Veratryl alcohol as a mediator and the role of radical cations in lignin biodegradation by <i>Phanerochaete chrysosporium</i>

Abstract

The oxidative capacity of the ligninase from Phanerochaete chrysosporium toward monomethoxylated and dimethoxylated aromatic compounds was investigated. Phenylacetic acid derivatives were shown to be decarboxylated by the ligninase, via C‐C bond cleavage. Dimethoxylated substrates were much more readily oxidised by the ligninase than were monomethoxylated derivatives, but oxidation of the latter could be stimulated by catalytic amounts of 1,4‐dimethoxybenzene or veratryl alcohol. A mechanism based upon the ability of radical cations to function as one‐electron oxidants is described. The role of redox mediators in lignin degradation, and the biological significance of veratryl alcohol as a secondary metabolite of P. chrysosporium are discussed.