Fate of per- and poly-fluoroalkyl Substances (PFASs) in soils affected by plant and rhizosphere microbial community

全氟烷基和多氟烷基物质（PFAS）代表了一类在工业中广泛使用的超过3，000种合成化合物。PFAS在人类、饮用水、土壤、植物和野生动物中的检出率越来越高。这些发现引起了人们的严重关注，因为PFAS具有持久性，因此会在环境中积累。PFAS与癌症发病率增加、干扰胆固醇代谢和破坏人类内分泌功能有关。全氟辛烷磺酸的一个主要环境来源是在灭火活动和训练演习中释放的水性成膜泡沫。一旦AFFF被释放到土壤中，PFAS就可以被土壤中的微生物吸收并潜在地转化。虽然这可以导致PFAS从土壤中去除，但对PFAS在根际环境中的命运知之甚少（即，植物根部周围的土壤）。其中最主要的问题是植物，土壤微生物或两者是否负责生物降解。本项目的重点是回答这些问题，并确定哪些因素控制的转化过程。更好地了解控制PFAS在土壤中的命运的机制，将能够开发具有成本效益的PFAS污染土壤的修复技术。这项工作的结果将形成一个教育推广计划的基础，重点是代表性不足的群体，以增加国家的STEM劳动力的多样性。这项研究的目标是确定影响全氟和多氟烷基物质（PFAS）在土壤中的命运的关键因素，以制定有效的战略，以减轻PFAS土壤污染的风险。本研究的重点是阐明土壤微生物、植物及其根系分泌物的作用，以及植物与土壤微生物之间的协同作用对PFAS在土壤中的归宿的影响。具体的研究目标是：i）确定土壤微生物群在AFFF影响的土壤中PFAS生物转化中的作用; ii）研究根系分泌物对土壤中PFAS命运的相互影响; iii）研究植物/细菌协同作用对土壤中PFAS生物转化的潜在影响。该研究结果将为深入了解根际和非根际微生物介导PFAS生物转化的机制提供基础。这项研究将提供深入了解有效的植物修复策略，减轻PFAS污染的土壤。一个有效的处理策略，整合植物及其相关微生物群落的知识将是一个科学突破，导致减少PFAS及其潜在的前体从环境中。拟议的研究作为一个肥沃的土壤，研究生和本科生在微生物学，植物科学和环境工程的接口跨学科培训。更广泛的影响将来自参与和推广到代表性不足的群体，向科学界传播研究成果，以及在地方，国家和/或国际会议上的演讲。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

Per- and polyfluoroalkyl substances (PFAS) represent a class of over 3,000 synthetic compounds that have been widely used in industry. PFASs are increasingly detected in humans, drinking water, soils, plants, and wildlife. These findings have raised significant concern because PFASs are persistent thus accumulate in the environment. PFAS have been implicated in increased cancer rates, interference with cholesterol metabolism, and disruption of endocrine function in humans. A major environmental source of PFASs are aqueous film-forming foams (AFFFs) released during fire-fighting events and training exercises. Once AFFFs are released to soils, PFAS can be taken up and potentially transformed by microorganisms in the soil. While this can lead to removal of PFAS from soil, much is not known about the fate of PFAS in the rhizosphere environment (i.e., the soil around plant roots). Primary among these is the question whether plants, soil microbes, or both are responsible for the biodegradation. The focus of this project is to answer these questions and identify which factors control the transformation processes. Better understanding of the mechanisms controlling the fate of PFAS in soils will enable the development of cost-effective remediation technologies for PFAS-contaminated soils. Results from this work will form the basis of an educational outreach program focused on under-represented groups to increase the diversity of the Nation's STEM workforce.The goal of this study is to identify key factors affecting the fate of per- and polyfluoroalkyl substances (PFAS) in soils for the development of effective strategies to mitigate risks of PFAS soil contamination. The focus of the proposed study is to delineate the roles of soil microbes, plants and their root exudates, and the synergic interactions between plants and soil microbes on the fate of PFAS in soils. The specific research objectives are to: i) determine the role of soil microbiota in PFAS biotransformation in AFFF-impacted soils; ii) investigate the reciprocal impacts of root exudates on the fate of PFAS in soils; and iii) examine the potential effects of plant/bacterial synergisms in PFAS biotransformation in soils. The results of the proposed study will advance fundamental knowledge on the underlying mechanism mediating PFAS biotransformation by both rhizosphere and non-rhizosphere associated microbes. This research will provide insight into effective phytoremediation strategies for mitigating PFAS contamination in soils. An effective treatment strategy that integrates knowledge of both plants and their associated microbial communities would be a scientific breakthrough, leading to the reduction of PFAS and their potential precursors from the environment. The proposed research serves as a fertile ground for interdisciplinary training of graduate and undergraduate students at the interface of microbiology, plant science, and environmental engineering. Broader impacts will result from the engagement and outreach to under-represented groups, dissemination of research results to the scientific community, and from presentations at local, national and/or international conferences.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.