In this study, we immobilized polygalacturonase by sol-gel entrapment for the continuous preparation of pectic oligosaccharides (POS) from mango peel wastes and evaluated their antibacterial activity. We characterized the immobilized polygalacturonase by scanning electron microscopy, thermo gravimetric analyzer, fourier transform infrared spectrometer and raman spectrum. Results showed that the polygalacturonase was successfully immobilized by the sol-gel encapsulation, which retained as much as 94.6% of its initial activity. The immobilized enzyme exhibited enhanced pH tolerance and thermal stability compared with its free counterpart. For example, the immobilized enzyme retained 57% of relative activity at 55 °C for 2 h, whereas the free enzyme retained only 17% of relative activity. Moreover, the immobilized enzyme showed good recyclability, which retained 65% of its initial activity after 6 batch reactions. Furthermore, we examined the antibacterial activities of POS prepared by the immobilized polygalacturonase hydrolysis by typical bacteria. The POS was mainly polygalacturonic acid formed by →1)-α-GalpA-(4→ and possessed the best antibacterial activity with a polymerization degree of 2–4. Therefore, we found it could be used as a natural antibacterial agent in food industry. These results suggested that immobilized polygalacturonase was efficient in terms of its high catalytic activity and stability, and it can be applied to continuous POS production.

在这项研究中，我们通过溶胶-凝胶法固定化了聚半乳糖醛酸酶，用于从芒果皮废物中连续制备果胶寡糖（POS），并评估了其抗菌活性。我们通过扫描电子显微镜，热重分析仪，傅立叶变换红外光谱仪和拉曼光谱对固定化的半乳糖醛酸酶进行了表征。结果表明，聚半乳糖醛酸酶通过溶胶-凝胶封装成功地固定化，保留了其最初活性的94.6％之多。与游离酶相比，固定化酶表现出更高的pH耐受性和热稳定性。例如，固定化酶在55°C下保持2小时相对活性的57％，而游离酶仅保留相对活性的17％。此外，固定化酶显示出良好的可回收性，经过6批反应后，保留了其初始活性的65％。此外，我们研究了固定化半乳糖醛酸酶被典型细菌水解制备的POS的抗菌活性。POS主要是由→1）-α-GalpA-（4→）形成的聚半乳糖醛酸，具有最佳的抗菌活性，聚合度为2-4，因此可以作为食品工业中的天然抗菌剂。这些结果表明固定化的聚半乳糖醛酸酶就其高催化活性和稳定性而言是有效的，并且可以用于连续的POS生产。