Physicochemical and catalytic properties of acylase I from aspergillus melleus immobilized on amino‐ and carbonyl‐grafted stöber silica

Abstract

Acylase I from Aspergillus melleus was immobilized on supports consisting of unmodified and modified silica. Modification was performed using 3-aminopropyltriethoxysilane (APTES) and glutaraldehyde (GA). The effectiveness of immobilization was investigated using the standard Bradford method in addition to a number of physicochemical techniques, including spectroscopic methods (FTIR, Si and C CP MAS NMR), porous structure and elemental analysis, and zeta potential measurement. A determination of catalytic activity was made based on the deacetylation reaction of N-acetyl-l-methionine. Furthermore, the effect of pH and temperature on the catalytic activity of the free and immobilized enzyme, as well as the reusability of the silica-bound aminoacylase, were determined. The immobilized systems demonstrated a high degree of catalytic activity. The best catalytic parameters were those of aminoacylase immobilized on silica modified with APTES (apparent activity 3937 U/g, relative activity 61.6%). © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:767-777, 2018.

Titania-Based Hybrid Materials with ZnO, ZrO2 and MoS2: A Review

“…Sol-gel processes may be used in many branches of industry; for example, in the production of catalysts or catalyst supports [138], optical and electrical sensors [139], and implant coatings [139,140] Recent reports concern the use of the sol-gel method in the process of immobilization of a wide range of organic materials, including enzymes [141,142,143,144].…”

A General Overview of Support Materials for Enzyme Immobilization: Characteristics, Properties, Practical Utility

“…Another advantage of this material is that it can be used in many different forms. Enzymes belonging to many catalytic classes, for example oxidoreductases, transferases, hydrolases and isomerases, have been immobilized with the use of sol-gel silica, fumed silica, colloidal silica nanoparticles and silica gel as supports [17][18][19][20][21]. The biocatalytic systems obtained demonstrate high catalytic activity retention and good thermal and pH resistance.…”

Structure–Activity Relationship of Carbonic Anhydrase Enzyme Immobilized on Various Silica-Based Mesoporous Molecular Sieves for CO2 Absorption into a Potassium Carbonate Solution

“…The FT-IR spectra of free CA, neat carriers, and the immobilized CA enzymes are shown in Figure . The bands at 1090, 799, and 462 cm –1 were attributed to asymmetric stretching, symmetric stretching, and bending Si–O–Si vibration, respectively. ,− Si–OH bending vibration was observed at 950 cm –1 . , The bands related to the N–H, −NH 2 , O–H, C–H of the CA enzyme were observed at 3745, 3408, 3288 and 3072 cm –1 (Figure a). ,, In Figure b–g, it can be seen that after fixing the CA enzyme, the peak at around 1644 cm –1 of all samples was strengthened, and the band at 1644 cm –1 was assigned to the stretching vibration of the imine group (CN) . Also, unlike pure MMS, a small peak was observed at 1567 cm –1 after the immobilized CA enzyme.…”

“…12,48 The bands related to the N−H, −NH 2 , O−H, C−H of the CA enzyme were observed at 3745, 3408, 3288 and 3072 cm −1 (Figure 7a). 22,49,50 In Figure 7b−g, it can be seen that after fixing the CA enzyme, the peak at around 1644 cm −1 of all samples was strengthened, and the band at 1644 cm −1 was assigned to the stretching vibration of the imine group (CN). 50 Also, unlike pure MMS, a small peak was observed at 1567 cm −1 after the immobilized CA enzyme.…”