Induction, purification, and characterization of a laccase isozyme from Pleurotus sajor-caju and the potential in decolorization of textile dyes

Ferulic acid causes a strain of Pleurotus sajor-caju to excrete large amounts of one laccase isozyme, that was purified to homogeneity. Ferulic acid was the best inductor for laccase in this fungal strain. Laccase molecular weight, copper, and sugar content were characterized. Its catalytic activity was studied using a wide range of phenolics and aromatic amines; the purified laccase was found to be able to oxidize catechols, quinols, methoxyphenols, some aromatic amines and their methyl derivatives, and also resorcinol and phloroglucinol. In addition, its thermostability and activity in the presence of some organic solvents were evaluated. The ability of the enzyme to decolorize some textile dyes was studied, also in the presence of the co-oxidizer hydrogen peroxide, and compared to that of some peroxidases.

Figure optionsDownload as PowerPoint slideResearch highlights▶ Ferulic acid was the best laccase inductor among the several tested. ▶ The enzyme showed a very wide substrate specificity. ▶ The enzyme potential for decolorization of industrial dyes was outlined. ▶ The enzyme was stable against some organic solvents, pH and temperature variations.