Enhanced pH and thermal stabilities of invertase immobilized on montmorillonite K-10

Abstract

Invertase was adsorbed onto micro-porous acid-activated montmorillonite clay (K-10) by two procedures, namely adsorption and covalent binding. The immobilized enzymes were characterized by XRD, surface area measurements and 27 Al NMR. XRD measurements revealed an expansion of clay layers due to immobilization which suggests that intercalation had taken place. Surface area measurements also support this observation. 27 Al NMR showed that interaction of enzyme with tetrahedral and octahedral Al changes with the immobilization procedure. Sucrose hydrolysis was performed in a batch reactor. The immobilized enzymes showed enhanced pH and thermal stabilities. Optimum pH and temperature were found to increase upon immobilization. The effectiveness factor (g) and Michaelis constant (K m ) suggest that diffusional resistances play a major role in the reaction. The immobilized invertase could be stored in buffer of pH 5 and 6 at 5°C without any significant loss in activity for 20 days.

Stability of Soybean Oil Degumming Using Immobilized Phospholipase A2

“…2, it can be observed that all immobilized enzymes retained more than 80 of their relative activity over a broader temperature range from 45 to 55 with a 10 increase in optimum temperature compared to the free enzyme. Similar observations have reported that the immobilization increased the temperature optimum from 50 to 60 23 . Bornscheuer 25 reported that the shift in optimal temperature toward higher values could be due to the immobilization of the enzyme.…”

Immobilization of β-Galactosidase onto Magnetic Beads

“…One of the main reasons for enzyme immobilization is the anticipated increase in its stability to various deactivating forces due to restricted conformational mobility of the molecules following immobilization. Therefore, the immobilized enzyme could work in harsh environmental conditions with less activity loss compared to the free counterpart [1,[17][18][19].…”

Immobilization of β-galactosidase from Lactobacillus plantarum HF571129 on ZnO nanoparticles: characterization and lactose hydrolysis

“…In contrast to this study, bioaffinity-based immobilization of almond (A. communis) b-galactosidase on Con A-layered calcium alginate-cellulose beads [30] and b-galactosidase (A. oryzae) immobilized on Con A-celite 545 [32] showed that both immobilized and soluble enzyme showed an optimum activity at 50°C. For this reason, the immobilized enzyme could work in wild environmental conditions with less activity loss compared to its soluble counterpart [42][43][44].…”