Furthermore, the decolorization levels of RBBR did not improve by
adding 1 mM of HBT (Fig. 5a). The above results are supported by
Mechichi et al. (2006), who emphasized no effect of the redox
mediator HBT at concentrations between 0.125 and 2.5 mM on the
decolorization of RBBR. Other results also reported that the
oxidation of RBBR was easily carried out by laccase alone