Synthesis and Characterization of Chitosan/TiO2 Composite Beads for Improving Stability of Porcine Pancreatic Lipase

Abstract

The purpose of the present work is improving stability properties of porcine pancreatic lipase (triacylglycerol lipase, E.C.3.1.1.3) by immobilization on chitosan/TiO2 composite beads. The immobilization parameters were initial enzyme concentration (0.5-2 mg/ml), adsorption time (5-25 min), and glutaraldehyde concentration (1-4 % v/v). The optimum temperature (20-60 °C), optimum pH (3.0-10.0), kinetic parameters, thermal stability (4-70 °C), pH stability (4.0-9.0), and reusability (9 times) were investigated for characterization of immobilized lipase system. The optimum temperatures of free and immobilized lipase were 30 °C. The temperature profile of the immobilized lipase was spread over a large area. The optimum pH values for the free lipase and immobilized lipase were found to be 6.5 and 7.5, respectively. The thermal stability of immobilized lipase was evaluated, and it maintained 45 % activity at 70 °C. But, at this temperature, soluble lipase protected only 15 % activity. Also, the structural characterization of chitosan/TiO2 composite beads was analyzed with scanning electron microscope (SEM), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), and attenuated total reflection Fourier transform infrared spectroscopy analysis (ATR-FTIR). The significance of this study is improving of stability properties of lipase for the industrial usage especially production of biodiesel and dairy products.

Enhanced Stability of Α-Amylase via Immobilization onto Chitosan-Tio2 Nanocomposite

“…The Ti-O band in the range of 400-700cm -1 can be seen in case of CST nanocomposite which was ascribed to the composite formation of TiO 2 with chitosan. The peaks related to CH 2 asymmetric vibration could be seen at 2925, 2870, 1430, 1320 and 1250 cm −1 [9]. The absorption band at 1074 cm −1 represented the C-O stretching vibration of primary alcoholic group in chitosan.…”

“…The immobilized enzyme, CSTE exhibited better thermal stability since its activity decreased slower rate as the temperature increased to higher region. It preserves the tertiary structure of the enzyme and protects the enzyme from conformational changes of the active center caused at higher temperatures [9]. The thermal stability of free and immobilized α-amylase with respect to pre-incubation time was studied and the result was depicted in figure 3b.…”

“…It has many important chemical and biological properties such as biocompatibility, biodegradability bioactivity, nontoxicity and antibacterial properties [23,24]. The thermal, mechanical, chemical and physical properties of the polymer matrixes can be improved by addition of certain amount of inorganic oxides into polymer matrix [9]. In our study we have selected TiO 2 to form the nanocomposite with chitosan matrix so that the properties of the polymer can be improved.…”

Enantioselective synthesis of (S)‐naproxen using immobilized lipase on chitosan beads

“…[11][12][13][14] However, special characteristic of the industrial application for free enzymes such as good stability, activity, and selectivity under conditions far from the physiological environment is often restricted. 13,[19][20][21][22][23] A large number of research has studied the different supports for enzymatic production of a chiral drug 2,3,24-27 ; but no literature reports exist indicating chitosan beads as an enzyme carrier for synthesis of enantiomerically pure naproxen. Immobilization of the enzyme can create a heterogeneous biocatalyst that is easily recovered from the reaction mixture, reutilized, and stabilized at the reaction severe conditions.…”

Equilibrium, kinetic and thermodynamic studies of Reactive Red 120 dye adsorption by chitosan beads from aqueous solution

“…Other changes were seen at the absorbance band of 1575 cm -1 which corresponds to the interaction of (C-N) and (C-N-H). On the other hand, the C-H bond interaction due to amide II is evident at the peak of 1416 cm -1 where the peak deformed after adsorption (Deveci et al 2015). The peak at 1154 cm -1 shows antisymmetric of C-O-C stretching (Martínez et al 2004).…”