Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Outlines of an “exploding” network of metabolites generated from the fluoroquinolone enrofloxacin by the brown rot fungus Gloeophyllum striatum

  • 265 Accesses

  • 37 Citations


Degradation of the veterinary fluoroquinolone antibiotic enrofloxacin (EFL) was studied with three strains of Gloeophyllum, basidiomycetous fungi thought to produce extracellular hydroxyl radicals. Metabolites generated in a mineral medium were analyzed by combined high-performance liquid chromatography/high-resolution electrospray ionization mass spectrometry. Their origin was inferred from peak doublets representing 12C and 14C isotopomers detected at a defined proportion. From each exact molecular mass, the molecular formula was derived for which the most probable chemical structure was postulated, using for guidance 18 known EFL metabolites. All supernatants provided similar metabolite patterns, with the most comprehensive consisting of 87 compounds. These metabolites belonged to five families headed by EFL, its oxidatively decarboxylated or defluorinated congeners, an isatin-, and an anthranilic acid-type derivative. Metabolites hydroxylated in the aromatic part suggested the formation of three catechols and two oxidizable ortho-aminophenol-type compounds. After oxidation to the respective ortho-quinones or ortho-quinone imines and oxidative ring cleavage at one of three alternative sites, the formation of various cis,cis-muconic acid-type derivatives is likely, one of which could be detected. Anthranilic acid-type compounds provided two additional sites for ortho-aminophenol formation and aromatic ring cleavage. An “exploding” network of diverse EFL congeners produced by Gloeophyllum suggests the broad utility of our model for studying biodegradation.

This is a preview of subscription content, log in to check access.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6


  1. Backa S, Gierer J, Reitberger T, Nilsson T (1993) Hydroxyl radical activity associated with the growth of white-rot fungi. Holzforschung 47:181–187

  2. Bagley ST, Richter DL (2002) Biodegradation by brown rot fungi. In: Osiewacz HD (ed) The mycota, vol 10. Springer, Berlin Heidelberg New York, pp 327–341

  3. Baykut G, Fuchser J, Witt M, Weiss G, Gosteli C (2002) A combined ion source for fast switching between electrospray and matrix-assisted laser desorption/ionization in Fourier transform ion cyclotron resonance mass spectrometry. Rapid Commun Mass Spectrom 16:1631–1641

  4. Chen Y, Rosazza JPN, Reese CP, Chang H-Y, Nowakowski MA, Kiplinger JP (1997) Microbial models of soil metabolism: biotransformations of danofloxacin. J Ind Microbiol Biotechnol 19:378–394

  5. Cohen R, Jensen KA Jr, Houtman CJ, Hammel KE (2002) Significant levels of extracellular reactive oxygen species produced by brown rot basidiomycetes on cellulose. FEBS Lett 531:483–488

  6. Cohen R, Suzuki MR, Hammel KE (2004) Differential stress-induced regulation of two quinone reductases in the brown rot basidiomycete Gloeophyllum trabeum. Appl Environ Microbiol 70:324–331

  7. Dalhoff A, Bergan T (1998) Pharmacokinetics of fluoroquinolones in experimental animals. In: Kuhlmann J, Dalhoff A, Zeiler H-J (eds) Quinolone antibacterials. Springer, Berlin Heidelberg New York, pp 179–206

  8. Field JA (2003) Biodegration of chlorinated compounds by white rot fungi. In: Häggblom MM, Bossert ID (eds) Dehalogenation. Microbial processes and environmental application. Kluwer, pp 159–204

  9. Halliwell B, Gutteridge JMC (1999) Free radicals in biology and medicine, 3rd edn. Oxford University Press, Oxford

  10. Hyde SM, Wood P (1997) A mechanism for production of hydroxyl radicals by the brown-rot fungus Coniophora puteana: Fe(III) reduction by cellobiose dehydrogenase and Fe(II) oxidation at a distance from the hyphae. Microbiology 143:259–266

  11. Jensen KA Jr, Houtman CJ, Ryan ZC, Hammel KE (2001) Pathways for extracellular Fenton chemistry in the brown rot basidiomycete Gloeophyllum trabeum. Appl Environ Microbiol 67:2705–2711

  12. Jensen KA Jr, Ryan ZC, Vanden Wymelenberg A, Cullen D, Hammel KE (2002) An NADH:quinone oxidoreductase activity during biodegradation by the brown rot basidiomycete Gloeophyllum trabeum. Appl Environ Microbiol 68:2699–2703

  13. Kamada F, Abe S, Hiratsuka N, Wariishi H, Tanaka H (2002) Mineralization of aromatic compounds by brown-rot basidiomycetes—mechanisms involved in initial attack on the aromatic ring. Microbiology 148:1939–1946

