Resilience of Dehalococcoides enables complete reductive dechlorination of trichloroethene to ethene under high PFOS stress

Abstract

Perfluorooctane sulfonate (PFOS) is a dominant per- and polyfluoroalkyl substance (PFAS) at aqueous film-forming foam-impacted sites, yet its specific inhibitory effect on reductive dechlorination of trichloroethene (TCE) remains poorly understood. We investigated TCE dechlorination in a Dehalococcoides (Dhc) and Dehalogenimonas (Dhg)-containing consortium under PFOS stress (20–100 mg/L). While the initial TCE dechlorination rates decreased with increasing PFOS concentrations, the final step of vinyl chloride dechlorination to ethene remained largely unaffected. Microbial community analysis revealed that Dhc and Acetobacterium exhibited greater resilience to 100 mg/L PFOS than Dhg and Clostridium_sensu_stricto_7, with alpha diversity significantly reduced at 100 mg/L PFOS. PFOS, but not perfluorooctanoic acid, was identified as the primary inhibitor of TCE dechlorination. Metagenomic sequencing identified two PFOS-tolerant Dhc strains (THU3 and THU4) that harbored specific reductive dehalogenase genes (vcrA and tceA). Our findings demonstrate the functional resilience of Dhc and its potential as a key agent for bioremediation at PFAS-co-contaminated sites.

Graphical abstract

Keywords

PFOS inhibition / Reductive dechlorination / Dehalococcoides / Resilience

Highlight

	● Complete TCE dechlorination to ethene was sustained with high PFOS stress.
	● Dehalococcoides exhibited greater resilience to PFOS than Dehalogenimonas .• PFOS, but not PFOA, was identified as the primary inhibitor of TCE dechlorination.
	● The vinyl chloride to ethene step remained robust under high PFOS exposure.
	● Two PFOS-tolerant Dhc strains harbored unique reductive dehalogenase genes.

References

[1] Adamson D T , Kulkarni P R , Nickerson A , Higgins C P , Field J , Schwichtenberg T , Newell C , Kornuc J J . (2022). Characterization of relevant site-specific PFAS fate and transport processes at multiple AFFF sites. Environmental Advances, 7: 100167

[2] Amos B K , Ritalahti K M , Cruz-Garcia C , Padilla-Crespo E , Löffler F E . (2008). Oxygen effect on Dehalococcoides viability and biomarker quantification. Environmental Science & Technology, 42(15): 5718–5726

[3] Bankevich A , Nurk S , Antipov D , Gurevich A A , Dvorkin M , Kulikov A S , Lesin V M , Nikolenko S I , Pham S , Prjibelski A D . et al. (2012). SPAdes: a new genome assembly algorithm and its applications to single-cell sequencing. Journal of Computational Biology, 19(5): 455–477

[4] Bowman K S , Rainey F A , Moe W M . (2009). Production of hydrogen by Clostridium species in the presence of chlorinated solvents. FEMS Microbiology Letters, 290(2): 188–194

[5] Brusseau M L , Anderson R H , Guo B . (2020). PFAS concentrations in soils: background levels versus contaminated sites. Science of the Total Environment, 740: 140017

[6] Buchfink B , Xie C , Huson D H . (2015). Fast and sensitive protein alignment using DIAMOND. Nature Methods, 12(1): 59–60

[7] Cai Y P , Chen H L , Yuan R F , Wang F , Chen Z B , Zhou B H . (2019). Toxicity of perfluorinated compounds to soil microbial activity: effect of carbon chain length, functional group and soil properties. Science of the Total Environment, 690: 1162–1169

[8] Callahan B J , McMurdie P J , Rosen M J , Han A W , Johnson A J A , Holmes S P . (2016). DADA2: high-resolution sample inference from Illumina amplicon data. Nature Methods, 13(7): 581–583

[9] Cao L F , Xu W X , Wan Z R , Li G H , Zhang F . (2022). Occurrence of PFASs and its effect on soil bacteria at a fire-training area using PFOS-restricted aqueous film-forming foams. iScience, 25(4): 104084

[10] Chen D , Hu X H , Chen C H , Gao Y M , Zhou Q H , Feng X , Xu X H , Lin D H , Xu J . (2024). Impacts of perfluoroalkyl substances on aqueous and nonaqueous phase liquid dechlorination by sulfidized nanoscale zerovalent iron. Environmental Science & Technology, 58(25): 11193–11202

[11] Chen G , Murdoch F K , Xie Y C , Murdoch R W , Cui Y R , Yang Y , Yan J , Key T A , Löffler F E . (2022). Dehalogenation of chlorinated ethenes to ethene by a novel isolate, “Candidatus Dehalogenimonas etheniformans”. Applied and Environmental Microbiology, 88(12): e00443–22

[12] Cook E K , Olivares C I , Antell E H , Tsou K , Kim T-K , Cuthbertson A , Higgins C P , Sedlak D L , Alvarez-Cohen L . (2024). Sulfonamide per- and polyfluoroalkyl substances can impact microorganisms used in aromatic hydrocarbon and trichloroethene bioremediation. Environmental Science & Technology, 58(20): 8792–8802

