Composite Particles of Novozyme 435 and Silicone: Advancing Technical Applicability of Macroporous Enzyme Carriers
Composite Particles of Novozyme 435 and Silicone: Advancing Technical Applicability of Macroporous Enzyme Carriers
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Novozyme 435 和有机硅复合颗粒：提高大孔酶载体的技术适用性
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
M. Ansorge‐Schumacher
中科院分区：
文献类型：
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作者：
Lars O. Wiemann;R. Nieguth;Marrit Eckstein;M. Naumann;O. Thum;M. Ansorge‐Schumacher
酶吸附在大孔载体上的力学稳定性和浸出稳定性是影响这类生物催化剂技术适用性的一个重要问题。两者都可以从载体表面的硅酮涂层沉积中获得相当大的好处。采用扫描电镜（SEM）、透射电镜（TEM）、能谱（EDX）和BET等温线对固定化脂肪酶Novozyme 435 （NZ435）的包被进行了详细的研究，并为其稳定作用提供了解释和前提条件。硅酮在聚甲基丙烯酸甲酯（PMMA）载体上的沉积形成了互穿网络复合材料，而不是预期的核壳结构。硅酮前驱体均匀润湿载体表面，包括所有内部孔隙，并逐渐填充整个载体。同时，加入硅酮后，NZ435的表面积从初始值89 m2 - 1减小到0.2 m2 - 1。只有当硅酮浓度达到54% w/w以上时，载体外表面才会出现可见的硅酮层。最大的浸出稳定性与该层的形成相对应。机械稳定性随硅树脂沉积量的增加而增加。可以预期，硅树脂复合材料的抗浸出和/或机械应力稳定性可以很容易地转移到整个替代生物催化系统中。这将大大提高生物催化剂在化学合成中的一般技术适用性和整体实施。
The mechanical and leaching stability of enzymes adsorbed on macroporous carriers is an important issue for the technical applicability of such biocatalysts. Both can considerably benefit from the deposition of silicone coating on the carrier surface. The coating of the immobilized lipase Novozyme 435 (NZ435), as a model enzyme preparation, with different silicone loadings was studied in detail by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), as well as by energy‐dispersive X‐ray spectroscopy (EDX) and BET isotherms, and offers explanations and prerequisites for its stabilizing effects. The deposition of silicone on the poly(methyl methacrylate) (PMMA) carrier was found to form an interpenetrating network composite rather than the anticipated core‐shell structure. The silicone precursors homogeneously wet the carrier surface including all inner pores and gradually fill the complete carrier. In parallel, the surface area of NZ435 decreases from an initial value of 89 m2g−1to 0.2 m2g−1after silicone loading. A visible layer of silicone on the outer surface of the carrier was only observed at a silicone concentration of 54 % w/w and more. Maximum leaching stability corresponds to the formation of this layer. The mechanical stability increases with the amount of deposited silicone. It can be expected that stabilization against leaching and/or mechanical stress by formation of silicone composites can easily be transferred to a whole range of alternative biocatalytic systems. This should considerably advance their general technical applicability and overall implementation of biocatalysts in chemical synthesis.