Abstract: Laccase production by a white-rot fungus Coriolus versicolor was studied under submerged fermentation (condition).The optimal fermentation parameters were as follows:carbon source 1.1 g/L sucrose combined with 1.1 g/L glucose,nitrogen source 1.88 g/L bean cake powder,culture temperature 30℃ and initial pH value 4.5.The activity of laccase reached 18.2 U/mL.The optimum reaction temperature of laccase was 60℃,and laccase was stable when the environmental temperature was below 55℃.Considering the thermal stability of laccase,the suitable temperature for the enzymatic application was 55℃.The laccase produced by C. versicolor could hydrolyze and decolorize aromatic dye.During the decoloration of acid orange dye with laccase,the addition of redox mediators could obviously increase the catalytic ability of the enzyme.The decoloration rate of acid orange dye could reach 96.5% after 5 h,which showed a good application potential in environment protection.

Key words: white-rot fungi, laccase, submerged fermentation, dye decoloration