Laccase production by Trametes hirsuta, characterization, and its capability of decoloring chlorophyll

The present study focused on laccase production, characterization, and its involvement in chlorophyll decolorization. Extracellular laccase, with the highest activity of 11 U/ml on day 8, was efficiently produced from Trametes hirsuta in 5 l bioreactor with optimized media comprising dual carbon sources, glucose and water hyacinth. A laccase was then purified from the supernatant to homogeneity with purification fold of 9.51 and recovery of 39.8% and an estimated molecular mass of 62 kDa by SDS-PAGE. The laccase showed activity at pH 2-6 and temperature 30-80°C and was relatively thermally stable at below 70°C and neutral pH. The laccase was applied to decolorize chlorophyll under different factors: temperature, pH, mediator, metal ions, and enzyme dosage. Other fungal laccases were also found to be able to degrade chlorophyll with rating from 52% to 88% following 1 h treatment with two laccase dosages (5 or 10 U/ml) in the absence of any other mediators at room temperature. These findings may be an important step in developing new, important, and commercially viable industrial applications for laccase enzymes.