Evidence for a role of manganese peroxidase in the decolorization of Kraft pulp bleach plant effluent by Phanerochaete chrysosporium: Effects of initial culture conditions on enzyme production

Abstract

A role for Mn-peroxidase (MnP) produced by the white rot fungus Phanerochaete chrysosporium growing on Kraft pulp bleach plant was demonstrated. This enzyme, but not lignin peroxidase (LIP), was detected when growing the fungus under pellet form in the effluent. Enzyme production depended on the density of conidial inoculation, a factor, in turn, determining the shape of pellets. Decolorization and MnP production were obtained only when the fungus grew under the form of a fluffy pelleted material. In vitro experiments with purified MnP and LIP, have shown that only MnP has a decolorizing activity, but this was limited to about 25%. Full ‘in vivo’ decolorization, which attain more than 80%, may therefore depend on the production of other enzyme components by the fungus.