Dual utility of a novel, copper enhanced laccase from Trichoderma aureoviridae

Ever since the ability of laccase to oxidize non-phenolic lignin models was described, the oxidative degradation reactions catalyzed by laccase have been widely studied for paper pulp production or detoxification of aromatic pollutants. The viability of developing eco-friendly, laccase aided industrial processes has been explored. Here, we report the isolation and screening of fungi to explore their lignolytic ability on solid media using various substrates as indicators. The promising fungus was cultivated in submerged and solid state conditions. The crude enzyme obtained yielded elevated activity at 75°C and pH 9.0. Addition of CuSO4 increased the activity by almost 25% proving that Cu(2+) catalytically enhances the action of laccases. Decolorization studies were carried out using industrial dye, Remazol Brilliant Blue R (CI 61200) on solid and liquid medium. Visual decolorization was observed within 2 days of inoculation on solid media whereas, liquid medium incorporated with varying concentrations of dye solution showed a final level of decolorization of up to 76%. Bamboo degradation studies revealed a decrease in lignin content by 51 and 43% within a month. To the best of our knowledge, this study for the first time reports that Trichoderma aureoviridae can produce lignolytic enzyme and degrade lignin.