Biodecolorization of Textile Dyes by Immobilized Enzymes in a Vertical Bioreactor System

A capacity of immobilized enzymes from Trametes versicolor U97 or Pestalotiopsis sp. NG007 to decolorize three textile dyes was investigated in a vertical bioreactor system. Immobilization was conducted using a double layer of alginate bead (1.5% w/w) and crude enzymes. The effect of mediators: Tween 80, 1-hydroxybenzotriazol (HBT), or 2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) was investigated on decolorization rate. The results showed that application of immobilized enzymes in a vertical bioreactor enhanced the decolorization efficiency of dyes in the order LB16>RRV9>RRN4, respectively. The decolorization rate was accelerated when a mediator TEMPO was used in immobilized enzyme of U97 or a Tween 80 was used in NG007. Reaction with glutaraldehyde (0.6%) for 4 h maintained the longevity and reusability of the beads. The study suggests that double layer immobilized enzyme in a bioreactor system has a terrific potential strategy for treating the textile dye effluents.