NADH Oxidation in a Microreactor with an Oscillating Magnetic Field
NADH Oxidation in a Microreactor with an Oscillating Magnetic Field
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DOI：
10.1556/1846.2015.00034
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发表时间：
2016-01
影响因子：
2.7
通讯作者：
Anita Šalić;Katarina Pindrić;G. H. Podrepšek;N. Novosel;M. Leitgeb;B. Zelić
中科院分区：
文献类型：
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作者：
Anita Šalić;Katarina Pindrić;G. H. Podrepšek;N. Novosel;M. Leitgeb;B. Zelić
在本研究中，合成并表征了磁赤铁矿（γ-Fe2O3）的磁性纳米颗粒（MNP）。采用多因素实验设计和进化操作（EVOP）方法优化了乙醇脱氢酶（ADH）在MNPs上的固定化。确定了固定化过程的最佳操作条件（γADH = 0.08 mg/mL，2%戊二醛进行表面活化，t = 28 h），在此条件下，实现了 S.A. = 118 ± 6 U/mg 的比活性和 η = 84.97 ± 3.67% 的固定化效率。与天然酶相比，固定在 MNP 上的 ADH 保留了初始活性的 66.45 ± 3.66%。在最佳条件下固定在 MNP 上的 ADH 用作模型反应——NADH 氧化的生物催化剂。 NADH 氧化在两种不同的磁性微反应器配置中进行：(1) 配备永久方形磁铁的微反应器和 (2) 配备电磁体和振荡磁场的微反应器，使磁性颗粒能够在微反应器中运动。在具有振荡磁场的系统中，在缩短 2 倍的停留时间内实现了相等的转化率 (X = 100%)。
In this study, magnetic nanoparticles (MNPs) of maghemite (γ-Fe2O3) were synthesized and characterized. The method of multifactor experimental design and evolutionary operation (EVOP) was used to optimize immobilization of the alcohol dehydrogenase (ADH) enzyme on MNPs. Optimal operating conditions for the immobilization process were determined (γADH = 0.08 mg/mL, 2% glutaraldehyde for surface activation, t = 28 h), and in such conditions, a specific activity of S.A. = 118 ± 6 U/mg and immobilization efficiency of η = 84.97 ± 3.67% were achieved. Compared to the native enzyme, ADH immobilized on MNPs retained 66.45 ± 3.66% of the initial activity. ADH immobilized on MNPs at optimal conditions was used as a biocatalyst for model reaction—NADH oxidation. NADH oxidation was performed in two different magnetic microreactor configurations: (1) microreactor equipped with permanent square magnets and (2) microreactor equipped with an electromagnet and an oscillating magnetic field that enables magnetic particles movement in the microreactor. In the system with the oscillating magnetic field, equal conversion (X = 100%) was achieved in 2-fold shorter residence time.