کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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73558 | 49064 | 2013 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Immobilization of invertase on silica monoliths with hierarchical pore structure to obtain continuous flow enzymatic microreactors of high performance Immobilization of invertase on silica monoliths with hierarchical pore structure to obtain continuous flow enzymatic microreactors of high performance](/preview/png/73558.png)
Monolithic silica rods of 4 mm diameter and 2–5 cm length, exhibiting very open and uniform 3D hierarchical pore structure of 35 μm flow-through macropores and ca. 20 nm mesopores were synthesized using the sol–gel processing combined with pore templating and phase separation. These monoliths were successfully converted into miniaturized multichannel continuous-flow reactors which (for a single rod) could operate at flow rates up to about 20 mL/min at backpressure not exceeding 2.5 bar. After covalent attachment of invertase, considered as a model enzyme, their potentials were tested in reaction of sucrose hydrolysis and the results were compared, using Michaelis–Menten kinetics, with the performance of mesoporous cellular foam (MCF)-bound invertase immobilized in the same way. The hydrolysis of sucrose appeared to proceed with maximum velocity over 1000 times faster in the monolithic bioreactor than in MCF-based slurry system, and invertase embedded in the mesopores of silica monoliths showed notably larger affinity (lower KM) to substrate than the native enzyme. The reactors stored at 4 °C retained initial activity for at least 6 week and no change in the microreactor performance was seen for at least 2 week of continuous operation.
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► Silica monoliths with very open and uniform bi-modal pore structure were prepared.
► Monoliths were successfully converted into continuous micro-bioreactors.
► A single rod microreactor could operate at flow rates up to 20 mL/min at <2.5 bar.
► Invertase embedded in silica matrix was exceptionally active in sucrose hydrolysis.
► Micro-bioreactors properties remained stable for at least two weeks of operation.
Journal: Microporous and Mesoporous Materials - Volume 170, April 2013, Pages 75–82