Laccase-Mediated Textile Dye Decolorization by Cladosporiumoxysporum

Water polluted by textile industry contain non-biodegradable dyes and various chemical pollutants which when treated by conventional methods still lead to the formation of sludge. In the present study laccase enzymes from Cladosporium oxysporum were used to decolorize Reactive Blue, Reactive Yellow and Reactive Red dyes through adsorption. Immobilized treatment was tried to minimize the cost of enzyme treatment. Also the effect of pH and temperature on dye decolorization was studied. The enzyme was stable at pH 5.0 and retained 90.34 % activity after 240 min. The enzyme was stable at 40C and retained 92.87 % activity after 1 hour. Decolorization for free enzyme was 41.90, 34.18 and 27.87 % respectively for Reactive Blue, Reactive Yellow and Reactive Red while for immobilized enzymes was 61.20, 50.51 and 39.34 %. The increased level of decolorization by immobilized enzyme was attributed to initial adsorption on solid material and enzyme degradation in the later phase. The present study revealed that Cladosporium oxysporum at optimum conditions could be effectively used for treatment of dye industry effluent.