RUI: Developing a regression model predicting the toxicity of metal nanoparticles against soil microbial community

活跃多样的微生物群落对土壤至关重要；因此对农业、粮食安全和生态系统健康也是如此。这些群落的变化可以显著影响土壤质量、健康和生产力。本研究使用实验和统计/建模方法来调查和预测常见的金属纳米颗粒（铁、铜和银）对土壤微生物群落的影响，这些纳米颗粒据报道具有抗微生物特性。主要的研究目标是开发模型，帮助评估普通金属纳米颗粒的生态毒性，而不必为每个待测样品进行大量的实验。这项工作通过结合实验/建模方法实现了这一目标。实验包括十个重要的土壤参数（pH值、温度、纳米颗粒浓度、有机碳含量、土壤湿度，以及各种阳离子和阴离子（如Na、Ca、Mg、硝酸盐和磷酸盐）的浓度）对选定的商业购买的纳米颗粒与两种模型土壤相互作用的毒性研究，每种土壤都有其独特的微生物群落，将在微观环境中进行。纳米颗粒对微生物群落的毒性将使用三种不同的微生物健康和代谢活性指标进行评估：PCR-DGGE、Biolog Ecoplates和总土壤FAME分析，从中可以确定单个生态毒性值。实验矩阵的结果将用于开发线性回归模型，该模型将确定环境参数的增加，减少或对土壤微生物的毒性没有影响。将开发二次回归，以建立线性模型的结果来预测每个参数的毒性潜力，并确定和评估各种环境参数之间的相互作用。该研究的广泛影响包括研究与教育的紧密结合，吸引大量本科生参与环境生物学研究，并利用研究来充实本科课程。通过夏季研究经验，该项目还将吸引来自南方大学的学生，这是一所历史悠久的黑人大学，仍在从卡特里娜飓风的影响中恢复过来。通过招募道林学院少数民族教师发展和培训项目中心的学生参与研究，还将增加在科学领域未被充分代表的群体的参与。为提高公众对其对环境的影响的认识，还将提供免费的公开讲座。

Active and diverse microorganism communities are essential for soil; and hence for agriculture, food security, and ecosystem health. Changes in these communities can significantly influence soil quality, health, and productivity. This research uses experimental and statistical/modeling approaches to investigate and predict the impact of common metal nanoparticles (iron, copper, and silver), which are reported to have anti-microbial properties, on soil microbial communities. The main research goal is to develop models that can help assess the ecotoxicity of common metal nanoparticles without having to resort to carrying out large numbers of experiments for each sample to be tested. This work accomplishes that goal with a combined experimental/modeling approach. Experiments involving the study of the toxicity of ten important soil parameters (pH, temperature, nanoparticle concentration, organic carbon content, soil moisture, and the concentration of various cations and anions like Na, Ca, Mg, nitrates, and phosphates) on the interaction between selected commercially purchased nanoparticles and two model soils, each with their unique microbial community, will be carried out in microcosms. The toxicity of the nanoparticles to microbial communities will be evaluated using three different indicators of microbial health and metabolic activity: PCR-DGGE, Biolog Ecoplates, and total soil FAME analyses from which a single ecotoxicity value can be determined. Results of the experimental matrix will be used to develop a linear regression model that will identify environmental parameters that increase, decrease, or have no influence on toxicity on the soil microbes. A quadratic regression will be developed that build off the results of the linear model to predict the toxic potential of each parameter and identify and assess interactions among the various environmental parameters. Broader impacts of the research include the strong integration of research and education, engaging large numbers of undergraduate students in environmental biology research, and using the research to augment undergraduate course curriculum. Through a summer research experience, the project will also engage students from Southern University, a historically black college that is still recovering from the effects of Hurricane Katrina. Participation of under-represented groups in the sciences will also be increased by recruiting students from the Dowling College Center for Minority Teacher Development and Training Program to participate in the research. Free public lectures tailored for the general public to increase their awareness of their impacts on the environment will also be presented.