Metabolic mechanisms involved in hydroxylation reactions of diphenyl compounds by the lignin-degrading basidiomycete Phanerochaete chrysosporium

Nobuhiro Hiratsuka, Masafumi Oyadomari, Hiroaki Shinohara, Hiroo Tanaka, Hiroyuki Wariishi

Research output: Contribution to journalArticlepeer-review

23 Citations (Scopus)

Abstract

Biphenyl (BP), biphenylene (BN), dibenzofuran (DF), dibenzo-p-dioxin (DD), and diphenyl ether (DE) were utilized as diphenyl substrates for the lignin-degrading basidiomycete, Phanerochaete chrysosporium and its extracellular enzyme, lignin peroxidase (LiP). Among these compounds, only BN and DD were oxidized by LiP. Cyclic voltammetry measurement revealed that BN and DD possess lower redox potentials than other diphenyl substrates utilized, being accordance with a reactivity of LiP. Although the degradations of BP, DF and DE were not extracellularly initiated by LiP, they were metabolized via an intermediate formation of hydroxylated products by intracellular enzymes. Upon addition of piperonyl butoxide, a cytochrome P450 inhibitor, these hydroxylation reactions were effectively inhibited, indicating the involvement of cytochrome P450s. Thus, two individual mechanisms seem to be compulsory for P. chrysosporium to metabolize a wide variety of recalcitrant diphenyl compounds; one is the activation of the aromatic ring via LiP catalyzed one-electron oxidation forming the aryl cation radical and the other is the activation of molecular oxygen by cytochrome P450 enzymes causing hydroxylation reactions on the aromatic ring.

Original languageEnglish
Pages (from-to)241-246
Number of pages6
JournalBiochemical Engineering Journal
Volume23
Issue number3
DOIs
Publication statusPublished - May 1 2005

All Science Journal Classification (ASJC) codes

  • Biotechnology
  • Environmental Engineering
  • Bioengineering
  • Biomedical Engineering

Fingerprint Dive into the research topics of 'Metabolic mechanisms involved in hydroxylation reactions of diphenyl compounds by the lignin-degrading basidiomycete Phanerochaete chrysosporium'. Together they form a unique fingerprint.

Cite this