Development of strong enzymatic biocatalysts for dye decolorization

Escherichia coli crude laccase was used to develop an immobilized biocatalyst with improved stability. Chelating and entrapment immobilization techniques were studied, and laccase encapsulation in Cu-alginate gels showed the best results. This biocatalyst was active at different conditions of pH, temperature and ionic strength, and was able to decolorize the carcinogenic dyes Trypan Blue, Bromothymol Blue and Coomassie Brilliant blue R with yields close to 90% without mediator addition. The Cu-alginate derivatives retained more than 70% of catalytic activity for at least 430 h of continuous use. The results demonstrated that immobilized laccase has potential applications in dyestuff treatment.