Electrospun polyacrylonitrile nanofibrous membranes for chitosanase immobilization and its application in selective production of chitooligosaccharides

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.

Figure optionsDownload as PowerPoint slideHighlights
► A novel microbial source of chitosanase was isolated from soil.
► Crude chitosanase was covalently immobilized on a novel nanomatrix.
► Immobilization of chitosanase enzyme immensely improved reusability and storage stability of enzyme.
► Hydrolysis of different chitosan substrates was achieved.
► Selective production of glucosamine and chitooligosaccharides were done by changing the reaction temperatures.