Journal of Biotechnology 77 (2000) 235 – 245 Different fungal manganese-oxidizing peroxidases: a comparison between Bjerkandera sp. and Phanerochaete chrysosporium C. Palma a , A.T. Martı ´nez b , J.M. Lema a , M.J. Martı ´nez b, * a Department of Chemical Engineering, Uniersity of Santiago de Compostela, Santiago de Compostela, Spain b Centro de Inestigaciones Biolo ´gicas, Consejo Superior de Inestigaciones Cientı ´ficas, Vela ´zquez 144, E-28006 Madrid, Spain Received 17 June 1999; received in revised form 11 October 1999; accepted 20 October 1999 Abstract 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 Mn 2 + 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 adusta and different Pleurotus species, we concluded that two different types of Mn 2 + -oxidizing peroxidases are secreted by ligninolytic fungi. © 2000 Elsevier Science B.V. All rights reserved. Keywords: Mn-oxidizing peroxidases; Catalytic properties; Bjerkandera sp.; Phanerochaete chrysosporium www.elsevier.com/locate/jbiotec 1. Introduction In order to depolymerize lignin some fungi have developed an unspecific system including the ligni- nolytic enzymes laccase, lignin peroxidase (LiP) and manganese peroxidase (MnP), together with oxidases that provide H 2 O 2 for peroxidase activity (Shimada and Higuchi, 1991). This enzymatic sys- tem is also able to degrade aromatic pollutants causing environmental problems (Barr and Aust, 1994). The exact role of the different ligninolytic enzymes in these degradation processes remains uncertain, mainly due to the possibility to catalyze similar reactions under specific conditions. Phanerochaete chrysosporium, a model organ- ism for lignin and xenobiotic biodegradation stud- ies, produces a family of LiP and MnP isoenzymes (Holzbaur et al., 1991), glyoxal-oxi- dase (Kersten et al., 1995), and multiple laccase isoforms (Dittmer et al., 1997). Bjerkandera spe- cies are able to bleach Kraft pulp (Moreira et al., 1997a) and degrade aromatic hydrocarbons (Field * Corresponding author. Tel.: +34-91-5611800; fax: +34- 91-5627518. E-mail address: mjmartinez@cib.csic.es (M.J. Martı ´nez) 0168-1656/00/$ - see front matter © 2000 Elsevier Science B.V. All rights reserved. PII:S0168-1656(99)00218-7