Fitzgerald Nicole J M, Wargenau Andreas, Sorenson Carlise, Pedersen Joel, Tufenkji Nathalie, Novak Paige J, Simcik Matt F
Department of Civil, Environmental, and Geo-Engineering , University of Minnesota , 500 Pillsbury Drive SE , Minneapolis , Minnesota 55455 , United States.
Department of Chemical Engineering , McGill University , 3610 University Street , Montreal , Quebec H3A 0C5 , Canada.
Environ Sci Technol. 2018 Sep 18;52(18):10433-10440. doi: 10.1021/acs.est.8b02912. Epub 2018 Sep 10.
Perfluoroalkyl substances (PFAS) are ubiquitous and persistent environmental contaminants, yet knowledge of their biological effects and mechanisms of action is limited. The highest aqueous PFAS concentrations are found in areas where bacteria are relied upon for functions such as nutrient cycling and contaminant degradation, including fire-training areas, wastewater treatment plants, and landfill leachates. This research sought to elucidate one of the mechanisms of action of PFAS by studying their uptake by bacteria and partitioning into model phospholipid bilayer membranes. PFAS partitioned into bacteria as well as model membranes (phospholipid liposomes and bilayers). The extent of incorporation into model membranes and bacteria was positively correlated to the number of fluorinated carbons. Furthermore, incorporation was greater for perfluorinated sulfonates than for perfluorinated carboxylates. Changes in zeta potential were observed in liposomes but not bacteria, consistent with PFAS being incorporated into the phospholipid bilayer membrane. Complementary to these results, PFAS were also found to alter the gel-to-fluid phase transition temperature of phospholipid bilayers, demonstrating that PFAS affected lateral phospholipid interactions. This investigation compliments other studies showing that sulfonated PFAS and PFAS with more than seven fluorinated carbons have a higher potential to accumulate within biota than carboxylated and shorter-chain PFAS.
全氟烷基物质（PFAS）是普遍存在且持久的环境污染物，然而，我们对其生物学效应和作用机制的了解有限。在依赖细菌进行养分循环和污染物降解等功能的区域，如消防训练区、污水处理厂和垃圾渗滤液中，发现了水中PFAS的最高浓度。本研究旨在通过研究PFAS被细菌摄取并分配到模型磷脂双分子层膜中的情况，阐明PFAS的一种作用机制。PFAS既分配到细菌中，也分配到模型膜（磷脂脂质体和双分子层）中。掺入模型膜和细菌中的程度与氟化碳的数量呈正相关。此外，全氟磺酸盐的掺入量高于全氟羧酸盐。在脂质体中观察到了ζ电位的变化，但在细菌中未观察到，这与PFAS被掺入磷脂双分子层膜一致。与这些结果相辅相成的是，还发现PFAS会改变磷脂双分子层的凝胶-流体相变温度，表明PFAS影响了磷脂的侧向相互作用。这项研究补充了其他研究结果，即磺化PFAS和含七个以上氟化碳的PFAS比羧化和短链PFAS在生物群中积累的潜力更高。
