National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Lihu Road No. 1800, Binhu District, Wuxi, 214122, Jiangsu, People's Republic of China.
Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Lihu Road No. 1800, Binhu District, Wuxi, 214122, Jiangsu, People's Republic of China.
World J Microbiol Biotechnol. 2022 Jun 24;38(8):144. doi: 10.1007/s11274-022-03330-4.
D-allulose is a rare low-calorie sugar that has many fundamental biological functions. D-allulose 3-epimerase from Agrobacterium tumefaciens (AT-DAEase) catalyzes the conversion of D-fructose to D-allulose. The enzyme has attracted considerable attention because of its mild catalytic properties. However, the bioconversion efficiency and reusability of AT-DAEase limit its industrial application. Magnetic metal-organic frameworks (MOFs) have uniform pore sizes and large surface areas and can facilitate mass transport and enhance the capacity for enzyme immobilization. Here, we successfully encapsulated cobalt-type AT-DAEase into the cobalt-based magnetic MOF ZIF-67@FeO using a self-assembly strategy. We confirmed the immobilization of enzyme AT-DAEase and characterized the enzymatic properties of the MOF-immobilized AT-DAEase@ZIF-67@FeO. The AT-DAEase@ZIF-67@FeO nanoparticles had higher catalytic activity (65.1 U mg) and bioconversion ratio (38.1%) than the free AT-DAEase. The optimal conditions for maximum enzyme activity of the AT-DAEase@ZIF-67@FeO nanoparticles were 55 °C and pH 8.0, which were significantly higher than those of the free AT-DAEase (50 °C and pH 7.5). The AT-DAEase@ZIF-67@FeO nanoparticles displayed significantly improved thermal stability and excellent recycling performance, with 80% retention of enzyme activity at a temperature range of 45-70 °C and > 45% of its initial activity after eight cycles of enzyme use. The AT-DAEase@ZIF-67@FeO nanoparticles have great potential for large-scale industrial preparation of D-allulose by immobilizing cobalt-type AT-DAEase into magnetic MOF ZIF-67@FeO.
D-阿洛酮糖是一种罕见的低热量糖，具有许多基本的生物学功能。根瘤农杆菌（Agrobacterium tumefaciens）中的 D-阿洛酮糖 3-差向异构酶（AT-DAEase）催化 D-果糖转化为 D-阿洛酮糖。由于其温和的催化特性，该酶引起了相当大的关注。然而，AT-DAEase 的生物转化效率和可重复使用性限制了其工业应用。磁性金属-有机骨架（MOFs）具有均匀的孔径和较大的表面积，可促进质量传递并增强酶固定化的能力。在这里，我们成功地使用自组装策略将钴型 AT-DAEase 封装到钴基磁性 MOF ZIF-67@FeO 中。我们证实了酶 AT-DAEase 的固定化，并对固定化酶 AT-DAEase@ZIF-67@FeO 的酶学性质进行了表征。AT-DAEase@ZIF-67@FeO 纳米颗粒具有比游离 AT-DAEase 更高的催化活性（65.1 U mg）和生物转化率（38.1%）。AT-DAEase@ZIF-67@FeO 纳米颗粒的最大酶活性的最佳条件为 55°C 和 pH 8.0，明显高于游离 AT-DAEase（50°C 和 pH 7.5）。AT-DAEase@ZIF-67@FeO 纳米颗粒表现出显著提高的热稳定性和优异的回收性能，在 45-70°C 的温度范围内保留了 80%的酶活性，并且在使用八次后仍保持初始活性的 45%以上。通过将钴型 AT-DAEase 固定到磁性 MOF ZIF-67@FeO 中，AT-DAEase@ZIF-67@FeO 纳米颗粒为大规模工业制备 D-阿洛酮糖提供了巨大潜力。
