Role of laccase in lignin degradation by white-rot fungi

Lactase is commonly found in white-rot fungi and catalyses the abstraction of one electron from the phenolic hydroxyl group to polymerize or depolymerize lignin model compounds.Lactase degrades both p-1 and PO-4 dimers via C,-C, cleavage, C, oxidation and alkyl-aryl cleavage.Also, aromatic ring cleavage may be detected following the action of lactase.Lactase can also oxidize non-phenolic compounds when primary mediators, such as 2,2'-azinobis(3_ethyIbenzthiazohne-6sulfonate), are co-present.Lactase produces Mn(III) chelates which allow wood-decaying enzymes to penetrate wood cell walls.Lactase is considered to be capable of degrading lignin together with lignin peroxidase and manganese peroxidase.