Genome sequencing of Porostereum spadiceum to study the degradation of levofloxacin

Amal Ben Ayed (1, 2) , Imen Akrout (1, 2) , Karima Staita (1, 2) , Quentin Albert (1) , Stephane Greff (3) , Charlotte Simmler (3) , Steven Ahrendt (4) , Kurt Labutti (4) , Anna Lipzen (4) , Guifen He (4) , Emily Savage (4) , Jean Armengaud (5) , Mélodie Kielbasa (5) , David Navarro (1) , Elodie Drula (1, 6) , Annick Turbé-Doan (1) , Emmanuel Bertrand (1) , Anne Lomascolo (1) , Delphine Chaduli (1, 6) , Craig Faulds (1) , Mohamed Chamkha (7) , Amina Maalej (7) , Kerrie Barry (4) , Igor Grigoriev (4, 8) , Francis Martin (9) , Héla Zouari-Mechichi (7) , Giuliano Sciara (1) , Tahar Mechichi (7) , Eric Record (1)

1 BBF - Biodiversité et Biotechnologie Fongiques
2 ENIS - École Nationale d'Ingénieurs de Sfax | National School of Engineers of Sfax
3 IMBE - Institut méditerranéen de biodiversité et d'écologie marine et continentale
4 LBNL - Lawrence Berkeley National Laboratory [Berkeley]
5 MTS - Médicaments et Technologies pour la Santé
6 AFMB - Architecture et fonction des macromolécules biologiques
7 Université de Sfax
8 UC Berkeley - University of California [Berkeley]
9 IAM - Interactions Arbres-Microorganismes

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.

Mots clés: Biotransformation; Fluoroquinolone; Fungi; Peroxidases; Hazardous substance

Domaines: Sciences du Vivant [q-bio]

Amal Ben Ayed, Imen Akrout, Karima Staita, Quentin Albert, Stephane Greff, et al.. Genome sequencing of Porostereum spadiceum to study the degradation of levofloxacin. Ecotoxicology and Environmental Safety, 2024, 270, pp.115808. ⟨10.1016/j.ecoenv.2023.115808⟩. ⟨hal-04384257⟩