A new strain of Bjerkandera sp. production, purification and characterization of versatile peroxidase

8 páginas, 4 figuras, 2 tablas -- PAGS nros. 115-122The lignin modifying enzymes (LMEs) secreted by a new white rot fungus isolated from Chile were studied in this work. This fungus has been identified as a new anamorph of Bjerkandera sp. based on the sequences of the ribosomal DNA and morphological analysis at light microscopy showing hyaline hyphae without clamp connection, cylindrical conidia and lack of sexual forms, similar to those reported in other Bjerkandera anamorphs. The characterization of the culture medium for the highest LMEs production was performed in flask cultures, with a formulation of the culture medium containing high levels of glucose and peptone. The highest Mn-oxidizing peroxidase activity (1,400 U/L) was achieved on day 6 in Erlenmeyer flasks. Four peroxidases (named R1B1, R1B2, R1B3 and R1B4), have been purified by using ion-exchange and exclusion molar chromatographies. All of them showed typical activity on Mn2+ and exhibited Mn-independent activity against 2,6-dimethoxyphenol. R1B4 showed also activity on veratryl alcohol (pH 3) indicating that this enzyme belongs to the versatile peroxidase family. The high VP production capacities of this strain, as well as the enzymatic characteristics of the LMEs suggest that it may be successfully used in the degradation of recalcitrant compoundsThis study has been supported by the Spanish projects S-0505/AMB0100, PGIDIT06PXIB265088PR and CTQ2007-66788, and the European project EUI2008-03703. Authors thanks M. Jurado and B. Casas by your help in ITS analysis and electrophoretic techniques. R. Taboada thanks to BES-2008-006977 PhD fellowship. T. Lu-Chau wishes to thank the Isabel Barreto program from the Galician Government for the economical support provided during the development of this workPeer reviewe