Role of Veratryl Alcohol in Regulating Ligninase Activity in Phanerochaete chrysosporium

Ligninase activity in Phanerochaete chrysosporium is stimulated by incubating cultures with various substrates for the enzyme, including veratryl (3,4-dimethoxybenzyl) alcohol, which is a secondary metabolite of this fungus. This study was designed to provide insight into the mechanism involved in this stimulation. Ligninase activity increased 2 to 4 h after the addition of exogenous veratryl alcohol to ligninolytic cultures. This increase was prevented by inhibitors of protein synthesis. Analysis of the extracellular proteins by high-performance anion-exchange liquid chromatography revealed increases in the amounts of some, but not all, ligninase species. The normal rapid decrease in ligninase activity in aging cultures was not prevented or retarded by veratryl alcohol, indicating that veratryl alcohol does not increase ligninase activity by protecting extant enzyme. We conclude that veratryl alcohol probably functions via an induction type of mechanism, affecting only certain ligninase species. Results with an isolated lignin indicate that lignin (or its biodegradation products) functions in the same way that veratryl alcohol does.