Immobilization of Aspergillus niger lipase on chitosan-coated magnetic nanoparticles using two covalent-binding methods

Abstract

Aspergillus niger lipase immobilization by covalent binding on chitosan-coated magnetic nanoparticles (CMNP), obtained by one-step co-precipitation, was studied. Hydroxyl and amino groups of support were activated using glycidol and glutaraldehyde, respectively. Fourier transform infrared spectrometry, high-resolution transmission electron microscopy and thermogravimetric analysis confirmed reaction of these coupling agents with the enzyme and achievement of a successful immobilization. The derivatives showed activities of 309.5 ± 2.0 and 266.2 ± 2.8 U (g support)(-1) for the CMNP treated with glutaraldehyde and with glycidol, respectively. Immobilization enhanced the enzyme stability against changes of pH and temperature, compared to free lipase. Furthermore, the kinetic parameters K m and V max were determined for the free and immobilized enzyme. K m value quantified for enzyme immobilized by means of glutaraldehyde was 1.7 times lowers than for free lipase. High storage stability during 50 days was observed in the immobilized derivatives. Finally, immobilized derivatives retained above 80% of their initial activity after 15 hydrolytic cycles. The immobilized enzyme can be applied in various biotechnological processes involving magnetic separation.

Characterisation of a “green” lipase from Aspergillus niger immobilised on polyethersulfone membranes

“…The PES-ADS-lipase and PES-COV-lipase were more stable at 45 and 55°C, respectively ( Figure 7B and C). This result was better than that obtained by Osuna et al (2015), who obtained higher thermal stability at 30°C for A. niger lipase immobilised by covalent bonding on chitosan-coated magnetic nanoparticles. In general, the main factors responsible for the thermal stability of enzymes are protein hydrophobicity, the number of hydrogen and disulfide bonds, amino acid composition, and intermolecular interactions of the protein (Yu, Tan, Xiao, & Xu, 2012).…”

Synthesis of structured triacylglycerols enriched in n-3 fatty acids by immobilized microbial lipase

“…An immobilization procedure for A. niger lipase by covalent binding on chitosan-coated magnetic nanoparticles was recently reported. 22 Immobilized derivatives retained above 80% of their initial activity after 15 hydrolytic cycles, and high storage stability during 50 days was observed. Also, lipase from Rhizomucor miehei and M. javanicus immobilized in microemulsion-based organogels maintained good enantioselectivities in the hydrolysis of ketoprofen vinyl ester and their activities increased 12.8-fold and 7.8-fold, respectively, compared with their free forms.…”

Synthesis of functionalized 4H-Chromenes catalyzed by lipase immobilized on magnetic nanoparticles

“…Enzyme immobilization on magnetite nanoparticles (MNPs) has attracted considerable attention recently for its unique advantages for the high specific surface area, low mass transfer resistance and convenient separation from the reaction mixture under a magnetic field (21,22). Many works have been reported that lipase could be immobilized on MNPs to enhance its stability and catalytic activity in enzymatic esterifications or resolutions (23)(24)(25)(26). However, improvement of lipase catalytic performance on MCRs by immobilization on MNPs has not been reported yet.…”