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Yu Y, Xu F, Zhao W, Thoma C, Che S, Richman JE, Jin B, Zhu Y, Xing Y, Wackett L, Men Y. Electron bifurcation and fluoride efflux systems implicated in defluorination of perfluorinated unsaturated carboxylic acids by Acetobacterium spp. SCIENCE ADVANCES 2024; 10:eado2957. [PMID: 39018407 PMCID: PMC466959 DOI: 10.1126/sciadv.ado2957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 06/12/2024] [Indexed: 07/19/2024]
Abstract
Enzymatic cleavage of C─F bonds in per- and polyfluoroalkyl substances (PFAS) is largely unknown but avidly sought to promote systems biology for PFAS bioremediation. Here, we report the reductive defluorination of α, β-unsaturated per- and polyfluorocarboxylic acids by Acetobacterium spp. The microbial defluorination products were structurally confirmed and showed regiospecificity and stereospecificity, consistent with their formation by enzymatic reactions. A comparison of defluorination activities among several Acetobacterium species indicated that a functional fluoride exporter was required for the detoxification of the released fluoride. Results from both in vivo inhibition tests and in silico enzyme modeling suggested the involvement of enzymes of the flavin-based electron-bifurcating caffeate reduction pathway [caffeoyl-CoA reductase (CarABCDE)] in the reductive defluorination. This is a report on specific microorganisms carrying out enzymatic reductive defluorination of PFAS, which could be linked to electron-bifurcating reductases that are environmentally widespread.
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Affiliation(s)
- Yaochun Yu
- Department of Chemical and Environmental Engineering, University of California, Riverside, Riverside, CA 92521, USA
| | - Fengjun Xu
- Department of Chemical and Environmental Engineering, University of California, Riverside, Riverside, CA 92521, USA
| | - Weiyang Zhao
- Department of Chemical and Environmental Engineering, University of California, Riverside, Riverside, CA 92521, USA
| | - Calvin Thoma
- Department of Biochemistry, Molecular Biology and Biophysics and Biotechnology Institute, University of Minnesota, Twin Cities, MN 55108, USA
| | - Shun Che
- Department of Chemical and Environmental Engineering, University of California, Riverside, Riverside, CA 92521, USA
| | - Jack E. Richman
- Department of Biochemistry, Molecular Biology and Biophysics and Biotechnology Institute, University of Minnesota, Twin Cities, MN 55108, USA
| | - Bosen Jin
- Department of Chemical and Environmental Engineering, University of California, Riverside, Riverside, CA 92521, USA
| | - Yiwen Zhu
- Department of Chemical and Environmental Engineering, University of California, Riverside, Riverside, CA 92521, USA
| | - Yue Xing
- Department of Chemical and Environmental Engineering, University of California, Riverside, Riverside, CA 92521, USA
| | - Lawrence Wackett
- Department of Biochemistry, Molecular Biology and Biophysics and Biotechnology Institute, University of Minnesota, Twin Cities, MN 55108, USA
| | - Yujie Men
- Department of Chemical and Environmental Engineering, University of California, Riverside, Riverside, CA 92521, USA
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Yu Y, Xu F, Zhao W, Thoma C, Che S, Richman JE, Jin B, Zhu Y, Xing Y, Wackett L, Men Y. Electron-bifurcation and fluoride efflux systems in Acetobacterium spp. drive defluorination of perfluorinated unsaturated carboxylic acids. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.13.568471. [PMID: 38168399 PMCID: PMC10760045 DOI: 10.1101/2023.12.13.568471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Enzymatic cleavage of C-F bonds in per- and polyfluoroalkyl substances (PFAS) is largely unknown but avidly sought to promote systems biology for PFAS bioremediation. Here, we report the reductive defluorination of α, β-unsaturated per- and polyfluorocarboxylic acids by Acetobacterium spp. Two critical molecular features in Acetobacterium species enabling reductive defluorination are (i) a functional fluoride efflux transporter (CrcB) and (ii) an electron-bifurcating caffeate reduction pathway (CarABCDE). The fluoride transporter was required for detoxification of released fluoride. Car enzymes were implicated in defluorination by the following evidence: (i) only Acetobacterium spp. with car genes catalyzed defluorination; (ii) caffeate and PFAS competed in vivo ; (iii) models from the X-ray structure of the electron-bifurcating reductase (CarC) positioned the PFAS substrate optimally for reductive defluorination; (iv) products identified by 19 F-NMR and high-resolution mass spectrometry were consistent with the model. Defluorination biomarkers identified here were found in wastewater treatment plant metagenomes on six continents.
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Jaffé PR, Huang S. Rebuttal to Correspondence on "Defluorination of Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS) by Acidimicrobium sp. Strain A6". ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:20443-20447. [PMID: 37913821 DOI: 10.1021/acs.est.3c07853] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
Affiliation(s)
- Peter R Jaffé
- Department of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Shan Huang
- Department of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey 08544, United States
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