Preparation and characterization of kappa-carrageenan immobilized urease

Baysal Ş. , Karagoz R.

PREPARATIVE BIOCHEMISTRY & BIOTECHNOLOGY, vol.35, no.2, pp.135-143, 2005 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 35 Issue: 2
  • Publication Date: 2005
  • Doi Number: 10.1081/pb-200054734
  • Page Numbers: pp.135-143


Urease was encapsulated within K-carrageenan beads. Various parameters, such as amount Of K-carrageenan and enzyme activity, were optimized for the immobilization of urease. Immobilized urease was thoroughly characterized for pH, temperature, and storage stabilities and these proper-ties were compared with the free enzyme. The free urease activity quickly decreased and the half time of the activity decay was about 3 days at 4 degrees C. The immobilized urease remained very active over a long period of time and this enzyme lost about 70.43% of its orginal activity over the period of 26 days for storage at 4 degrees C. The Michaelis constant (K-m) and maximum reaction velocity (V-max) were calculated from Lineweaver-Burk plots for both free and immobilized enzyme systems. V-max = 227.3 U/mg protein, K-m = 65.6 mM for free urease and V-max = 153.9 U/mg protein, K-m = 96.42 mM for immobilized urease showed a moderate decrease of enzyme specific activity and change of substrate affinity.