Degradation of Dyes by Laccase

Abstract

The goal of this study was to determine the optimum conditions for the enzymatic decolorization of eleven dyes by laccase. The dyes Cibacron Orange P-4 R, Direct Black VSF 600, Cibacron Red P-4B, Remazol Red, Burdirect Brown M, Burdirect Black Metakonz, Burdirect Dark Blue BH, Burdirect Blue 6B, Cibacron Black PSG, Burdirect Green B, and Remazol Turquoise Blau G133 were characterized spectrophotometrically. The dye that had the highest degree of decolorization (97%), Cibacron Orange P-4 R, was selected for further study. Optimum conditions for decolorization were a 1 mM initial dye concentration at pH 7.0 and an initial enzyme activity of 0.084 U at 25°C for 135 min. Sodium sulfate was selected as the activator at 50 mM. The decolorized products were characterized by infrared spectroscopy and gas chromatography–mass spectrometry. No degradation products were identified following removal of 97% of the dye. © 2016, Copyright © Taylor & Francis Group, LLC.