ABSTRACT
Laccase is a multi-copper containing a lignolytic enzyme that catalyses the oxidation of substrates using oxygen from the environment and produces water as a by-product. The biggest advantage of this enzyme is that it requires only oxygen unlike other lignolytic enzymes that require hazardous and expensive hydrogen peroxide and thus do not meet industrial requirements. Laccase is present in all forms of life, such as plants, fungi and bacteria. Laccase was first identified in 1883 by Yoshida in the plant Rhus vernicifera and was designated as a p-diphenol oxidase until 1962. It was identified in 1993 that laccase was involved in the lignification process in plants (O’Malley et al. 1993). Plant laccases have not been well studied due to difficulty in their purification from plant extracts. Fungal laccases are well studied and applied to the industries. Bertrand and Labored recognised laccase as a fungal enzyme in 1896 (Thurston 1994). In the 1980s, laccase was isolated from the fungus Pycnoporous chrysosporium (Tien and Kirk 1983). The first bacterial laccase was found in Azospirillum lipoferum in 1994 (Diamantidis et al. 2000). An extensive search of the bacterial genome database has revealed wide occurrence of the laccase gene in bacteria (Alexandre and Zhulin 2000; Claus 2004).
