| Autor: |
LaFond JA; Department of Civil, Environmental & Construction Engineering, Texas Tech University, Lubbock, Texas 79409, United States., Rezes R; Biotechnology Development & Applications Group, APTIM, Lawrenceville, New Jersey 08648, United States., Shojaei M; Department of Civil & Environmental Engineering, Duke University, Durham, North Carolina 27710, United States., Anderson T; The Institute of Environmental and Human Health, Texas Tech University, Lubbock, Texas 79409, United States., Jackson WA; Department of Civil, Environmental & Construction Engineering, Texas Tech University, Lubbock, Texas 79409, United States., Guelfo JL; Department of Civil, Environmental & Construction Engineering, Texas Tech University, Lubbock, Texas 79409, United States., Hatzinger PB; Biotechnology Development & Applications Group, APTIM, Lawrenceville, New Jersey 08648, United States. |
| Abstrakt: |
Numerous US drinking water aquifers have been contaminated with per- and polyfluoroalkyl substances (PFAS) from fire-fighting and fire-training activities using aqueous film-forming foam (AFFF). These sites often contain other organic compounds, such as fuel hydrocarbons and methane, which may serve as primary substrates for cometabolic (i.e., nongrowth-linked) biotransformation reactions. This work investigates the abilities of AFFF site relevant bacteria (methanotrophs, propanotrophs, octane, pentane, isobutane, toluene, and ammonia oxidizers), known to express oxygenase enzymes when degrading their primary substrates, to biotransform perfluoroalkyl acid (PFAA) precursors to terminal PFAAs. Microcosms containing AFFF-impacted groundwater, 6:2 fluorotelomer sulfonate (6:2 FTS), or N -ethylperfluorooctane sulfonamidoethanol (EtFOSE) were inoculated with the aerobic cultures above and incubated for 4 and 8 weeks at 22 °C. Bottles were sacrificed, extracted, and subjected to target, nontarget, and suspect screening for PFAS. The PFAA precursors 6:2 FTS, N-sulfopropyldimethyl ammoniopropyl perfluorohexane sulfonamide (SPrAmPr-FHxSA), and EtFOSE transformed up to 99, 71, and 93%, respectively, and relevant daughter products, such as the 6:1 fluorotelomer ketone sulfonate (6:1 FTKS), were identified in quantities previously not observed, implicating oxygenase enzymes. This is the first report of a suite of site relevant PFAA precursors being transformed in AFFF-impacted groundwater by bacteria grown on substrates known to induce specific oxygenase enzymes. The data provide crucial insights into the microbial transformation of these compounds in the subsurface. |
