Removal of phenols from mixtures by co-immobilized laccase/tyrosinase and Polyclar adsorption

An enzymatic method for removal of phenols from their mixtures was investigated. Phenols in an aqueous solution were removed after a two-step treatment with co-immobilized laccase and tyrosinase and Polyclar (polyvinylpolypyrrolidone). A laccase from Pyricularia oryrae and mushroom tyrosinase were co-immobilized on Mikroperl in a fixed-bed tubular bioreactor by a rapid and simple method. The support immobilized 95% of the total laccase units and 35% of the total tyrosinase units. Different mixtures of phenols were passed through the column with co-immobilized laccase and tyrosinase, This method removed 42-90% of different phenolic substances by a single passage through the bioreactor, The second step employed Polyclar for additional removal of phenolic substances from mixtures. The degree of removal depends on the nature of the phenols. Complete removal was achieved for alpha-naphthol, 2,4-dichlorophenol, 4-methoxyphenol, beta-naphthol, 4-chloro-3-methylphenol and catehin. The operational stability of the immobilized system was 10-90 h depending on the substrate. The biocatalyst was capable of continuous transformation of different phenols in mixtures.