Immobilization of tyrosinase on chitosan–clay composite beads

• Published in: International journal of biological macromolecules 2012-04, Vol.50 (3), p.815-820
• Main Authors: Dinçer, Ayşe, Becerik, Seda, Aydemir, Tülin
• Format: Article
• Language: English
• Subjects: Agaricales - enzymology; Aluminum Silicates - chemistry; Chitosan; Chitosan - chemistry; Clay; Composite beads; crosslinking; Enzymes, Immobilized - chemistry; Enzymes, Immobilized - metabolism; Glutaral - chemistry; glutaraldehyde; Hydrogen-Ion Concentration; Immobilization; immobilized enzymes; Kinetics; Microspheres; Monophenol Monooxygenase - chemistry; Monophenol Monooxygenase - metabolism; phenol; Phenol - chemistry; Phenol - isolation & purification; Phenol removal; Temperature; Tyrosinase; Waste Management
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2011.11.020

► The composite beads were prepared by mixing activated clay and chitosan (1:1). ► Glutaraldehyde crosslinked beads were used as supports for immobilization of tyrosinase. ► Present work demostrated a promising application of immobilized tyrosinase for phenol removal. Tyrosinase was immobilized on glutaraldehyde crosslinked chitosan–clay composite beads and used for phenol removal. Immobilization yield, loading efficiency and activity of tyrosinase immobilized beads were found as 67%, 25% and 1400U/g beads respectively. Optimum pH of the free and immobilized enzyme was found as pH 7.0. Optimum temperature of the free and immobilized enzyme was determined as 25–30°C and 25°C respectively. The kinetic parameters of free and immobilized tyrosinase were calculated using l-catechol as a substrate and Km value for free and immobilized tyrosinase were found as 0.93mM and 1.7mM respectively. After seven times of repeated tests, each over 150min, the efficiency of phenol removal using same immobilized tyrosinase beads were decreased to 43%.