Immobilization of urease by using chitosan-alginate and poly(acrylamide-co-acrylic acid)/kappa-carrageenan supports


Kara F., DEMİREL G., Tumturk H.

BIOPROCESS AND BIOSYSTEMS ENGINEERING, vol.29, no.3, pp.207-211, 2006 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 29 Issue: 3
  • Publication Date: 2006
  • Doi Number: 10.1007/s00449-006-0073-0
  • Journal Name: BIOPROCESS AND BIOSYSTEMS ENGINEERING
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.207-211
  • Keywords: urease, immobilization, interpenetrating polymer networks, polyelectrolyte complex, CONTROLLED-RELEASE, ENZYME, ENCAPSULATION, HYDROLYSIS, STABILITY, MEMBRANE, MATRIX, BEADS
  • Gazi University Affiliated: Yes

Abstract

Jack bean urease (urea aminohydrolase, E.C. 3.5.1.5) was entrapped into chitosan-alginate polvelectrolyte complexes (C-A PEC) and poly(acrylamide-co-acrylic acid)-kappa-carrageenan (P(AAm-co-AA)/carrageenan) hydrogels for the potential use in immobilization of urease, not previously reported. The effects of pH, temperature, storage stability, reuse number, and thermal stability on the free and immobilized urease were examined. For the free and immobilized urease into C-A PEC and P(AAm-co-AA)/carrageenan, the optimum pH was found to be 7.5 and 8, respectively. The optimum temperature of the free and immobilized enzymes was also observed to be 55 and 60 degrees C, respectively. Michaelis-Menten constant (K-m) values for both immobilized urease were also observed smaller than free enzyme. The storage stability values of immobilized enzyme systems were observed as 48 and 70%, respectively, after 70 days. In addition to this, it was observed that, after 20th use in 5 days, the retained activities for immobilized enzyme into C-A PEC and P(AAm-co-AA)/carrageenan matrixes were found as 55 and 89%, respectively. Thermal stability of the free urease was also increased by a result of immobilization.