Immobilization of laccase in kappa-carrageenan based semi-interpenetrating polymer networks

Makas Y. G., KALKAN N., AKSOY S., ALTINOK H., HASIRCI N.

JOURNAL OF BIOTECHNOLOGY, vol.148, no.4, pp.216-220, 2010 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 148 Issue: 4
  • Publication Date: 2010
  • Doi Number: 10.1016/j.jbiotec.2010.05.011
  • Journal Name: JOURNAL OF BIOTECHNOLOGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.216-220
  • Keywords: Semi-IPNs, Immobilized laccase, kappa-Carrageenan, Decolorization, Methyl orange, DYE DECOLORIZATION, GLUCOSE-ISOMERASE, SYNTHETIC DYES, ALGINATE, BEADS, ENTRAPMENT, IPNS
  • Middle East Technical University Affiliated: Yes

Abstract

Laccase enzyme (L) was immobilized by entrapment into semi-interpenetrating polymer networks (semi-IPNs) prepared from kappa-carrageenan with either poly(acrylamide-acrylic acid) [P(AAm-AA)/kappa-car] or poly(acrylamide-itaconic acid) [P(AAm-IA)/kappa-car]. For both systems, immobilized enzymes achieved the same optimum values observed for free enzyme (pH = 5.0 and T = 40 degrees C), except for P(AAm-IA)/kappa-car system there was a shift to 5.5 in optimum pH value. At the end of 42 days of storage immobilized enzymes retained more than 80% of their original activities while the retained activities of both systems after 10 uses in batch type application were found to be higher than 50%. K-m values were calculated as 2.52 x 10(-2) mM and 1.08 x 10(-2) mM and V-max values were found as 6.8 x 10(-3) mM min(-1) and 4.4 x 10(-3) mM min(-1), for P(AAm-AA)/kappa-car-L and P(AAm-IA)/kappa-car-L, respectively. When methyl orange containing solutions (10 mg/L) were treated with the immobilized laccases (68.2 U), enzymatic decolorization of methyl orange in 6 h was achieved to the level of 35% for both systems. Supplementing the reaction medium with ABTS as the redox mediator increased this value to about 70%. These initial results show that, laccase containing semi-IPNs can find some applications in decolorization of the industrial wastes. (C) 2010 Elsevier B.V. All rights reserved.