Decolorization of synthetic textile dyes by laccase from newly isolated Trametes hirsuta EDN084 mediated by violuric acid

Abstract

Decolorization of synthetic dyes by laccase produced from newly isolated Trametes hirsuta EDN084 under in-vitro condition was investigated in this study. Partial purification was conducted using ultrafiltration Amicon 10K at 5000 x g for 20 min. Laccase (0.1 U/mL) could decolorize 50% remazol brilliant blue R (RBBR), 47% reactive blue 4 (RBlue4), 51% acid blue 129 (AB129), 21% acid blue 25 (AB25), 40% acid blue 113 (AB113), 11% acid orange 7 (AO7), 2% reactive black 5 (RBlack5), 2% reactive red 120 (RR120), and 85% direct blue 71 (DBlue71) for 4 h. In order to improve the decolorization, the addition of violuric acid (VA), 2, 2, 6, 6-tetramethylpiperidine 1-oxyl (TEMPO), and 1-hydroxybenzotriazole (HBT) were individually assayed. The result showed that decolorization was improved significantly (2 to 30-fold) after the addition of 1 mM VA. This study suggests that mediator VA is suitable for the enhanced decolorization of synthetic dyes by laccase from T. hirsuta EDN084.