Abstract: Trametes sp. 4281 is a new type of highly efficient laccase production strain independently screened and identified in the laboratory.In order to explore the potential of laccase to decolorize dye, crude Trametes sp. 4281 laccase solution was used to decolorize three categories of dyes, i.e. azo, anthraquinone and phenylmethane. The effects of different mediums, temperatures, pHs, medium concentration, enzyme amount, reaction times and metal ions on the dye decolorization were investigated. The results showed that addition of mediators had a significant influence on the decolorization efficiency; the six dyes were almost completely decolorized within 8 h, with the decolorization rates of reactive blue, alizarin red, methyl orange and crystal violet under the optimum reaction conditions reaching 93.9%, 92.3%, 90% and 90%, and those of Congo red, fuchsin reaching 76.6% and 75%, respectively. Mn2+ and high concentrations of Fe2+ had inhibitory effect on the decolorization, while in the presence of metal ions of Na+, Mg2+, Cu2+ Ni2+, and Zn2+ the laccase remained high decolorization rates to the dyes. The results suggest that Trametes sp. 4281 laccase has great application potential in the dye decolorization, and has a good prospect in the treatment of environmental wastewater.

Key words: laccase, decolorization, anthraquinone dyes, azo dyes, phenylmethane dyes