Removal of Aroclor 1254 by the white rot fungus Coriolus versicolor in thepresence of different concentrations of Mn(IV)oxide

Lignin peroxidase (LiP) plays an active role in the biodegradation of ligni n and phenolic structures resembling lignin. The role of other enzymes in t he biodegradation of recalcitrant compounds, e.g. manganese(II)-peroxidase, is uncertain. Solid manganese(IV)oxide addition improved the production of manganese(II)-dependant peroxidase (MnP) and H2O2 and increased the rate o f biodegradation of Aroclor 1254 in a nitrogen-limited medium by the while rot fungus Coriolus versicolor. MnP activity was detected 48 h after the ad dition of MnO2 to the cultures and was absent in cultures that did not rece ive MnO2. The rate of Aroclor 1254 removal by C. versicolor was influenced by the concentration of MnO2. 34.5 mM concentrations only increased the H2O 2 production. Removal of Aroclor 1254 in the absence of MnO2 still took pla ce which implied the presence of (LIP) or nonspecific absorption. The cultu res containing 57.5 mM MnO2 removed ca. 84% of the initial 750 mg l(-1) Aro clor in 6 days of incubation. Cultures with no MnO2 and 34.5 mM removed 79 and 76%, respectively. Cultures with MnP or LIP as the dominant enzyme spec ies removed penta- and hexachlorobiphenyls at a slower rate than tri- and t etrachlorobiphenyl. (C) 2000 Elsevier Science Ltd. All rights reserved.