[13] Cui Y RLi X YYan JLv YJin H JWang J JChen GKara-Murdoch FYang YLöffler F E (2023). Dehalogenimonas etheniformans sp. nov., a formate-oxidizing, organohalide-respiring bacterium isolated from grape pomace. International Journal of Systematic and Evolutionary Microbiology, 73(5): 5881

[14] Ding C , Rogers M J , He J Z . (2020). Dehalococcoides mccartyi strain GEO12 has a natural tolerance to chloroform inhibition. Environmental Science & Technology, 54(14): 8750–8759

[15] Fang J H , Li S L , Qiu R L , Zhang W X . (2024). “Forever chemicals”: a sticky environmental problem. Frontiers of Environmental Science & Engineering, 18(10): 131

[16] Fitzgerald N J M , Temme H R , Simcik M F , Novak P J . (2019). Aqueous film forming foam and associated perfluoroalkyl substances inhibit methane production and Co-contaminant degradation in an anaerobic microbial community. Environmental Science: Processes & Impacts, 21(11): 1915–1925

[17] Fletcher K E , Costanza J , Cruz-Garcia C , Ramaswamy N S , Pennell K D , Löffler F E . (2011). Effects of elevated temperature on Dehalococcoides dechlorination performance and DNA and RNA biomarker abundance. Environmental Science & Technology, 45(2): 712–718

[18] Grostern A , Edwards E A . (2006). Growth of Dehalobacter and Dehalococcoides spp. during degradation of chlorinated ethanes. Applied and Environmental Microbiology, 72(1): 428–436

[19] He J Z , Holmes V F , Lee P K H , Alvarez-Cohen L . (2007). Influence of vitamin B₁₂ and cocultures on the growth of Dehalococcoides isolates in defined medium. Applied and Environmental Microbiology, 73(9): 2847–2853

[20] He J Z , Ritalahti K M , Yang K L , Koenigsberg S S , Löffler F E . (2003). Detoxification of vinyl chloride to ethene coupled to growth of an anaerobic bacterium. Nature, 424(6944): 62–65

[21] Hnatko J P , Liu C , Elsey J L , Dong S , Fortner J D , Pennell K D , Abriola L M , Cápiro N L . (2023). Microbial reductive dechlorination by a commercially available dechlorinating consortium is not inhibited by perfluoroalkyl acids (PFAAs) at field-relevant concentrations. Environmental Science & Technology, 57(22): 8301–8312

[22] Hua Z S , Han Y J , Chen L X , Liu J , Hu M , Li S J , Kuang J L , Chain P S G , Huang L N , Shu W S . (2015). Ecological roles of dominant and rare prokaryotes in acid mine drainage revealed by metagenomics and metatranscriptomics. The ISME Journal, 9(6): 1280–1294

[23] Jin H J , Li X Y , Wang H Y , Cápiro N L , Li X C , Löffler F E , Yan J , Yang Y . (2022). Anaerobic biohydrogenation of isoprene by Acetobacterium wieringae strain Y. mBio, 13(6): e02086–22

[24] Kang D D , Froula J , Egan R , Wang Z . (2015). MetaBAT, an efficient tool for accurately reconstructing single genomes from complex microbial communities. PeerJ, 3: e1165

[25] Lee P K H , Cheng D , West K A , Alvarez-Cohen L , He J Z . (2013). Isolation of two new Dehalococcoides mccartyi strains with dissimilar dechlorination functions and their characterization by comparative genomics via microarray analysis. Environmental Microbiology, 15(8): 2293–2305

[26] Liu N , Li H J , Li M Y , Ding L Z , Weng C H , Dong C D . (2017). Oxygen exposure effects on the dechlorinating activities of a trichloroethene-dechlorination microbial consortium. Bioresource Technology, 240: 98–105

[27] Löffler F ERitalahti K MZinder S H (2013). Dehalococcoides and reductive dechlorination of chlorinated solvents. In: Stroo H F, Leeson A, Ward C H, eds. Bioaugmentation for Groundwater Remediation. New York: Springer, 39–88

[28] Marcet T F , Cápiro N L , Yang Y , Löffler F E , Pennell K D . (2018). Impacts of low-temperature thermal treatment on microbial detoxification of tetrachloroethene under continuous flow conditions. Water Research, 145: 21–29

[29] Mayer-Blackwell K , Fincker M , Molenda O , Callahan B , Sewell H , Holmes S , Edwards E A , Spormann A M . (2016). 1, 2-Dichloroethane exposure alters the population structure, metabolism, and kinetics of a trichloroethene-dechlorinating Dehalococcoides mccartyi consortium. Environmental Science & Technology, 50(22): 12187–12196

[30] McGuire M E , Schaefer C , Richards T , Backe W J , Field J A , Houtz E , Sedlak D L , Guelfo J L , Wunsch A , Higgins C P . (2014). Evidence of remediation-induced alteration of subsurface poly- and perfluoroalkyl substance distribution at a former firefighter training area. Environmental Science & Technology, 48(12): 6644–6652

