Abstract:

The effect of various factors on dye decolorization activity of crude laccase enzyme from repeated-batch culture of Funalia trogii ATCC 200800 to obtain rapid and high decolorization activity against Reactive Black 5 and Reactive Blue 171 dyes was investigated. All conditions used were important for dye decolorizing activity of this crude laccase enzyme. The optimum pH of decolorization was tested at 30 °C and it was around 3.0. This activity was highly reduced at pH 4.5-6.0. On the other hand, the optimum temperature for rapid and high decolorization was 50 °C. Importantly, the decolorization rate of crude laccase at pH 4.5 and pH 6.0 increased with the rise in temperature from 30 °C to 50 °C. Therefore, high decolorization could be obtained at pH 4.5 and even pH 6.0 by selecting the proper temperature for these pH values. Enzyme amount also affected the dye decolorization positively. This crude laccase could also decolorize the mixed dyes (Reactive Black 5 and Reactive Blue 171) and synthetic wastewaters. Native polyacrylamide gel electrophoresis showed the responsibility of the laccase enzyme in decolorization. Rapid and high textile dye decolorization through the selection of appropriate conditions could facilitate the development of more economical and environmentally friendly processes.

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