3.3. Effect of metal ions, pH and temperature on MG decolorization by T. trogii Berk S0301 laccase
In this study, the effects of Mn2+, Mg2+, Ni2+, Ca2+, Cu2+, Zn2+, Co2+, Fe2+, Fe3+ and Na+ on MG decolorization were determined (Fig. 2a). Relative to 96.1% decolorization in the control, Mn2+, Mg2+, Zn2+, Co2+ and Na+ (100 mM) had almost no effect on MG decolorization, with a maximum decolorization of 94.6%, 96.6%, 94%, 89.9% and 91.0% after 8 h, respectively. It should be noted that Cu2+ (100 mM) inhibited MG decolorization, with a maximum decolorization of 77.7% after 3 h and 82.9% after 8 h. Among the metal ions tested, Ni2+ (100 mM), Ca2+ (100 mM) and Fe3+ (1 mM) clearly inhibited MG decolorization, with a maximum decolorization of 51.3%, 53.3% and 66% after 3 h, respectively.