ABSTRACT
Biorefineries represent technologies for producing energy, fuels, and chemicals from renewable biomass and securing energy and resources for establishing a sustainable society. Lignocellulosic materials, including woody biomass, are the most abundant renewable resource on earth. Lignin protects polysaccharides in the plant cell wall and confers mechanical strength and high resistance against chemical/biological decomposition to the lignocellulosic materials, like wood. In the delignification system of white-rot fungi, it is known that delignification reactions are carried out by extracellular ligninolytic oxidoreductases and their accessory enzymes. Each white-rot fungus is considered to produce a specific enzyme set with its own balance. In Phanerochaete sordida YK-624, which shows excellent delignification activity, the fungus mainly secretes manganese peroxidase under ligninolytic conditions. Glyoxal oxidase catalyzes oxidation of glyoxal to form glyoxylate and hydrogen peroxide. In white-rot fungi, this enzyme is one of the sources of extracellular hydrogen peroxide required for activation of ligninolytic peroxidases.
