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

Autor: Mostafa FA; Chemistry of Natural and Microbial Products Department, National Research Centre, El Behouth Street, Cairo, 12622, Egypt., El Aty AAA; Chemistry of Natural and Microbial Products Department, National Research Centre, El Behouth Street, Cairo, 12622, Egypt; Department of Biology, Collage of Science, University of Hafr Al Batin, P.O. Box 1803, Hafr Al Batin, Saudi Arabia., Hassan ME; Chemistry of Natural and Microbial Products Department, National Research Centre, El Behouth Street, Cairo, 12622, Egypt; Center of Excellence, Encapsulation & Nano Biotechnology Group, National Research Centre, El Behouth Street, Cairo, 12622, Egypt., Awad GEA; Chemistry of Natural and Microbial Products Department, National Research Centre, El Behouth Street, Cairo, 12622, Egypt. Electronic address: ghadaawad18@yahoo.com.
Jazyk: angličtina
Zdroj: International journal of biological macromolecules [Int J Biol Macromol] 2019 Nov 01; Vol. 140, pp. 1284-1295. Date of Electronic Publication: 2019 Aug 26.
DOI: 10.1016/j.ijbiomac.2019.08.211
Abstrakt: 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 t 1/2 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.
(Copyright © 2019. Published by Elsevier B.V.)
Databáze: MEDLINE
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