Immobilization of Phytase from Rice Bean (Vigna umbellata Thunb.) on Glutaraldehyde Activated Chitosan Microspheres

Abstract

The immobilization of phytase from rice bean was optimized on the glutaraldehyde-activated chitosan microsphere, and characterized. The optimum percent immobilization was 77.48%, when microspheres were prepared with 1.5% chitosan, activated with glutaraldehyde (0.5%, for 4 h) and with the enzyme protein (0.2 mg/mL, and coupling time 4 h). The immobilized phytase exhibited elongated fibres and pores. FTIR results suggest the formation of a Schiff base with a band at 1638 cm-1. The pH and temperature optimum of immobilized phytase was 4.0 and 40 °C, respectively. The energy of activation was 34.5 kJ/mol. The Km and Vmax values of immobilized phytase were 0.62 mM and 3.42 μmol/min. The immobilized enzyme when incubated at 50 °C, retained 59% activity after 75 min. The immobilized phytase showed 80% activity retention, after 14 days, when stored at 4 °C. The immobilized phytase could be reused for 4 cycles with 58% activity retention. The immobilized phytase, when incubated for 60 min in the presence trypsin and pepsin, showed 92.9 and 95% activity retention, respectively. The properties of immobilized phytase did not alter with respect to pH, and temperature optima. Immobilized phytase exhibited proteolytic resistance when incubated with pepsin for 1 h, and this can find application in animal feed.

Photosensitive Polymeric Janus Micromotor for Enzymatic Activity Protection and Enhanced Substrate Degradation

“…The spherical morphology, diameter size, and cross-linking of CH with glutaraldehyde of J-PCMs allow high surface and support area 72 available for protein linking. The J-PCMs based on the CH biopolymer provide hydrophilicity, biodegradability, 73 and biocompatibility. 74 The J-PCM protein immobilization ability was demonstrated by loading an FITC peptide and PB-ST, covalent immobilization, and absorption interaction and taking advantage of the available primary amines from the peptide and C−C affinity, respectively.…”

Biomass-derived functional materials as carriers for enzymes: towards sustainable and robust biocatalysts

“…The storage, thermal, operational, and pH stabilities can be greatly improved for enzymes that are immobilized on the surface of chitosan (Table 5). 156–214 Chitosan-based materials can be produced in different geometrical configurations ( e.g. , microcapsules, membranes, beads/microspheres, coatings, fibers, gels, and sponges), which have shown good storage, thermal/operational stability, and reusability properties.…”