Impact and recovery of groundwater microbial communities exposed to manufactured nanomaterials (MNM).

本研究的总体目标是确定制造纳米材料（MNM）暴露对地下水中天然微生物群落的多样性和活动的影响，包括那些负责有机共污染物生物降解的微生物群落。为了解决以前发表的暴露研究的许多关键局限性，我们将采取更全面（比以前报道的研究），跨学科（环境微生物学家和材料科学家）和系统的方法来评估MNM对暴露地面微生物群落的毒性。首先，将合成和表征选定的MNM批次，以确认起始物料的性质（物理、化学状态和纯度）。这是通过采用现场材料科学家经常使用的一系列标准方法实现的（牛津材料表征服务http://www-omcs.materials.ox.ac.uk），包括XPS，UOS，FTIR和TEM。然后将这些材料引入实验室微观世界，由新鲜收集的地下水组成，历史上被农药（异丙隆）和常见的环境/工业污染物（三氯乙烯）污染，并在四个月的暴露期内确定土著微生物群落的反应。微生物种群相对丰度的变化将为了解群落对MNM暴露的影响提供依据。此外，在社区的生物转化地下水污染物的能力的变化将提供洞察细胞的生理状态（活动），并在社区的功能多样性的变化，以响应MNM。将采用分子微生物生态学和材料科学技术采集时间样本并进行分析，以确定暴露的微生物群落的反应和引入的MNM中的化学变化。这将包括对整个微生物群落进行基因指纹鉴定，以检测物种组成和群落结构的变化;进行代谢特征分析，以确定群落承担具体生化任务的能力的变化;以及监测污染物的衰减率。MNM评估将包括表面和界面分析。在一些研究中，MNM将被移除（在Fe使用磁铁的情况下），并检查由移除毒性应激引起的群落恢复。此外，我们还将储存DNA，以针对关键功能群体（在未来的研究中），如氨氧化物，它在氮循环，水质和生态系统功能中起着至关重要的作用，是生态系统健康的敏感指标。这是一个非常专业的过程，需要通过平行和未来的赠款申请进一步提供资金。概述的研究计划将通过相关项目的工作人员的投入，目前欧盟资助的奖学金和OCMS的实物支持来促进。所获得的信息将填补知识空白的证据基础的风险表征MNM，一个关键的必要条件ENI计划。该项目将大大有助于我们了解MNM化学如何影响微生物群落，以及MNM本身如何通过与环境和微生物本身的相互作用而改变。

The overall objective of this study is to determine the impact of manufactured nano-material (MNM) exposure on the diversity and activities of natural microbial communities in groundwaters, including those responsible for the biodegrdation of organic co-contaminants. In order to address many of the key limitations of previous published exposure studies, we will take a more comprehensive (than previously reported studies), cross-disciplinary (environmental microbiologists and material scientists) and systematic approach to assessing MNM toxicity towards exposed groundater microbial communities. Firstly, batches of selected MNM will be synthesised and characterised, to confirm the nature (physical, chemical state and purity) of the starting material. This achieved by employing a range of standard methods, routinely used by the material scientists on site (Oxford Material Characterisation Service http://www-omcs.materials.ox.ac.uk), including including XPS,UOS, FTIR and TEM. The materials will then be introduced to laboratory microcosms, composed of freshly collected groundwater, historically contaminated with pesticide (isoproturon) and a common environmental/industrial contaminant (trichoroethene), and the response of the indigenous microbial community determined over a four-month exposure period. Changes in the relative abundance of microbial populations will provide insight into the impact of the communities to MNM exposure. Furthermore, changes in the communities' ability to biotransform groundwater contaminants will provide insights into the physiological state of the cells (activity), and shifts in the functional diversity of the community in response to MNM. Temporal samples will be taken and analysed using molecular microbial ecology and material science techniques, to determine the response of exposed microbial communities and chemical changes in the introduced MNM. This will include genetic fingerprinting of the whole microbial community to detect shifts in species composition and community structure; metabolic profiling, to determine changes in the ability of the community to undertake specific biochemical tasks; and monitoring attenuation rates of the pollutant. MNM assessment will include surface and interface analysis. In some studies MNM will be removed (in the case of Fe using magnets) and the recovery of the community caused by the removal of toxic stress examined. In addition, we will store the DNA to target key functional populations (in future studies) such as ammonium oxidisers, which play a vital role in nitrogen cycling, water quality and ecosystem functioning and are sensitive indicators of ecosystem health. This is a very specialist process and will require further funding via parallel and future grant applications. The programme of research outlined will be facilitated by input by staff on related projects, a current EU-funded studentship and in-kind support from OCMS. The information obtained will fill knowledge gaps in the evidence base for risk characterisation of MNM, a key requisite for the ENI programme. The project will significantly contribute to our understanding of how MNM chemistry influences microbial communities, and how MNM themselves will alter by their interaction with the environment and microbes themselves.