Isolation and purification of pyranose 2-oxidase from Phanerochaete chrysosporium and characterization of gene structure and regulation.

Pyranose 2-oxidase (POX) was recovered from Phanerochaete chrysosporium BKM-F-1767 solid substrate culture using mild extraction conditions and was purified. (13)C-nuclear magnetic resonance confirmed production of d-arabino-hexos-2-ulose (glucosone) from d-glucose with the oxidase. Peptide fingerprints generated by liquid chromatography-tandem mass spectrometry of tryptic digests and analysis of the corresponding cDNA revealed a structurally unusual sequence for the P. chrysosporium POX. Relatively high levels of pox transcript were detected under carbon-starved culture conditions but not under nutrient sufficiency. This regulation pattern is similar to that observed for lignin peroxidases, manganese peroxidases, and glyoxal oxidase of P. chrysosporium, supporting evidence that POX has a role in lignocellulose degradation.

Phylogenetic relationships of the genus Phanerochaete inferred from the internal transcribed spacer region.

Phanerochaete is a genus of resupinate homobasidiomycetes that are saprophytic on woody debris and logs. Morphological studies in the past indicated that Phanerochaete is a heterogeneous assemblage of species. In this study the internal transcribed spacer (ITS) region of the nuclear ribosomal DNA was used to test the monophyly of the genus Phanerocthaete and to infer phylogenetic relationships of the 24 taxa studied. Maximum parsimony, maximum likelihood, and Bayesian analyses do not support the monophyly of the genus. However, a core group of species represented by Phanerochaete velutina, P. chrysosporium, P. sordida, P. sanguinea and others are closely related and group together in a clade. Other common Phanerochaete species including Phanerochaete rimosa, P. chrysorhiza, P. omnivora, P. avellanea, P. tiberculata, P. flava, and P. allantospora, however, do not cluster with the core Phanerochaete group.