title: Degradation of azo dyes by Trametes villosa laccase over long periods of oxidative conditions.
abstract: Trametes villosa laccase was used for direct azo dye degradation, and the reaction products that accumulated after 72 h of incubation were analyzed. Liquid chromatography-mass spectrometry (LC-MS) analysis showed the formation of phenolic compounds during the dye oxidation process as well as a large amount of polymerized products that retain azo group integrity. The amino-phenol reactions were also investigated by 13C-nuclear magnetic resonance and LC-MS analysis, and the polymerization character of laccase was shown. This study highlights the fact that laccases polymerize the reaction products obtained during long-term batch decolorization processes with azo dyes. These polymerized products provide unacceptable color levels in effluents, limiting the application of laccases as bioremediation agents.
authors.affiliation: University of Minho, Department of Textile Engineering, Campus de Azurém, 4800-058 Guimarães, Portugal.
authors.forename: Andrea
authors.initials: A
authors.lastname: Zille
authors.forename: Barbara
authors.initials: B
authors.lastname: Górnacka
authors.forename: Astrid
authors.initials: A
authors.lastname: Rehorek
authors.forename: Artur
authors.initials: A
authors.lastname: Cavaco-Paulo
mesh_terms: D000627:Aminophenols; D001391:Azo Compounds / Q000378:metabolism*; D001487:Basidiomycota / Q000201:enzymology*; D001673:Biodegradation, Environmental; D004396:Coloring Agents / Q000378:metabolism*; D019281:Dimerization; D008401:Gas Chromatography-Mass Spectrometry; D042845:Laccase / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D010084:Oxidation-Reduction
chemical_list: D000627:Aminophenols; D001391:Azo Compounds; D004396:Coloring Agents; D042845:Laccase