Immobilization of Laccase Produced by Pycnoporus sanguineus for Reuse in the Remediation of Catechol

The catechol (1,2-dihydroxybenzene) can be oxidized by enzymatic action, and then turned into quinone. Laccase (EC 1.10.3.2) is an enzyme produced mainly by fungi of white decomposition, which contains copper, and catalyzes the oxidation of phenolic substrates by coupling the reduction of O 2 to water. The aim of this study is to evaluate the reutilization of Alginate Chitosan Laccase (ACL) beads for remediation of the catechol. In this study, the laccase was produced by the fungus Pycnoporus sanguineus. For the immobilization of the enzyme, 2% calcium alginate and the culture supernatant of the fungus cultivation were used. The mixture was dropped into a solution containing 2% CaCl2, for formation of beads. To ensure resistance enabling the reuse the beads, they were immersed in 0.3% chitosan solution. Enzymatic activity, optimum pH and optimum temperature were determined for the ACL beads and free enzyme. For reuse assay, 13 enzymatic cycles were realized, under agitation. As a result, we obtained optimum pH of 5.0 for free enzyme and ACL beads, optimum temperature of 40 °C for free enzyme and 50 °C for ACL beads. In the reuse test, it was shown that after 13 cycles of enzymatic activity, i.e. oxidation of catechol, it was stable until the 7o cycle. It can be concluded that the present study was effective for immobilization of laccase enzyme and oxidation of catechol.