Interaction of Nanoparticles with Microbal Populations during Particle Transport

皇家学会和皇家工程师学会的报告以及NRCG已经确定有必要研究将人造纳米颗粒引入微生物群落及其环境系统。因此，必须探索现有的方法和技术，以帮助回答所提出的一些研究目标。我们建议评估一套可以在未来研究中使用的技术，以扩大我们对纳米颗粒可能产生的影响的了解。被测试的微生物菌株将具有不同的细胞壁结构(革兰氏阳性和革兰氏阴性)，来自不同的环境，如人体肠道、土壤和自然水道。选择纳米粒子涂层是因为它们的疏水和亲水特性，这些涂层与微生物之间的相互作用将使用显微光谱和荧光团标记进行观察。纳米粒子涂层对单个微生物细胞及其分裂的影响将使用拉曼光谱技术进行研究。拉曼镊子将被用来分离单个细胞，以分析与纳米颗粒接触后的具体变化。用荧光团标记纳米颗粒将使它们能够在运输过程中进行跟踪，以及它们在多孔介质床内的细胞或矿物表面上的积累。该床将由清洁的石英组成，石英是一种存在于许多土壤、沉积物和地下水环境中的矿物。预期的结果是1)对纳米颗粒传输、摄取和对细胞生长的影响的同步体外/体内研究技术进行评估，2)对疏水和亲水纳米颗粒对选定的遗传多样性细菌的相对影响进行初步评估，以及3)评估扩大到实验室规模的填充床的范围，这些填充床的长度(30厘米)与土柱的长度相同。实验设计将结合研究人员在多孔颗粒介质中的颗粒传输和生物膜形成、制造的纳米颗粒的功能化以实现选定的表面化学性质以及共聚焦拉曼显微光谱的应用方面的经验。该项目的总体目标是为纳米颗粒表面改性及其与微生物和自然环境的相互作用方面的工作提供一个平台。有一支强大的团队可以实现这些愿望，他们拥有多个不同学科的强大个人专业知识，从使用显微光谱学、纳米颗粒生产到污染物对微生物群落的毒性。在牛津大学和阿普尔顿实验室团队以及谢菲尔德细胞矿物方案的帮助下，更广泛的支持基础设施也与该项目非常相关。这一概念验证项目有可能影响与纳米颗粒相关的许多不同领域的研究及其对自然系统的影响，并将有助于为这一领域的进一步研究提供坚实的平台。

The Royal Society and Royal Academy of Engineers report and the NRCG have identified the need for study into the introduction of anthropogenic nanoparticles into microbial communities and their environmental systems. Therefore it is essential to explore the methods and techniques available that could help to answer some of the research objectives put forward. We propose to evaluate a suite of techniques that could be used in future studies to broaden our knowledge about the impacts nanoparticles may have. The microbial strains tested will have differing cell wall structures (gram-positive versus gram negative) and originate from different environments such as the human gut, the soil and natural waterways. Nanoparticle coatings will be chosen for their hydrophobic and hydrophilic characteristics and the interaction between these coatings and the microbes will be observed using microspectroscopy and fluorophore labels. The influence of nanoparticle coatings on individual microbe cells and their division will be investigated using Raman spectroscopy techniques. Raman tweezers will be used to isolate individual cells to analyse specific changes after coming in contact with the nanoparticles. Labelling nanoparticles with fluorophores will enable their tracking as they are transported as well as their accumulation on cells or mineral surfaces within a porous medium bed. This bed will be composed of clean quartz which is a mineral present in many soil, sediment and groundwater environments. The anticipated results are 1) an evaluation of the techniques for the simultaneous in vitro/in vivo study of nanoparticle transport, uptake and affects on cell growth, 2) an initial assessment of the relative effect of hydrophobic and hydrophilic nanoparticles on selected genetically diverse bacteria and 3) an assessment of the scope for experimental upscaling to the bench-scale packed beds with lengths (30cm) of the same order as a soil column. The experimental design is to combine the investigators' experience on particle transport and biofilm formation in porous granular media, the functionalisation of manufactured nanoparticles to achieve selected surface chemical properties and application of Confocal Raman Microspectroscopy. The overall aim of the project is to provide a platform for work on aspects of nanoparticles surface modification and their interaction with microbes and the natural environment. There is a strong team available to realise these aspirations with strong individual expertise across a number of different disciplines ranging from the use of microspectroscopy, nanoparticle production and the toxicity of pollutants to microbial communities. The wider support infrastructure is also very relevant to the project with help from the Oxford and Appleton laboratory teams as well as the Sheffield cell-mineral programme. This proof-of-concept project has the potential to influence many different areas of research connected to nanoparticles and their effects on natural systems, and will help to provide a solid platform for further research across this area.