Efficient degradation of various emerging pollutants by wild type and evolved fungal DyP4 peroxidases

PLoS One. 2022 Jan 13;17(1):e0262492. doi: 10.1371/journal.pone.0262492. eCollection 2022.

Abstract

The accumulation of emerging pollutants in the environment remains a major concern as evidenced by the increasing number of reports citing their potential risk on environment and health. Hence, removal strategies of such pollutants remain an active area of investigation. One way through which emerging pollutants can be eliminated from the environment is by enzyme-mediated bioremediation. Enzyme-based degradation can be further enhanced via advanced protein engineering approaches. In the present study a sensitive and robust bioanalytical liquid chromatography-tandem mass spectrometry (LCMSMS)-based approach was used to investigate the ability of a fungal dye decolorizing peroxidase 4 (DyP4) and two of its evolved variants-that were previously shown to be H2O2 tolerant-to degrade a panel of 15 different emerging pollutants. Additionally, the role of a redox mediator was examined in these enzymatic degradation reactions. Our results show that three emerging pollutants (2-mercaptobenzothiazole (MBT), paracetamol, and furosemide) were efficiently degraded by DyP4. Addition of the redox mediator had a synergistic effect as it enabled complete degradation of three more emerging pollutants (methyl paraben, sulfamethoxazole and salicylic acid) and dramatically reduced the time needed for the complete degradation of MBT, paracetamol, and furosemide. Further investigation was carried out using pure MBT to study its degradation by DyP4. Five potential transformation products were generated during the enzymatic degradation of MBT, which were previously reported to be produced during different bioremediation approaches. The current study provides the first instance of the application of fungal DyP4 peroxidases in bioremediation of emerging pollutants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biodegradation, Environmental
  • Chromatography, Liquid / methods
  • Environmental Pollutants
  • Environmental Restoration and Remediation / methods*
  • Fungal Proteins / metabolism
  • Fungi / metabolism
  • Hydrogen Peroxide
  • Oxidation-Reduction
  • Peroxidases / metabolism*
  • Peroxidases / physiology
  • Pleurotus / enzymology*
  • Pleurotus / metabolism
  • Tandem Mass Spectrometry / methods
  • Water Pollutants, Chemical / chemistry

Substances

  • Environmental Pollutants
  • Fungal Proteins
  • Water Pollutants, Chemical
  • Hydrogen Peroxide
  • Peroxidases

Grants and funding

Generous support (CIRA-2020-046 and FSU-2019-09) to SSA from Khalifa University is graciously acknowledged. We also thank EPSRC (EP/E036252/1), the Open Project Funding of the State Key Laboratory of Bioreactor Engineering (to TSW), the Royal Academy of Engineering (the Leverhulme Trust Senior Research Fellowship; to TSW; LTSRF1819\15\21) and the NSTDA Visiting Professorship (to TSW) for financial support. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.