  14. Kerem Z, Jensen KA, Hammel KE (1999) Biodegradative mechanism of the brown rot basidiomycete Gloeophyllum trabeum: evidence for an extracellular hydroquinone-driven Fenton reaction. FEBS Lett 446:49–54

  15. Kramer C, Kreisel G, Fahr K, Käßbohrer J, Schlosser D (2004) Degradation of 2-fluorophenol by the brown-rot fungus Gloeophyllum striatum: evidence for the involvement of extracellular Fenton chemistry. Appl Microbiol Biotechnol 64:387–395

  16. Luu Y, Ramsay BA, Ramsay JA (2003) Nitriloacetate stimulation of anaerobic Fe(III) respiration by mobilization of humic material in soil. Appl Environ Microbiol 69:5255–5262

  17. Martens R, Wetzstein H-G, Zadrazil F, Capelari M, Hoffmann P, Schmeer N (1996) Degradation of the fluoroquinolone enrofloxacin by wood-rotting fungi. Appl Environ Microbiol 62:4206–4209

  18. Parshikov IA, Freeman JP, Lay JO Jr, Beger RD, Williams AJ, Sutherland JB (1999) Regioselective transformation of ciprofloxacin to N-acetylciprofloxacin by the fungus Mucor ramannianus. FEMS Microbiol Lett 177:131–135

  19. Pasczynski A, Crawford R, Funk D, Goodell B (1999) De novo synthesis of 4,5-dimethoxycatechol and 2,5-dimethoxyhydroquinone by the brown rot fungus Gloeophyllum trabeum. Appl Environ Microbiol 65:674–679

  20. Paul EA, Clark FE (1996) Soil microbiology and biochemistry, 2nd edn. Academic, San Diego

  21. Schlosser D, Fahr K, Karl W, Wetzstein H-G (2000) Hydroxylated metabolites of 2,4-dichlorophenol imply a Fenton-type reaction in Gloeophyllum striatum. Appl Environ Microbiol 66:2479–2483

  22. Stevenson FJ (1994) Humus chemistry. Genesis, composition, reactions, 2nd edn. Wiley, New York

  23. Varela E, Mester T, Tien M (2003) Culture conditions affecting biodegradation components of the brown-rot fungus Gloeophyllum trabeum. Arch Microbiol 180:251–256

  24. Wang W, Gao PJ (2003) Function and mechanism of a low-molecular-weight peptide produced by Gloeophyllum trabeum in biodegradation of cellulose. J Biotechnol 101:119–130

  25. Wetzstein H-G, Schmeer N, Karl W (1997) Degradation of the fluoroquinolone enrofloxacin by the brown rot fungus Gloeophyllum striatum: identification of metabolites. Appl Environ Microbiol 63:4272–4281

  26. Wetzstein H-G, Stadler M, Tichy H-V, Dalhoff A, Karl W (1999) Degradation of ciprofloxacin by basidiomycetes and identification of metabolites generated by the brown rot fungus Gloeophyllum striatum. Appl Environ Microbiol 65:1556–1563

  27. Wetzstein H-G, Karl W, Hallenbach W, Himmler T, Petersen U (2000) Residual antibacterial activity of metabolites derived from the veterinary fluoroquinolone enrofloxacin. In: Abstracts, 100th General Meeting of the American Society for Microbiology p 2, abstract A-8

  28. Wetzstein H-G, Schneider J, Karl W (2005) Patterns of metabolites produced from the fluoroquinolone enrofloxacin by basidiomycetes indigenous to agricultural sites. Appl Microbiol Biotechnol DOI 10.1007/s00253-005-0178-4

  29. Wood PM (1994) Pathways of production of Fenton reagent by wood-rotting fungi. FEMS Microbiol Rev 13:313–320

  30. Wood TM, Garcia-Campayo V (1994) Enzymes and mechanisms involved in microbial cellulolysis. In: Ratledge C (ed) Biochemistry of microbial degradation. Kluwer, Dordrecht, pp 197–231

  31. Xu G, Goodell B (2001) Mechanisms of wood degradation by brown-rot fungi: chelator-mediated cellulose degradation and binding of iron by cellulose. J Biotechnol 87:43–57

Download references


The technical assistance of A. Lagojda, Bayer CropScience AG, in recording the HRMS spectra is gratefully acknowledged. We thank P. Wood, Bristol, UK, and J. Wesener, Bayer Industry Services, Leverkusen, for advice.

Author information

Correspondence to H.-G. Wetzstein.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Karl, W., Schneider, J. & Wetzstein, H. Outlines of an “exploding” network of metabolites generated from the fluoroquinolone enrofloxacin by the brown rot fungus Gloeophyllum striatum . Appl Microbiol Biotechnol 71, 101–113 (2006). https://doi.org/10.1007/s00253-005-0177-5

Download citation


  • Piperazine
  • Enrofloxacin
  • Oxidative Cleavage
  • Oxidative Decarboxylation
  • Piperazine Ring