Banana skin: A novel waste for laccase production by Trametes pubescens under solid-state conditions. Application to synthetic dye decolouration

In this paper, we investigated the potential of banana skin as a support-substrate for the production of extracellular laccase by the white-rot fungus Trametes pubescens CBS 696.94. Laccase showed a maximum activity of 1570 U/l. In addition, we assessed the degrading ability of the extracellular liquid obtained. For this, we performed the in vitro decolouration of two structurally different dyes such as the anthraquinonic dye Remazol Brilliant Blue R (RBBR) and the triphenylmethane dye Methyl Green (MG). The former was decolourised about 57% in 4 h, whereas the latter presented a lower decolouration rate (40.9% in 4 h). Interestingly, RBBR decolouration was considerably higher than that attained by a commercial laccase (23.2% in 4 h), whereas MG decolouration (46% in 4 h) was very similar for both laccases. This shows the high potential of T. pubescens laccase for synthetic dye decolouration, especially for anthraquinonic dyes.