A synthetic metalloporphine was immobilized onto a PVA-based and mercapto-grafted solid support,emulating the active site of cytochrome P450.Its ligninolytic peroxidase-like catalytic activity was studied.The coordinated mercapto ligand significantly affected the catalytic features of the catalyst because the oxidation of lignin-model compounds was very slow by comparison with imidazole- and pyridine-coordinated immobilized metalloporphines.Conversely,the catalyst efficiently bleached several industrial dyes and thus demonstrated promising activity for this application.Based on this altered substrate specificity the oxygen-donor catalytic route seems to be more favorable than a single electron oxidation pathway.