PREPARATION AND CHARACTERIZATION OF IMMOBILIZED SPORES WITH LACCASE ACTIVITY FROM Bacillus pumilus W3 ON DEAE-CELLULOSE AND THEIR APPLICATION IN DYE DECOLORIZATION

In order to obtain a more stable and reusable immobilized spore laccase for dye decolorization, the spores from Bacillus pumilus W3 were immobilized on diethylaminoethyl cellulose (DEAE-cellulose). Free and immobilized spore laccase retained 34.38% and 46.11% of their initial activity, respectively, after 10 days incubation at pH 9.0. Their residual activity remained at 27.36% and 31.84% after 10 h incubation at 70 °C. Immobilized spore laccase was more stable than free spore laccase in the presence of most organic solvents, metal ions and inhibitors. The tested dyes, including methyl green, methyl red and acid red 1, were removed 86.82%, 78.14% and 88.60%, respectively, by immobilized spore laccase after 24 h at 37 °C, and 74.34% of initial decolorization activity after 7 cycles was retained when it decolorized acid red 1. These properties indicated that immobilized spore laccase may be useful in textile effluent treatment.