دراسة تأثير دعائم التقييد في ثباتية انزيم اليوريز المنقى من بذور الحنظل Citrullus colocynthis

Abstract EN

This study revealed that urease was immobilized by entrapment in gelatin and calcium alginate, the ratios of immobilization were 89% and 80% respectively.

The result of immobilized urease characterization showed that the enzyme retained its original activity when it was incubated at 70 ºC for 50 minutes.

The maximum enzyme activity of immobilized enzyme was 80 ºC and the optimum pH of activity was 7.5.

The study revealed that the Km and Vmax of the immobilized enzyme were 181 mM and 225 mM/Min.

respectively, when the urea was used as a substrate.

As for the stability of storage for free and immobilized enzyme, the study showed that the immobilized enzyme by gelatin lost 20% of its activity after 90 days from keeping in phosphate buffer 50 mM, pH 8 at 4 ºC in comparison with free enzyme which lost 50% under the same condition.

The enzyme immobilized by gelatin retained its original activity till the tenth use while the enzyme immobilized by calcium alginate retained its original activity till the fourth use.