Laccase (EC 1:10: 3:2) is multicopper enzyme, belongs to the group of enzymes known as blue oxidases, which catalyzes the oxidation of a wide variety of organic compounds, polyphenols and aromatic amines. Laccase (AUMC 14100 gb, Accession No. MN219732) was purified from P. chrysogenum. The purification process included 85% ammonium sulphate precipitation, DEAE-Cellulose and Sephadex G-200. The specific activity and the fold of purification were 250 units mg-1 protein and 166.7-fold. The yield of purification was 57.6 from Sephadex G200 fraction. The results revealed that laccase stability at 60ºC was enhanced in presence of sorbitol and mannitol as polyols was enhanced gradually in a concentration-dependent manner. Also, the enzyme stability in presence of raffinose was higher than that recorded with sucrose, maltose and xylose, respectively. This enhancement of the enzyme stability by such additives is critical results for industrial application of laccase.
Key words: Laccase, P. chrysogenum, Purification, Thermostability, Polyols, Raffinose.
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