Figure 5.d) shows. Decolorization time-course of synthetic dyes RB5, by immobilized or free laccase in the presence and absence of redox mediator (HBT, 1 mM). That he immobilized enzyme showed around 31% decolorization in 8 h and 24 h of incubation without HBT. However, decolorization nearly to 1.3-fold by the immobilized enzyme and maximum decolorization of 78.2% was observed within 8 hr.