Lignin peroxidase (Lip) and manganese peroxidase (MnP) are the major components of the lignin degradation system in the white-rot fungus Phanerochaete chrysosporium. Expression of P. chrysosporium Lip-encoding genes and MnP-encoding genes (mnp) is activated by nutrient nitrogen depletion. Moreover, the expression of mnp requires the presence of Mn2+. Both nitrogen and Mn2+ levels regulate rnnp expression at the transcriptional level.