Department of Chemical Engineering, Konkuk University, 1 Hwayang-Dong, Gwangjin-gu, Seoul, 05029, Republic of Korea.
Department of Biotechnology, Hemvati Nandan Bahuguna Garhwal University (A Central University), Srinagar 246174, Uttarakhand, India.
Bioresour Technol. 2024 Sep;408:131175. doi: 10.1016/j.biortech.2024.131175. Epub 2024 Jul 29.
Upgrading biomass-derived bioethanol to higher-order alcohols using conventional biotechnological approaches is challenging. Herein, a novel, magnetic metal-organic-framework-based cofactor regeneration system was developed using ethanol dehydrogenase (EtDH:D46G), NADH oxidase (NOX), formolase (FLS:L482S), and nicotinamide adenine dinucleotide (NAD) for converting rice straw-derived bioethanol to acetoin. A magnetic zeolitic imidazolate framework-8@FeO/NAD (ZIF-8@FeO/NAD) regeneration system for cell-free cascade reactions was introduced and used to encapsulate EtDH:D46G, NOX, and FLS:L482S (ENF). ZIF-8@FeO/NADENF created an efficient microenvironment for three-step enzyme cascades. Under the optimized conditions, the yield of acetoin from 100 mM bioethanol using ZIF-8@FeO/NADENF was 90.4 %. The regeneration system showed 97.1 % thermostability at 50 °C. The free enzymes retained only 16.3 % residual conversion, compared with 91.2 % for ZIF-8@FeO/NADENF after ten cycles. The magnetic metal-organic-framework-based cofactor regeneration system is suitable for enzymatic cascade biotransformations and can be extended to other cascade systems for potential biotechnological applications.
使用传统生物技术将生物量衍生的生物乙醇升级为高碳醇具有挑战性。在此，开发了一种新型的基于磁性金属有机骨架的辅因子再生系统，该系统使用乙醇脱氢酶（EtDH:D46G）、NADH 氧化酶（NOX）、甲醛酶（FLS:L482S）和烟酰胺腺嘌呤二核苷酸（NAD）将稻草衍生的生物乙醇转化为乙酰基。引入了一种用于无细胞级联反应的磁性沸石咪唑酯骨架-8@FeO/NAD（ZIF-8@FeO/NAD）再生系统，用于封装 EtDH:D46G、NOX 和 FLS:L482S（ENF）。ZIF-8@FeO/NADENF 为三步酶级联反应创造了有效的微环境。在优化条件下，使用 ZIF-8@FeO/NADENF 从 100 mM 生物乙醇中获得的乙酰基产量为 90.4%。该再生系统在 50°C 时表现出 97.1%的热稳定性。与 ZIF-8@FeO/NADENF 相比，游离酶的残余转化率仅为 16.3%，而经过十次循环后，游离酶的残余转化率为 91.2%。基于磁性金属有机骨架的辅因子再生系统适合于酶级联生物转化，并且可以扩展到其他级联系统，以用于潜在的生物技术应用。
