Assessing aerobic biotransformation of 8:2 fluorotelomer alcohol in aqueous film-forming foam (AFFF)-impacted soils: Pathways and microbial community dynamics

Using Network Analysis and Predictive Functional Analysis to Explore the Fluorotelomer Biotransformation Potential of Soil Microbial Communities

“…71 Genus Variovorax was identified as a potential degrader in a previous study on 8:2 FTOH biotransformation under aerobic conditions. 21 Similar to the degree (number of connections with other nodes) of soil generalists identified in soil samples collected across a spatial or temporal gradient (<20), 31 the generalists identified in this study also have small degrees (1, 2, and 13). Despite having relatively low degrees, these generalist taxa are believed to possess strong adaptability to different conditions considering that two geographically and physicochemically distinct soil sources are involved, indicating the potential significance of these generalists in fluorotelomer biotransformation.…”

“…107,108 These dehydrogenases likely play a role in the initial steps of FTOH biotransformation, oxidizing n:2 FTOH into corresponding fluorotelomer aldehydes and carboxylic acids (n:2 FTAL, FTCA, and FTUA). 21,109 Although these steps were previously associated with anaerobic degradation of benzoate, 107 they were also found in aerobic and anaerobic 8:2 FTOH biotransformation and aerobic 6:2 FTS biotransformation. 21−23 This supports the presence of dehydrogenase genes or genes with similar functions during fluorotelomer biotransformation under both oxic and anoxic conditions.…”

“…Raw 16S rRNA gene sequencing data were obtained from seven sets of microcosm experiments, − investigating 8:2 FTOH and 6:2 FTS biotransformation. Five sets of microcosm experiments examined 8:2 FTOH biotransformation: One was conducted using soil collected from Robins Air Force Base (AFB) (hereafter termed Robins AFB soil) under aerobic conditions, and four used soils from the former Loring AFB (hereafter termed Loring AFB soil) under aerobic conditions, as well as nitrate-, sulfate-, and iron-reducing conditions.…”

“…Soils, as natural reservoirs of complex and diverse microbial populations, have the potential to degrade various organic pollutants. Microbial communities derived from soils have been reported to transform PFAS, including fluorotelomer alcohols − and nitrogen-containing polyfluoroalkyl substances. − Although microorganisms play important roles in PFAS biotransformation, the crucial microorganisms and functional genes responsible for the biotransformation processes remain largely undetermined.…”

“…Previously, a series of microcosm experiments was conducted to investigate biotransformation kinetics and pathways of two fluorotelomers, 8:2 fluorotelomer alcohol (8:2 FTOH) and 6:2 FTS in aqueous film forming foam (AFFF)-impacted soils, as well as the impact of fluorotelomers on the microbial communities. − To gain more insight into the potential biotransformation of fluorotelomers by soil microorganisms, this study utilized the 16S rRNA gene sequencing data collected from those microcosm experiments in downstream analyses using bioinformatics and computational tools. Specifically, the aims of this study were to (a) reveal co-occurrence patterns of microbes in response to fluorotelomer biotransformation, (b) identify potential key taxa in the soil microbial communities that play a role in fluorotelomer biotransformation, and (c) explore potential functional genes that contribute to fluorotelomer biotransformation and the microbes that could potentially harbor the functional genes.…”