MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China.
College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou 310027, China.
Molecules. 2018 Jan 11;23(1):144. doi: 10.3390/molecules23010144.
Enzymatic membrane bioreactors (EMBRs), with synergistic catalysis-separation performance, have increasingly been used for practical applications. Generally, the membrane properties, particularly the pore structures and interface interactions, have a significant impact on the catalytic efficiency of the EMBR. Therefore, a biomimetic interface based on a phospholipid assembled onto a polysulfone hollow-fiber membrane with perfect radial gradient pores (RGM-PSF) has been prepared in this work to construct a highly efficient and stable EMBR. On account of the special pore structure of the RGM-PSF with the apertures decreasing gradually from the inner side to the outer side, the enzyme molecules could be evenly distributed on the three-dimensional skeleton of the membrane. In addition, the supported phospholipid layer in the membrane, prepared by physical adsorption, was used for the immobilization of the enzymes, which provides sufficient linkage to prevent the enzymes from leaching but also accommodates as many enzyme molecules as possible to retain high bioactivity. The properties of the EMBR were studied by using lipase from for the hydrolysis of glycerol triacetate as a model. Energy-dispersive X-ray and circular dichroism spectroscopy were employed to observe the effect of lecithin on the membrane and structure changes in the enzyme, respectively. The operational conditions were investigated to optimize the performance of the EMBR by testing substrate concentrations from 0.05 to 0.25 M, membrane fluxes from 25.5 to 350.0 L·m·h, and temperatures from 15 to 55 °C. As a result, the obtained EMBR showed a desirable performance with 42% improved enzymatic activity and 78% improved catalytic efficiency relative to the unmodified membrane.
酶膜生物反应器（EMBRs）具有协同催化-分离性能，越来越多地被用于实际应用。通常，膜的性质，特别是孔径结构和界面相互作用，对 EMBR 的催化效率有重大影响。因此，本工作制备了基于磷脂组装在具有完美径向梯度孔（RGM-PSF）的聚砜中空纤维膜上的仿生界面，以构建高效稳定的 EMBR。由于 RGM-PSF 的特殊孔径结构，孔径从内侧到外侧逐渐减小，酶分子可以均匀分布在膜的三维骨架上。此外，通过物理吸附在膜中制备的负载磷脂层用于酶的固定化，这提供了足够的连接以防止酶浸出，但也容纳尽可能多的酶分子以保持高生物活性。通过使用脂肪酶从 进行甘油三乙酸酯的水解来研究 EMBR 的性质，作为模型。能量色散 X 射线和圆二色性光谱分别用于观察卵磷脂对膜的影响和酶的结构变化。通过测试从 0.05 到 0.25 M 的底物浓度、从 25.5 到 350.0 L·m·h 的膜通量以及从 15 到 55°C 的温度，研究了操作条件以优化 EMBR 的性能。结果，与未改性膜相比，所获得的 EMBR 表现出理想的性能，酶活性提高了 42%，催化效率提高了 78%。
