生物能量学的不利影响将使用现有的呼吸测量法进行量化。双光子激光扫描荧光显微镜将分析银纳米粒子的尺寸和形状依赖的发光行为以及它们在细胞外和/或细胞内的位置。在银纳米粒子存在的情况下，将基于核酸染色和表面增强荧光来评估细胞膜的完整性。在NSF的支持下，这项探索性研究将有助于更好地了解纳米颗粒与微生物的相互作用，并揭示新兴金属纳米材料抑制硝化的基本机制。