ACTIVITY AND STABILITY STUDIES OF ULTRAFINE NANOENCAPSULATED CATALASE AND PENICILLINASE

The enzymes catalase (bovine liver, EC 1.11.1.6) and alpha-penicillinase (bacillus cereus strain 569, type I, EC 3.5.2.6) were successfully encapsulated in the polyacrylamide matrix. The encapsulation was carried out in the water pool of water/aerosol OT/n-hexane reverse micelles. The polymeric particles of encapsulated enzymes were reasonably monodisperse and had diameters in the range of several tens of nanometers as measured from quasi-elastic laser light scattering. The activity-pH profile of the encapsulated enzymes in buffer followed the same pattern as that of free enzymes. However, the encapsulated enzymes were found to be less active than their free forms. The enzymes in the encapsulated form were more stable (both thermal stability and shelf-life) as compared to free enzymes. The activity of the encapsulated enzymes was found to be dependent on the degree of cross-linking of the polymer matrix. The greater the cross-linking in the matrix, the lesser were the activity of the encapsulated enzyme.