Biodegradation of Polyfluoroalkyl Chemicals in the Environment

全氟烷基和多氟烷基化合物（PFC）广泛用于工业和消费品的表面处理以及作为特种化学品。目前，已经开发了多达数百种不同的应用程序。尽管有几类全氟化学品因其对环境和生态的不利影响而受到严格审查，但其高度的多功能性保证了其在可预见的未来继续使用。 尽管总体上具有高稳定性，但一些多氟烷基化合物由于整体脂肪族官能团而易于环境生物降解。例如，我们已经发现，氟调聚物醇可以经历大量的有氧生物降解和去氧，与传统的智慧相反。新的生物降解机制被发现参与产生新的降解产物以前未知的。这些发现启发我们重新思考高氟化合物的环境反应性以及环境中微生物的代谢能力。在这种情况下，我们建议检查三个有机硫多氟烷基化合物（两个全氟烷基磺酰氨基乙醇和一个氟调聚物磺酸盐），是突出的环境污染物。主要的方法是应用先进的分析技术，通过一系列的实验室实验来阐明感兴趣的化合物的好氧生物降解途径和机制。这项拟议中的研究将解决微生物通过何种机制切割强碳氟键的基本问题。通过研究化学结构对生物降解性和去污潜力的影响，该研究将为设计更好的多氟烷基化学品提供见解，这些化学品不会导致环境中的有害化合物。拟议的研究还通过解决这些化合物如何在自然和工程处理系统中降解以释放潜在的有毒污染物，对当前的国际关注具有重要的适用性。随着对这些关于环境来源和归宿的基本知识的更好理解，未来的环境风险评估和化学品法规可能会更有效地减少PFCs的负面影响。

Perfluoroalkyl and polyfluoroalkyl compounds (PFCs) are widely used in surface treatments for industrial and consumer products and as specialty chemicals. Currently, as many as hundreds of different applications have been developed. Though several categories of PFCs are under strict scrutiny for adverse environmental and ecological impact, the high versatility warrants their continuous use into the foreseeable future. Despite overall high stability, some polyfluoroalkyl compounds are susceptible to environmental biodegradation due to the integral aliphatic functionalities. For example, we have discovered that fluorotelomer alcohols can undergo substantial aerobic biodegradation and defluorination, contrary to conventional wisdom. Novel biodegradation mechanisms were discovered to be involved in generating new degradation products previously unknown. These findings have inspired us to re-think the environmental reactivity of highly fluorinated compounds as well as the metabolic capacities of microorganisms in the environment. In this context, we propose to examine three organosulfur polyfluoroalkyl compounds (two perfluoroalkyl sulfonamidoethanols and one fluorotelomer sulfonate) that are prominent environmental contaminants. The major approach is to apply advanced analytical techniques to elucidate aerobic biodegradation pathways and mechanisms of compounds of interest through a series of laboratory experiments. The proposed research will address the fundamental question of by what mechanisms microorganisms can cleave strong carbon-fluorine bonds. By examining the influence of chemical structure on biodegradability and defluorination potential, the research will be providing insights for designing better polyfluoroalkyl chemicals that do not lead to harmful compounds in the environment. The proposed research also has significant applicability to current international concerns by addressing how these compounds are degraded in natural and engineered treatment systems to release potentially toxic pollutants. With better understanding of such fundamental knowledge on environmental sources and fate, future environmental risk assessment and chemical regulations may be more effective in minimizing negative impact of PFCs.