Manganese peroxidase (MnP) is a key enzyme involved in the lignolysis of white-rot fungi. The purpose of this study is to investigate the effect of immobilization and culture conditions on MnP production in cultures of Phanerochaete chrysospodum grown on polyurethane foam. Higher concentrations of foam and lower levels of spore inoculums resulted in the formation of scattered mycelial pellets, increased autolysis of chlamydospore-like cells (a reservoir of MnP), and a higher activity of MnP. Even though MnP was a secondary metabolite, the addition of 5 times more glucose and diammonium tartrate, as carbon and nitrogen sources, resulted in a 4 fold increase in the dry cell mass. However, MnP activity decreased under these conditions to less than half, due to the formation of increasingly dense pellets and the inhibited lysis of chlamydospore-like cells.