Ecotoxicology and Environmental Safety (Jan 2024)

Genome sequencing of Porostereum spadiceum to study the degradation of levofloxacin

  • Amal Ben Ayed,
  • Imen Akrout,
  • Karima Staita,
  • Quentin Albert,
  • Stéphane Greff,
  • Charlotte Simmler,
  • Steven Ahrendt,
  • Kurt LaButti,
  • Anna Lipzen,
  • Guifen He,
  • Emily Savage,
  • Jean Armengaud,
  • Mélodie Kielbasa,
  • David Navarro,
  • Elodie Drula,
  • Annick Turbé-Doan,
  • Emmanuel Bertrand,
  • Anne Lomascolo,
  • Delphine Chaduli,
  • Craig B. Faulds,
  • Mohamed Chamkha,
  • Amina Maalej,
  • Kerrie Barry,
  • Igor V. Grigoriev,
  • Francis Martin,
  • Héla Zouari-Mechichi,
  • Giuliano Sciara,
  • Tahar Mechichi,
  • Eric Record

Journal volume & issue
Vol. 270
p. 115808

Abstract

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Despite various plans to rationalize antibiotic use, antibiotic resistance in environmental bacteria is increasing due to the accumulation of antibiotic residues in the environment. This study aimed to test the ability of basidiomycete fungal strains to biotransform the antibiotic levofloxacin, a widely-used third-generation broad-spectrum fluoroquinolone, and to propose enzyme targets potentially involved in this biotransformation. The biotransformation process was performed using fungal strains. Levofloxacin biotransformation reached 100% after 9 days of culture with Porostereum spadiceum BS34. Using genomics and proteomics analyses coupled with activity tests, we showed that P. spadiceum produces several heme-peroxidases together with H2O2-producing enzymes that could be involved in the antibiotic biotransformation process. Using UV and high-resolution mass spectrometry, we were able to detect five levofloxacin degradation products. Their putative identity based on their MS2 fragmentation patterns led to the conclusion that the piperazine moiety was the main target of oxidative modification of levofloxacin by P. spadiceum, leading to a decrease in antibiotic activity.

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