[31] McKenzie E R , Siegrist R L , McCray J E , Higgins C P . (2016). The influence of a non-aqueous phase liquid (NAPL) and chemical oxidant application on perfluoroalkyl acid (PFAA) fate and transport. Water Research, 92: 199–207

[32] Quast C , Pruesse E , Yilmaz P , Gerken J , Schweer T , Yarza P , Peplies J , Glöckner F O . (2013). The SILVA ribosomal RNA gene database project: improved data processing and web-based tools. Nucleic Acids Research, 41(D1): D590–D596

[33] Schloss P D , Westcott S L , Ryabin T , Hall J R , Hartmann M , Hollister E B , Lesniewski R A , Oakley B B , Parks D H , Robinson C J . et al. (2009). Introducing mothur: open-source, platform-independent, community-supported software for describing and comparing microbial communities. Applied and Environmental Microbiology, 75(23): 7537–7541

[34] Senevirathna S T M L D , Krishna K C B , Mahinroosta R , Sathasivan A . (2022). Comparative characterization of microbial communities that inhabit PFAS-rich contaminated sites: a case-control study. Journal of Hazardous Materials, 423: 126941

[35] Stroo H FWest M RKueper B HBorden R CMajor D WWard C H (2014). In situ bioremediation of chlorinated ethene source zones. In: Kueper B H, Stroo H F, Vogel C M, Ward C H, eds. Chlorinated Solvent Source Zone Remediation. New York: Springer, 395–457

[36] Tang Z W , Song X , Xu M M , Yao J , Ali M , Wang Q , Zeng J , Ding X Y , Wang C J , Zhang Z X . et al. (2022). Effects of co-occurrence of PFASs and chlorinated aliphatic hydrocarbons on microbial communities in groundwater: a field study. Journal of Hazardous Materials, 435: 128969

[37] Weathers T S , Harding-Marjanovic K , Higgins C P , Alvarez-Cohen L , Sharp J O . (2016). Perfluoroalkyl acids inhibit reductive dechlorination of trichloroethene by repressing Dehalococcoides. Environmental Science & Technology, 50(1): 240–248

[38] Weathers T S , Higgins C P , Sharp J O . (2015). Enhanced biofilm production by a toluene-degrading Rhodococcus observed after exposure to perfluoroalkyl acids. Environmental Science & Technology, 49(9): 5458–5466

[39] Wen L L , Chen J X , Fang J Y , Li A , Zhao H P . (2017). Effects of 1, 1, 1-trichloroethane and triclocarban on reductive dechlorination of trichloroethene in a TCE-reducing culture. Frontiers in Microbiology, 8: 1439

[40] Wu E H , Wang K , Liu Z Z , Wang J , Yan H C , Zhu X Y , Zhu X M , Chen B L . (2023). Metabolic and microbial profiling of soil microbial community under per- and polyfluoroalkyl substance (PFAS) stress. Environmental Science & Technology, 57(51): 21855–21865

[41] Wu E H , Wang K , Zhou J Q , Wang J , Liu Z Z , Yan H C , Zhu X Y , Chen B L . (2025). Fatty acid metabolic impairment in soil microbes induced by PFAS: dependence on the fluorocarbon chain length, headgroups, and ether attached. Environmental Science & Technology, 59(11): 5452–5462

[42] Wu R F , Wang S Q . (2022). Integration of microbial reductive dehalogenation with persulfate activation and oxidation (Bio-RD-PAO) for complete attenuation of organohalides. Frontiers of Environmental Science & Engineering, 16(2): 22

[43] Xu G F , Zhao S Y , Chen C , Zhang N , He J Z . (2023). Alleviating chlorinated alkane inhibition on Dehalococcoides to achieve detoxification of chlorinated aliphatic cocontaminants. Environmental Science & Technology, 57(40): 15112–15122

[44] Yan J , Wang J J , Villalobos Solis M I , Jin H J , Chourey K , Li X Y , Yang Y , Yin Y C , Hettich R L , Löffler F E . (2021). Respiratory vinyl chloride reductive dechlorination to ethene in TceA-expressing Dehalococcoides mccartyi. Environmental Science & Technology, 55(8): 4831–4841

[45] Yang Y , Cápiro N L , Yan J , Marcet T F , Pennell K D , Löffler F E . (2017a). Resilience and recovery of Dehalococcoides mccartyi following low pH exposure. FEMS Microbiology Ecology, 93(12): fix130

[46] Yang Y , Higgins S A , Yan J , Şimşir B , Chourey K , Iyer R , Hettich R L , Baldwin B , Ogles D M , Löffler F E . (2017b). Grape pomace compost harbors organohalide-respiring Dehalogenimonas species with novel reductive dehalogenase genes. The ISME Journal, 11(12): 2767–2780

[47] Yang Y , Jin H J , Li X Y , Yan J . (2023). Biohydrogenation of 1, 3-butadiene to 1-butene under acetogenic conditions by Acetobacterium wieringae. Environmental Science & Technology, 57(4): 1637–1645

[48] Zhang F , Ge R L , Wan Z R , Li G H , Cao L F . (2023). Dual effects of PFOA or PFOS on reductive dechlorination of trichloroethylene (TCE). Water Research, 240: 120093

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