A laccase Gl-LAC-4 purified from white-rot fungus Ganoderma lucidum had a strong ability to degrade and detoxify the alkylphenol pollutants 4-n-octylphenol and 2-phenylphenol.

In this study, the ability of laccase Gl-LAC-4, purified from Ganoderma lucidum, to degrade and detoxify two representative alkylphenol pollutants, 4-n-octylphenol and 2-phenylphenol, was systematically studied. Gl-LAC-4 laccase had a very strong ability to degrade high concentrations of 4-n-octylphenol, 2-phenylphenol, and alkylphenol mixtures. The degradation speed of Gl-LAC-4 toward 2-phenylphenol was very fast. Gl-LAC-4 displayed strong tolerance for a variety of metal salts and organic solvents in the degradation of alkylphenols. Gl-LAC-4 showed strong tolerance for high concentrations of various metal salts, such as MgSO, MnSO, NaSO, CuSO, ZnSO, CdSO, and KSO, in the degradation of 4-n-octylphenol and 2-phenylphenol.In the case of the same metal cation, the inhibitory effect of the metal salt with Cl as the anion on the degradation of 4-n-octylphenol and 2-phenylphenol by laccase was stronger than that of the metal salt with SO as the anion. An increase in the number of chloride ions caused a greater inhibitory effect on alkylphenol degradation by laccase. Gl-LAC-4 exhibited strong tolerance for glycerol, ethylene glycol, butanediol, propylene glycol, and organic solvent mixtures in the degradation of alkylphenols. Gl-LAC-4 treatment significantly reduced or eliminated the phytotoxicity of 4-n-octylphenol and 2-phenylphenol.