Agricultural and Biosystems Engineering, North Dakota State University, Fargo, ND, USA.
Coatings and Polymeric Materials Department, North Dakota State University, Fargo, ND, USA.
Bioprocess Biosyst Eng. 2022 Aug;45(8):1311-1318. doi: 10.1007/s00449-022-02746-4. Epub 2022 Jul 25.
Magnetic nanobiocatalysts (MNBCs) are a promising immobilization approach to ease enzyme recovery during bioprocessing. However, industrial adoption of MNBCs is unfeasible because MNBC-synthesis involves complex and potentially expensive processing steps including synthesis of silica-coated superparamagnetic iron oxide nanoparticles (Si-SPIONs). We developed a single-step process for Si-SPION synthesis using a tubular electrochemical system (TES) and investigated the effect of concentration of the NaSiO coating agent on Si-SPION properties. The Si-SPIONs were used as a support for attachment of polymer-cellulase conjugate to make MNBCs. The spherical Si-SPIONs were 8-12 nm in diameter including a 2-nm silica coating. NaSiO concentration in the reactor did not affect Si-SPION morphology, but increasing NaSiO concentration reduced SPION productivity in the reactor. Protective properties of the SPION silica coatings were demonstrated by showing that they prevented dissolution of SPIONs in an acid solution for 48 h. Enzyme attachment was quantified as protein adsorption on Si-SPIONs which reached 55 μg/mg Si-SPION. The MNBCs were recovered and reused four times. The use of TES for Si-SPION synthesis is promising to reduce MNBC production complexity.
磁性纳米生物催化剂（MNBC）是一种很有前途的固定化方法，可以在生物加工过程中缓解酶的回收问题。然而，MNBC 的工业应用是不可行的，因为 MNBC 的合成涉及复杂且潜在昂贵的处理步骤，包括硅涂层超顺磁氧化铁纳米粒子（Si-SPION）的合成。我们使用管状电化学系统（TES）开发了一种用于 Si-SPION 合成的单步工艺，并研究了 NaSiO 涂层剂浓度对 Si-SPION 性能的影响。Si-SPION 被用作附着聚合物-纤维素酶缀合物的载体，以制备 MNBC。球形 Si-SPION 的直径为 8-12nm，包括 2nm 的二氧化硅涂层。反应釜中的 NaSiO 浓度不影响 Si-SPION 的形态，但增加 NaSiO 浓度会降低反应釜中 SPION 的生产率。SPION 二氧化硅涂层的保护性能通过证明它们可以防止 SPION 在酸性溶液中溶解 48 小时来证明。通过测量 Si-SPION 上的蛋白质吸附量来量化酶的附着量，达到 55μg/mg Si-SPION。MNBC 被回收并重复使用了四次。TES 用于 Si-SPION 合成具有降低 MNBC 生产复杂性的潜力。
