Monodisperse core-shell magnetic organosilica nanoflowers with radial wrinkle for lipase immobilization
Monodisperse core-shell magnetic organosilica nanoflowers with radial wrinkle for lipase immobilization
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DOI：
10.1016/j.cej.2016.10.021
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发表时间：
2017-02-01
影响因子：
15.1
通讯作者：
Jiang, Yanjun
中科院分区：
文献类型：
--
作者：
Gao, Jing;Kong, Weixi;Jiang, Yanjun
基于Winsor III体系的双连续微乳液相，成功地合成了单分散的核壳磁性有机二氧化硅纳米花。得到的具有磁核和花状有机硅外壳的纳米花具有径向皱折、垂直沟道可调和高磁化强度(62emu/g)。将纳米花作为固定化南极假丝酵母脂肪酶B(Calb)的载体。固定化CaB的最大载量为93 mg/g(载体)，比水解度为22,700 U/g(载体)。同时，Calb@Nanoflowers表现出比游离Calb和Calb@MMPs更好的pH稳定性，在60℃的环己烷中孵育96h后，Calb@MMPs保持了65%的初始活性，在室温下放置42d，保持了90%的初始活性。此外，Calb@Nanoflowers在无溶剂体系中可以有效地催化不同链长的乙酰丙酸醇(正丁醇、正辛醇、正十二醇)酯化合成乙酰丙酸烷酯。经10次循环后，Calb@Nanoflowers催化合成乙酰丙酸丁酯的活性保持在85%以上，催化合成长链烷基乙酰丙酸酯的活性保持在96%以上，远高于商品化的N435。利用这些特性，设计具有可调皱纹通道的疏水性纳米花固定化脂肪酶开辟了一条提高脂肪酶催化活性和稳定性的新途径，并可能在各种基于脂肪酶的工业过程中有潜在的应用。(C)2016爱思唯尔B.V.保留所有权利。
The monodisperse core-shell magnetic organosilica nanoflowers were successfully synthesized by a method based on the bicontinuous microemulsion phase of the Winsor III system. The obtained nanoflowers with magnetic core and flower-like organosilica shell possess radial-wrinkle, tunable perpendicular channels, and high magnetization (62 emu/g). The nanoflowers were employed as support for Candida antarctica lipase B (CALB) covalent immobilization. The maximum amount of CALB immobilized on the nanoflowers was 93 mg/g(support), while the specific hydrolytic activity was 22,700 U/g(support). Meanwhile, the CALB@nanoflowers showed better pH stability than free CALB and CALB@MMPS, which can remain 65% of initial activity after incubated in cyclohexane at 60 degrees C for 96 h, and remain 90% of initial activity after stored in room temperature for 42 days. In addition, the CALB@nanoflowers could catalyze the synthesis of alkyl levulinates through the esterification of levulinic acid alcohols with different chain length (n-butyl alcohol, n-caprylic alcohol, n-lauryl alcohol) in a solvent-free system effectively. After recycling 10 times, the CALB@nanoflowers retained more than 85% of its initial activity in catalyzing the synthesis of butyl-levulinates and more than 96% of the initial activity in catalyzing the synthesis of long chain alkyl levulinates, which was much higher than commercial N435. With these desired characteristics, the design of hydrophobic nanoflowers with tunable wrinkle channels for lipases immobilization opens up a new way to improve the catalytic activity and stability of the lipases, and may have potential applications in various lipase-based industrial processes. (C) 2016 Elsevier B.V. All rights reserved.