Laccases are phenol-oxidizing, four-copper containing
metalloenzymes [97]. For industrial and biotechnological
purposes, laccases were among the first fungal oxidoreductases
providing larger-scale applications such as
removal of polyphenols in wine and beverages, conversion
of toxic compounds and textile dyes in waste waters,
and in bleaching and removal of lignin from wood
and non-wood fibres [98–100].
Laccases catalyze the oxidation of a variety of phenolic
and lower-redox potential compounds [28–30, 39,
40] with the concomitant reduction of molecular oxygen
to water (Scheme 2). One catalytic cycle involves
several enzyme intermediates [97], and overall 4 e- are
donated by the phenolic substrate compounds (Phe-OH).
The reactive phenoxy radicals (Phe-O