Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, Hauz Khas, New Delhi, India.
Bioresour Technol. 2012 Jul;115:152-7. doi: 10.1016/j.biortech.2011.11.101. Epub 2011 Dec 2.
Polyacrylonitrile nanofibrous membranes (PANNFM) were prepared by electrospinning from 10 wt.% of PAN solution and its surface was modified by amidination reaction. A new chitosan degrading enzyme from Aspergillus sp. was covalently immobilized on PANNFM. Immobilization efficiency of 80% was achieved by activating PANNFM surface for 30 min followed by 2 h treatment with enzyme solution. The optimum temperature and pH for immobilized enzyme were 50°C and 5.8, respectively. The immobilized chitosanase retained >70% activity after ten repeated batch reaction and could be stored up to 60 days at 4°C with minor loss in activity. Chitosan hydrolysis using different substrates were studied using immobilized chitosanase in batch conditions. Continuous selective production of chitooligosaccharides (dimer to hexamer) by changing the temperature was achieved by PANNFM-chitosanase.
聚丙烯腈纳米纤维膜（PANNFM）通过静电纺丝从 10wt.%的 PAN 溶液中制备，其表面通过酰胺化反应进行修饰。从曲霉属中获得了一种新型壳聚糖降解酶，并将其共价固定在 PANNFM 上。通过将 PANNFM 表面活化 30 分钟，然后用酶溶液处理 2 小时，实现了 80%的固定化效率。固定化酶的最适温度和 pH 值分别为 50°C 和 5.8。固定化壳聚糖酶在十次重复批反应后保留了>70%的活性，并且在 4°C 下储存 60 天，活性损失较小。在分批条件下使用固定化壳聚糖酶研究了不同底物的壳聚糖水解。通过 PANNFM-壳聚糖酶，可以通过改变温度连续选择性生产低聚壳聚糖（二聚体到六聚体）。
