Enhancing the understanding of microbial transformation of polyfluoroalkyl chemicals and microbial defluorination

全氟烷基和多氟烷基物质（PFAS）广泛存在于土壤和沉积物、地表水和地下水以及我们的饮用水系统中。PFASs，特别是来自水成膜泡沫（AFFFs）的PFASs，对地下水水质是一个重大的和持续的威胁。由于在加拿大商业使用的数千种PFAS中只有少数受到监管，环境和公共卫生保护机构正在紧急收集所需的数据，以解决与许多PFAS相关的安全和监管问题。世界各地受影响的社区正在寻找有效的解决方案，以修复受污染的土壤和水系统。尽管在其结构中存在多个C-F键，但大多数多氟烷基化学品可以进行生物转化，甚至脱氟。转化产物被发现是复杂的;有些是持久性的，而另一些是剧毒的。未能识别和监测许多转化产物可能导致PFASs对环境影响的极大不确定性。因此，要制定有效的策略，管理和修复数以千计的PFAS污染的网站，提高认识的转化途径存在于微生物系统是必要的。必须探索微生物的特性、多样性和丰富性，以及负责这种转化的功能基因。** 研究的总体目标是阐明微生物分解多氟烷基化学品中C-F的新过程和机制，并发现此类微生物的多样性和身份。我的小组工作的一个主要重点是通过使用模型PFASs的实验工作建立新的生物转化规则，并开发可用于阐明环境中检测到的数百种PFASs的环境命运的预测能力。同时，我们将使用混合和纯细菌培养来研究“一碳去除途径”的机制和局限性，微生物用于PFAS的脱氟。我们还将致力于通过一种不依赖于培养的稳定同位素探测技术，鉴定参与降解环境中多氟烷基化学品的微生物。将环境化学与微生物学相结合的跨学科研究对于深入了解PFASs与微生物或酶的相互作用是必要的。拟议的研究计划将优先采用综合多学科方法和协作培训环境对HQP进行培训。 至少1名博士后，2名博士，2个硕士和5个本科生将通过该计划接受培训，并获得工程和应用科学新兴领域的加拿大劳动力所需的技能和愿景。

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are widely found in soil and sediment, surface and ground water, as well as our drinking water systems. PFASs, especially the ones originated from aqueous film-forming foams (AFFFs), are a significant and constant threat to groundwater quality. Since only a few PFASs among several thousand used in commerce are regulated in Canada, environmental and public health protection agencies are urgently gathering the data required to address the safety and regulatory questions related to many PFASs. Impacted communities worldwide are searching for effective solutions to remediate polluted soil and water systems. Despite multiple C-F bonds in their structure, most of the polyfluoroalkyl chemicals can undergo biotransformation and even defluorinate. Transformation products are found to be complex; some are persistent while others are highly toxic. The failure to identify and monitor many transformation products could lead to a great uncertainty on the environmental impact of PFASs. Therefore, to develop effective strategies for management and remediation of thousands of PFAS contaminated sites, improved understanding of transformation pathways present in microbial systems is warranted. The identity, diversity, and richness of microorganisms, as well as functional genes that are responsible for such transformations, must be explored. ******The overall goal of the research is to elucidate novel processes and mechanisms by which microorganisms break down C-F in polyfluoroalkyl chemicals, and to discover the diversity and identity of such microorganisms. One major focus of the work in my groups is to establish new biotransformation rules through experimental work using model PFASs and to develop prediction capability that can be applied to elucidating the environmental fate of several hundred PFASs detected in the environment. In the meantime, we will use mixed and pure bacterial culture to investigate the mechanisms and limitations of “one-carbon removal pathways”, which microorganisms employ to defluorinate PFASs. We will also be working towards identifying the microbes involved in degrading polyfluoroalkyl chemicals in the environment through a culture-independent technique of stable-isotope probing. The interdisciplinary research linking environmental chemistry with microbiology is necessary for generating the insight into the interactions of PFASs with microorganisms or enzymes. The proposed research program will prioritize the training of HQP using an integrated multidisciplinary approach and a collaborative training environment. At least 1 postdoctoral fellow, 2 Ph.D., 2 Master's and 5 undergraduates will be receiving training through this program and obtain the skills and visions that are needed for the Canadian workforce in emerging areas of engineering and applied science.*****