Degradation of azo dyes by trametes villosa laccase over long periods of oxidative conditions

摘要

Trametes villosa laccase was used for direct azo dye degradation, and the reaction products that accumulatedafter 72 h of incubation were analyzed. Liquid chromatography-mass spectrometry (LC-MS) analysis showedthe formation of phenolic compounds during the dye oxidation process as well as a large amount of polymerizedproducts that retain azo group integrity. The amino-phenol reactions were also investigated by 13C-nuclearmagnetic resonance and LC-MS analysis, and the polymerization character of laccase was shown. This studyhighlights the fact that laccases polymerize the reaction products obtained during long-term batch decolorizationprocesses with azo dyes. These polymerized products provide unacceptable color levels in effluents,limiting the application of laccases as bioremediation agents.