Effect of fungal laccase and new mediators, acetovanillone and acetosyringone, on decolourization of dyes

Several wood rotting fungi decolourized Remazol brilliant blue R (RBBR) and carminic acid (CA). Parallel activity of laccase in these fungi was studied. The addition of acetovanillone (AV) or acetosyringone (AS) intensified these processes: decolourization was more extensive than in the experiment omitting these compounds. At the presence of AS the decourization was more extensive than AV. However the level of destaining was relatively low in comparison to laccase activity on syringaldazine. The highly purified constitutive form of Cerrena unicolor and inducible form of Trametes versicolor laccases also decolourized both dyes. The fungus, Lentinus lepideus, which has no laccase activity did not decolourize at all. Nitrogen starvation induced the laccase and decolourization activity in both organisms, irrespective of nitrogen availability. This fact indicates laccase not solely responsible for decolourization, and probably decolourization of dyes involves more than one mechanism.