Immobilization of Inulinase on Aminated Multiwalled Carbon Nanotubes by Glutaraldehyde Cross-Linking for the Production of Fructose

In the present work, an attempt was made to enhance immobilization yield and operational stability of inulinase (Exo-II) from Penicillium oxalicum onto amino (+NH2) terminated multiwalled carbon nanotubes (MWCNTs) through glutaraldehyde (GA) cross-linking. A statistical study using response surface methodology (RSM) was employed to optimise inulinase immobilization onto 3-aminopropyl-triethoxysilane (APTES) and GA modified surfaces of MWCNTs. Under optimized conditions (APTES concentration 4%; sonication time 4h; GA concentration 2%; GA activation time 75min; enzyme load 27.5IU and enzyme coupling time 2.75h), inulinase activity and immobilization yield obtained were 73.9% and 84.9%, respectively. An increase in inulinase activity (1.22-fold) and immobilization yield (1.14-fold) was observed after modification of aminated MWCNTs by GA cross-linking. Developed immobilized biocatalyst shown excellent operational stability for 43 cycles for fructose production in a batch system. Increased immobilization yield and operational stability of the developed biocatalyst onto APTES-GA functionalized MWCNTs justifies it a good candidate for fructose production from inulin. [GRAPHICS] .