| Summary: | 碩士 === 元智大學 === 化學工程與材料科學學系 === 100 === Compared with the conventional adsorption chromatography, the expanded bed adsorption (EBA) technology offers the advantages of combining the unit operations of particulate removal, product concentration and product capture into one single step in protein recovery. Biomolecules can be recovered directly from fermentation broth.
The cellulose, stainless steel powder and Fe3O4 nano magnetic powder were employed for custom-make adsorbent through the water-in-oil suspension thermal regeneration method in the present study. The results of physical characterizations of the magnetic particles showed the wet densities in the values between 1.12 to 1.31 g mL-1 and the size distribution is in the range of 150 to 300 μm. The water content is from 57 % to 74 %, and the specific surface area is around 1.4~2.3 m2 mL-1. The liquid mixing performances in the expanded bed were studied through residence time distribution (RTD) test, which showed that flow velocity was an important parameter effecting on the stability of expanded bed. Using RTD analysis indicate the best characterizations of fludisation is M10 under the magnetism. However, the opration flow velocity (500 cm h-1) is 2-folds higher than STREAMLINE Base and M10 without magnetism (250 cm h-1) at identical expansion ratio.
The structure and morphology of magnetic particles were characterized using optical photomicrographs, scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FT-IR). The optical photomicrographs indicated that the spherical magnetic particles were dispersed uniformly. The SEM micrograph shows that the magnetic particles have a porous surface structure. Infrared spectroscopy depicted characteristics of absorption bands for magnetic particles (O–H, C=C, C–O–C and Fe–O bonds).
The STREAMLINE Base and M10 were subsequently immobilized with dye-ligand and played as affinity adsorbent to bind bovine serum albumin (BSA) and lysozyme in isothermal adsorption and different chromatography mode. In addition, thermodynamics and adsorption kinetics were determined. From the result when raised the temperature (298 K to 308 K) that increased the effect of adsorption capacity. The dynamic adsorption of BSA protein in EBA with Streanline Base and M10 were investigated at identical expansion ratio.
The maximum adsorption capacity and optimal adsorption temperature of BSA protein for STREAMLINE Base and M10 were 35.48 mg g-1 at 313 K and 18.04 mg g-1 at 308 K, respectively. The maximum adsorption capacity and optimal temperature for adsorption of lysozyme on M10 resin was 17.28 mg g-1 at 308 K. The Kd values decreased when adsorbed BSA/lysozyme increased for either STREAMLINE Base or M10 resins between 298K and 318K. The negative values of Gibbs free energy were observed which demonstrated BSA protein and lysozyme adsorption system for STREAMLINE Base and M10 were spontaneous reaction.
Finally, the dynamic adsorption capacity of BSA using M10 adsorbent at EBA with external magnetism has higher 10% yield and 5% recovery than STREAMLINE Base and M10 without magnetism. The results demonstrated that M10 is a competitive adsorbent for recovery of biomolecules under expanded bed operation.
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