Lignin peroxidase (LiP) and manganese peroxidase (MnP) activity in Coriolus versicolor 290 reach maximal levels after 8 and 10 days growth respectively. Increases in LIP activity were observed upon supplementation of the medium with veratryl alcohol. The physiology of this strain is quite distinct from that of the better studied Phanerochaete chrysosporium in that extracellular LIP activity is enhanced at carbon levels of 10g/L(-1), This increase in LIP enzyme activity at higher carbon levels appears to be mediated at the transcriptional level, given that lip and mnp mRNA levels mirror the observed enzyme activity levels quite closely.