Different fungal manganese-oxidizing peroxidases:: a comparison between Bjerkandera sp and Phanerochaete chrysosporium

Two manganese-oxidizing peroxidases differing in glycosylation degree were purified from fermenter cultures of Bjerkandera sp. They were characterized and compared with the three manganese-oxidizing peroxidase isoenzymes obtained from the well-known ligninolytic fungus Phanerochaete chrysosporium. All the enzymes showed similar molecular masses but those from P. chrysosporium had less acidic isoelectric point. Moreover, the latter strictly required Mn2+ to oxidize phenolic substrates whereas the Bjerkandera peroxidases had both Mn-mediated and Mn-independent activity on phenolic and non-phenolic aromatic substrates. Taking into account these results, and those reported for Bjerkandera andusta and different Pleurotus species, we concluded that two different types of Mn2+-oxidizing peroxidases are secreted by ligninolytic fungi. (C) 2000 Elsevier Science B.V. All rights reserved.