Decolorization of textile dyes by partially purified Pleurotus ostreatus laccase

Abstract

Pleurotus ostreatus produced 2.93 U/mg of laccase in solid state fermentation (SSF) using barley bran as substrate under optimum conditions. The optimum SSF conditions were: pH 6.5; temperature, 25Cº; inoculums size 3.5 mm and moisture content, 1:1.5 w/v. Laccase was partially purified 8.29 fold with specific activity 17.5 U/mg by ion exchange chromatography after curd enzyme concentrated by dialysis against the solid sucrose. Partially purified laccase had an optimum pH of 6.5 and was stable in the pH range from 6.5 to 7.5. The optimum temperature was 45 Cº and it displayed considerable stability within the range 15 to 45 Cº with 1h incubation as well as The ability of partial purified laccase to decolorize of textile dyes showed that the blue H3R dye was completely decolorized in all concentrations within first min while yellow FG and red 3B dyes were decolorized in different percentage.