Characterization of immobilized laccase from Lentinula edodes and its use in olive-mill wastewater treatment

This study is mainly concerned with the characterization of an immobilized laccase from the white-rot fungus Lentinula edodes for use in wastewater tr eatment. The enzyme was immobilized on chitosan by adsorption and subsequen t cross-linking with glutaraldehyde. The immobilized laccase displayed a lo wer specific activity and a lower substrate affinity than the free enzyme. Nevertheless, the immobilized catalyst exhibited an appreciable catalytic c apability (520 units g(-1) support) along with remarkably improved stabilit y properties to various parameters, such as temperature, pH and storage tim e. The treatment of olive mill wastewater with immobilized laccase led to a partial decolorization as well as to significant abatements in its content in polyphenols, ortho-diphenols combined with a decreased toxicity of the effluent. (C) 1999 Elsevier Science Ltd. All rights reserved.