Immobilization of xylanase on modified grafted alginate polyethyleneimine bead based on impact of sodium cation effect.

Immobilization of xylanase on modified grafted alginate polyethyleneimine bead based on impact of sodium cation effect.

Int J Biol Macromol. 2019 Aug 26;:

Authors: Mostafa FA, El Aty AAA, Hassan ME, Awad GEA

Abstract
Alginate- polyethyleneimine gel beads modified by using 0.3 M Na+ were used for covalent immobilization of Aspergillus flavus xylanase. SEM images showed distorted structure with addition of Na+ that impaired the egg-box structure formation offered much covalent binding with xylanase. Immobilization onto Alg + PEI/Na showed an enhancement in the operational stability, immobilization efficiency as well as immobilization yield. Covalent immobilization of xylanase onto Alg + PEI/Na+ enhanced xylanase activity over a wide range of pHs (4-5.5) comparable to its free formula. As well as an increase in reaction temperature up to 60 °C. However, immobilized formula of enzyme showed abroad thermal stability that it retained 79.0% of its initial activity at 70 °C up to 30 min whereas, free formula completely lost its activity at this temperature. Thermodynamics studies showed an enhancement in thermal stability at high temperature for the immobilized xylanase. i.e. At 70 °C The T1/2 and D-value for free formula of enzyme increased from 24 to165 min and from 79.95to 548.23 min, respectively. Moreover, the enzyme stability enhancement for immobilized formula of xylanase was proved with a remarkable increase in enthalpy and free energy. 93% of the immobilized xylanase activity was retained over 6 weeks of storage at 4 °C.

PMID: 31465802 [PubMed – as supplied by publisher]

Source: Industry