Azonaphthalene dyes decolorization and detoxification by laccase from Trametes versicolor

Abstract

The aim of the present study was to investigate the dye decolorization ability of laccase from Trametes versicolor. Five azonaphthalene dyes (Acid Violet 7, Acid Red 1, Allura Red AC, Orange G and Sunset Yellow FCF) were used to evaluate dye decolorization. Laccase from T. versicolor is capable of decolorizing dyes, namely Acid Violet 7 (53.7±2.3 %) and Orange G (46.0±2.2 %). The less effective ability of laccase was observed at the decolorization of other selected dyes (6.9 - 18.6 %). The presence of redox mediator (1-hydroxybenzotriazole) increased decolorization percentage for all tested dyes (≥ 90.5 %). Toxic effect of azo dyes and their degradation products after laccase treatment was observed on the growth of selected bacteria (Micrococcus luteus, Bacillus subtilis, Pseudomonas syringae and Escherichia coli), yeasts (Candida parapsilosis and Saccharomyces cerevisiae) and algae (Chlorella vulgaris and Microcystis aeruginosa). It was confirmed that degradation products showed lower inhibition effect compared to initial dyes. These findings suggest that laccase from T. versicolor are able to decolorize and detoxify selected azonaphthalene dyes.