THE BIOTRANSFORMATION OF DECANES WITH POLY- OR PERFLUORINATED CARBONS AND THE DESTRUCTION OF PER- AND POLYFLUOROALKYL SUBSTANCES IN ALKALINE CONDITIONS

Author

Alexander Stephan Walls, University of Tennessee, KnoxvilleFollow

Date of Award

8-2025

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Chemistry

Major Professor

Shawn R. Campagna

Committee Members

Shawn R. Campagna, Frank E. Löffler, Michael D. Best, Fred Heberle

Abstract

During growth with terminally monofluorinated decanes, the soil isolate Pseudomonas sp. strain 273 releases inorganic fluoride and channels metabolites into the phospholipid pool resulting in the formation of fluoromembranes. We explore the ability of this bacterium to metabolize terminally mono-, di-, tri-, and pentafluorinated decanes. Strain 273 grew with 7 mM (nominal) 1-fluorodecane (1-FD), 1,10-difluorodecane (1,10-DFD), 1,1-difluorodecane (1,1-DFD), 1,1,1-trifluorodecane (TFD), and 1,1,1,2,2-pentafluorodecane (PFD) under oxic conditions. Fluorine-nuclear magnetic resonance (¹⁹F NMR) [proton number] detected inorganic fluoride release (1-FD, 1,10-DFD, 1,1-DFD, and PFD-grown cultures) and terminally mono-, di-, tri-, and pentafluorinated metabolites (1-FD, 1,10-DFD, 1,1-DFD, TFD, and PFD-grown cultures). Global lipidomic profiling supported our hypothesis of the biosynthesis of mono-, di-, tri-, tetra-, penta- and decafluorinated glycerophospholipids during growth, highlighting the ability of this bacterium to incorporate organofluorines into glycerophospholipid in the presence of fluorinated decanes. Data from ¹⁹F NMR [proton number] combined with ultra-high-performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) suggests organofluorines to be at the terminal position of glycerophospholipid (GP) sn1/-sn2 acyl chains using a reversed phase method. Gas chromatography-MS (GC-MS) analysis identified terminally polyfluorinated short chain fatty acids as major catabolites during growth with the polyfluorinated decanes. These findings advance our understanding of microbial degradation of and dehalogenation of terminally poly- and perfluorinated decanes and highlight the formation of fluoromembranes as a sink for organofluorine. An additional study also demonstrated the destruction of per- and polyfluoroalkyl substances (PFASs) under hydrothermal alkaline reaction conditions using lower temperatures and pressures as a promising chemical approach for PFASs destruction.

Recommended Citation

Walls, Alexander Stephan, "THE BIOTRANSFORMATION OF DECANES WITH POLY- OR PERFLUORINATED CARBONS AND THE DESTRUCTION OF PER- AND POLYFLUOROALKYL SUBSTANCES IN ALKALINE CONDITIONS. " PhD diss., University of Tennessee, 2025.
https://trace.tennessee.edu/utk_graddiss/12667