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Urease immobilized on chitosan membrane: Preparation and properties
Author(s) -
Krajewska Barbara,
Leszko Maciej,
Zaborska Wiesawa
Publication year - 1990
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.280480309
Subject(s) - glutaraldehyde , urease , immobilized enzyme , chemistry , membrane , chitosan , michaelis–menten kinetics , covalent bond , chromatography , enzyme , nuclear chemistry , enzyme assay , organic chemistry , biochemistry
Urease was covalently immobilized on glutaraldehyde‐pretreated chitosan membranes. The optimum immobilization conditions were determined with respect to glutaraldehyde pretreatment of membranes and to reaction of glutaraldehyde‐pretreated membranes with urease. The immobilized enzyme retained 94% of its original activity. The properties of free and immobilized urease were compared. The Michaelis constant was about five times higher for immobilized urease than for the free enzyme, while the maximum reaction rate was lower for the immobilized enzyme. The stability of urease at low pH values was improved by immobilization; temperature stability was also improved. The optimum temperature was determined to be 65°C for the free urease and 75°C for the immobilized form. The immobilized enzyme had good storage and operational stability and good reusability, properties that offer potential for practical application.