Evaluating Beneficial Bacteria Function Following Engineered Nanoparticle Exposure

化学系的环境化学科学(ECS)计划将支持明尼苏达大学克里斯蒂·海恩斯教授的研究计划。海恩斯教授和她的学生将研究有益细菌与工程纳米颗粒的相互作用，并评估模拟天然水对纳米颗粒特性和细菌影响的作用。最初的努力将集中在通过研究纳米颗粒在天然有机物(NOM)存在下的分散性和稳定性来表征纳米颗粒在模拟自然水中的行为，同时也致力于了解纳米颗粒引入NOM后的变化。为了进一步从机理上理解细菌-纳米颗粒的相互作用，下一阶段的研究将解决纳米颗粒的存在如何影响金黄色葡萄球菌的功能，即生物膜的形成和黄素分泌。这些功能对生态系统有许多建设性的影响，纳米颗粒的破坏将是巨大的。这项研究解决了围绕常用的工程纳米颗粒与有益细菌S.onedensis相互作用的生态毒性知识的关键差距。被选中进行研究的纳米粒子，二氧化钛和银，很可能是无意中释放到水生生态系统中的候选者，因为它们在消费产品中普遍使用。在食物网络中，基于细菌本身的结构功能以及它们与其他生物体的相互作用，工程纳米颗粒与有益细菌的相互作用是重要的。因此，至关重要的是要考虑这些纳米材料如何影响具有重要生态意义的生物体。单胞菌是一种理想的有益细菌模型，因为它们在地理上和整个水生生态系统中分布广泛。作为该项目的一部分，海恩斯教授和她的学生将开展一项名为“卤虾中的纳米颗粒毒性”的高中实验室活动，在那里，学生们将获得实践经验，研究贵金属纳米颗粒对水生无脊椎动物的影响。他们将从化学、微生物学和统计学中学习概念，同时探索这一前沿话题。该研究项目将为学生提供极好的教育机会，包括一些来自代表人数不足的群体的学生，他们希望在环境科学的前沿工作。

The Environmental Chemical Sciences (ECS) program of the Division of Chemistry will support the research program of Prof. Christy Haynes of the University of Minnesota. Prof. Haynes and her students will study the interaction of beneficial bacteria with engineered nanoparticles and assess the role that simulated natural water has on nanoparticle characteristics and bacterial impact. Initial efforts will focus on characterizing nanoparticle behavior in simulated natural water by studying nanoparticle dispersity and stability in the presence of natural organic matter (NOM) while also working to understand transformations the NOM experiences after nanoparticle introduction. Furthering mechanistic understanding of bacteria-nanoparticle interactions, the next stage of the study will address how nanoparticle presence influences S. oneidensis function, namely biofilm formation and flavin secretion. These functions have numerous constructive impacts on the ecosystem, and disruption by nanoparticles would be significant. The study addresses the critical gap in ecological toxicity knowledge surrounding the interaction of commonly used engineered nanoparticles and the beneficial bacteria, S. oneidensis. The nanoparticles chosen for investigation, TiO2 and Ag, are likely candidates for unintentional release into the aquatic ecosystem because of their common use in consumer products. Within the food web, the interaction of engineered nanoparticles with beneficial bacteria is important based on the constructive function of bacteria itself as well as their interaction with other organisms. It is critical, therefore, to consider how ecologically important organisms are impacted by these nanomaterials. S. oneidensis is an ideal model beneficial bacteria because they are widely distributed, geographically and throughout the aquatic ecosystem. As a part of the project, Prof. Haynes and her students will develop a high school laboratory activity titled, "Nanoparticle Toxicity in Brine Shrimp" where students will get a hands-on experience examining the effects of noble metal nanoparticles on an aquatic invertebrate. They will learn concepts from chemistry, microbiology, and statistics, while exploring this cutting edge topic. The research project will provide excellent educational opportunities for students, including some from underrepresented groups, desiring to work at the forefront of environmental science.