Vakili Fatemeh, Mojtabavi Somayeh, Imanparast Somaye, Kianmehr Zahra, Forootanfar Hamid, Faramarzi Mohammad Ali
Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tehran University of Medical Sciences, P.O. Box 14155-6451, 1417614411 Tehran, Iran.
Department of Cellular and Molecular Biology (Biochemistry), Faculty of Biological Science, North Tehran Branch, Islamic Azad University, P.O. Box 165115-3311, 77009847 Tehran, Iran.
3 Biotech. 2020 Oct;10(10):447. doi: 10.1007/s13205-020-02437-5. Epub 2020 Sep 23.
The present study was designed to propose a simple, cost-effective, and efficient method for the preparation of a biocompatible composite made from magnetic diatomaceous earth (mDE) coated by aminopropyltriethoxysilane (APTES) and its application for immobilization of porcine pancreatic lipase (PPL). The produced mDE-APTES was instrumentally characterized and the obtained results of FTIR analysis and scanning electron microscopy equipped by energy-dispersive X-ray spectroscopy (SEM-EDS) showed successful coating of APTES on mDE surface. PPL was then immobilized onto mDE to obtain the biocatalyst of PPL@mDE (immobilization yield and efficiency of 78.0 ± 0.3% and 80.1 ± 0.6, respectively) and the presence of enzyme was confirmed by EDS method. The attained results of the reusability of PPL@mDE revealed that 57% of the initial activity was retained after 11 cycles of biocatalyst application. PPL@mDE demonstrated higher storage stability than the free enzyme at 4 °C, 25 °C, and 37 °C. The apparent (2.35 ± 0.12 mM) and (13.01 ± 0.64 µmol/min) values for the immobilized enzyme were considerably altered compared to those of the free enzyme ( > 0.05). PPL@mDE was subsequently employed for the synthesis of banana flavor (isoamyl acetate) in -hexane, which yields an esterification percentage of 100 at 37 °C after 3 h. However, it merits further investigations to find out about large-scale application of the as-synthesized biocatalyst for esterification.
本研究旨在提出一种简单、经济高效的方法，用于制备由氨丙基三乙氧基硅烷（APTES）包覆的磁性硅藻土（mDE）制成的生物相容性复合材料，并将其应用于固定化猪胰脂肪酶（PPL）。对制备的mDE-APTES进行了仪器表征，傅里叶变换红外光谱（FTIR）分析以及配备能量色散X射线光谱仪的扫描电子显微镜（SEM-EDS）获得的结果表明，APTES成功包覆在mDE表面。然后将PPL固定在mDE上，以获得PPL@mDE生物催化剂（固定化产率和效率分别为78.0±0.3%和80.1±0.6），并通过EDS方法确认了酶的存在。PPL@mDE的重复使用性结果表明，在生物催化剂应用11个循环后，保留了57%的初始活性。PPL@mDE在4°C、25°C和37°C下表现出比游离酶更高的储存稳定性。与游离酶相比，固定化酶的表观 值（2.35±0.12 mM）和 值（13.01±0.64 μmol/min）有显著变化（P>0.05）。随后，PPL@mDE用于在正己烷中合成香蕉风味剂（乙酸异戊酯），在37°C下反应3小时后，酯化率达到100%。然而，关于合成的生物催化剂在酯化反应中的大规模应用还有待进一步研究。
