Gao Min, Li Xiaoyuan, Qi Danping, Lin Jiangli
Key Laboratory of Oil and Gas Fine Chemicals, Ministry of Education & Xinjiang Uyghur Autonomous Region, College of Chemistry, Xinjiang University, Urumqi, Xinjiang 830046, China.
Key Laboratory of Oil and Gas Fine Chemicals, Ministry of Education & Xinjiang Uyghur Autonomous Region, School of Chemical Engineering and Technology, Xinjiang University, Urumqi, Xinjiang 830046, China.
ACS Omega. 2020 Dec 11;5(50):32706-32714. doi: 10.1021/acsomega.0c05078. eCollection 2020 Dec 22.
Pectinase is widely used in juice production, food processes, and other fields. However, owing to poor stability, free pectinase is difficult to separate from a substrate after hydrolysis and cannot be reused, and thus its industrial use is limited. Immobilized pectinase can solve these problems well. We prepared a carrier material of immobilized enzyme, which is called porous spherical reduced graphene oxide (rGO) with a rich pore structure, large specific surface area, strong hardness, and good biocompatibility to enzyme. Then, we evaluated the performance of the porous spherical rGO immobilized pectinase and characterized its structure by IR, XRD, and SEM. Using this material as a carrier of immobilized enzyme improves the load and catalytic activity of the enzyme. After 10 times of continuous use, the porous spherical rGO immobilized enzyme still maintained its initial relative enzyme activity at around 87%, indicating that immobilized pectinase had a stronger cycling stability, and its thermal stability, acid-base tolerance, and storage stability were superior to those of free pectinase. The results were compared with those of other studies on immobilized pectinase. The relative activity of pectinase immobilized by porous spherical rGO was at a high level after 10 consecutive uses. Overall, the spherical rGO is an excellent immobilized enzyme carrier material.
果胶酶广泛应用于果汁生产、食品加工等领域。然而，由于稳定性较差，游离果胶酶在水解后难以从底物中分离出来，无法重复使用，因此其工业应用受到限制。固定化果胶酶能够很好地解决这些问题。我们制备了一种固定化酶的载体材料，即具有丰富孔结构、大比表面积、高硬度和良好酶生物相容性的多孔球形还原氧化石墨烯（rGO）。然后，我们评估了多孔球形rGO固定化果胶酶的性能，并通过红外光谱（IR）、X射线衍射（XRD）和扫描电子显微镜（SEM）对其结构进行了表征。使用这种材料作为固定化酶的载体提高了酶的负载量和催化活性。连续使用10次后，多孔球形rGO固定化酶仍保持其初始相对酶活性在87%左右，表明固定化果胶酶具有更强的循环稳定性，其热稳定性、酸碱耐受性和储存稳定性均优于游离果胶酶。将结果与其他关于固定化果胶酶的研究进行了比较。多孔球形rGO固定化的果胶酶在连续使用10次后相对活性处于较高水平。总体而言，球形rGO是一种优异的固定化酶载体材料。
