16S rRNA gene data for aerobic BTEX-degrading enrichments exposed to sulfonamide polyfluorinated substances in fire-fighting foams and transformation products

Per- and polyfluoroalkyl substances (PFASs) from aqueous film forming foams (AFFFs) can hinder bioremediation of co-contaminants, such as trichloroethene (TCE) and benzene, toluene, ethylbenzene, and xylene (BTEX). Anaerobic dechlorination can require bioaugmentation of Dehalococcoides and for BTEX, oxygen is often sparged to stimulate in-situ aerobic biodegradation. We tested PFAS inhibition to TCE and BTEX bioremediation by exposing an anaerobic TCE-dechlorinating co-culture, an aerobic BTEX-degrading enrichment culture, and an anaerobic toluene-degrading enrichment culture to n-dimethyl perfluorohexane sulfonamido amine (AmPr-FHxSA), perfluorohexane sulfonamide (FHxSA), perfluorohexane sulfonic acid (PFHxS), or non-fluorinated surfactant sodium dodecyl sulfate (SDS). The anaerobic TCE-dechlorinating co-culture was resistant to individual PFASs exposures but was inhibited by >1,000x diluted AFFF. FHxSA and AmPr-FHxSA inhibited the aerobic BTEX-degrading enrichment. The anaerobic toluene-degrading enrichment was not inhibited by AFFF or individual PFASs. Increases in amino acids in the anaerobic TCE-dechlorinating co-culture compared to the control indicated stress response, while the BTEX culture exhibited lower concentrations of all amino acids upon exposure to most surfactants (both fluorinated and non-fluorinated) compared to the control. These data suggest the main mechanisms of microbial toxicity are related to interactions with cell membrane synthesis as well as protein stress signaling.

Methods
At the end of the BTEX enrichment experiments with 10 μM of each PFAS, 4 mL slurry samples were centrifuged at 10,000g for 10 minutes, decanted, and extracted for DNA using a DNeasy PowerSoil Kit (Qiagen, Hilden, Germany) according to the manufacturer’s instructions. Extracted DNA was stored at -80°C and sent to Novogene Corporation Inc. (Sacramento, CA, USA) for bacterial 16S rRNA amplification and sequencing. At Novogene Corporation Inc. (Sacramento, CA, USA), DNA concentrations were normalized to 10 ng/μL and amplified targeting the V3-V4 region (470bp fragment length).  At Novogene Corporation Inc. (Sacramento, CA, USA), DNA concentrations were normalized to 297 10 ng/μL and amplified targeting the V3-V4 region (470bp fragment length). The amplicons 298 were then assessed for quality on an Agilent 5400 Fragment Analyzer (Agilent, Palo Alto, CA, 299 USA) before library preparation and sequencing on an Illumina NovaSeq6000 PE250 platform 300 (Illumina, San Diego, CA, USA).