Factors Involved in the Regulation of a Ligninase Activity in Phanerochaete chrysosporium.

The regulation of an H(2)O(2)-dependent ligninolytic activity was examined in the wood decay fungus Phanerochaete chrysosporium. The ligninase appears in cultures upon limitation for nitrogen or carbohydrate and is suppressed by excess nutrients, by cycloheximide, or by culture agitation. Activity is increased by idiophasic exposure of cultures to 100% O(2). Elevated levels of ligninase and, in some cases, of extracellular H(2)O(2) production are detected after brief incubation of cultures with lignins or lignin substructure models, with the secondary metabolite veratryl alcohol, or with other related compounds. It is concluded that lignin degradation (lignin --> CO(2)) by this organism is regulated in part at the level of the ligninase, which is apparently inducible by its substrates or their degradation products.