Electrostatic immobilization of pectinase on negatively charged AOT-Fe3O4 nanoparticles

An immobilized bifunctional xylanase on carbon-coated chitosan nanoparticles with a potential application in xylan-rich biomass bioconversion

“…The peak at 1556 cm −1 of the immobilized enzyme was assigned as the C N bond formed by Schiff-base reaction between the aldehyde group of glutaraldehyde and the amide in enzyme [28]. The peaks at 2845 and 2914 cm −1 of the immobilized enzyme were attributed to stretching vibration of the CH [27]. The FTIR result indicated that ATXX was immobilized on the obtained carbon-coated chitosan nanoparticles by the C N covalent bond.…”

“…The FTIR spectrum of CNP and immobilized ATXX revealed a broad absorption at 3355 cm −1 , probably attributed to the stretching mode of OH in chitosan and adsorbed water [26]. The two peaks at 1037 and 1154 cm −1 of immobilized ATXX were due to the C O C stretching vibration or C C framework vibration of chitosan [27]. The adsorption peak at 1585 cm −1 of CNP was ascribed to the carbonyl group.…”

“…Bahrami and Hejazi [27] reported that the maximum amount of immobilized pectinase, 610.5 mg enzyme g −1 negatively charged AOT-Fe 3 O 4 , was obtained by electrostatic interaction, and the amount of enzyme immobilization greatly depended on the pH of reaction system. Our previous study showed that Fe 3 O 4 -coated chitosan magnetic nanoparticles showed binding capacity of 162.2 mg g −1 -particles and recovery activity of 56.5% for Aspergillus niger xylanase A [24].…”

Synthesis of a hybrid polymer-inorganic biomimetic support incorporating in situ pectinase from Aspergillus niger ATCC 9642

“…This behavior can be associated with the reduction of viscosity of the solution with increasing temperature, improving the diffusion of substrate to the active site of the immobilized extract through the porous structure of the support [29]. Literature points out that depending on the support, immobilized pectinases present activities in a wide range of pH (4-6) and temperature (37-75°C) [29][30][31][32]. The free pectinolytic extract of A. niger ATCC 9642 showed the maximum activity (72.93 U mL -1 ) at pH 5.5 and 37°C [14].…”

Effects of surface modification and activation of magnetic nanoparticles on the formation of amylase immobilization bonds under different ionic strength conditions

“…For catalytic applications, immobilization through the covalent bond between the enzyme Page 5 of 44 A c c e p t e d M a n u s c r i p t 4 and carrier has been proposed, because the amount of enzyme released from the carrier within the chemical process would be minimum under this condition [6]. However, controlling the immobilization conditions is necessary for reaching the optimum immobilization value and activity of biocatalysts, as the formation of a chemical bond between the enzyme and support, in covalent immobilization method, can potentially cause conformational changes in the structure of the enzyme and variations in its catalytic activity [7].…”