Enhanced catalytic activity of new acryloyl crosslinked cellulose dialdehyde-nitrilase Schiff base and its reduced form for nitrile hydrolysis.

Immobilization of enzymes to improve their catalytic properties is an attractive protocol which makes them suitable candidates to meet various industrial demands. Present study describes the synthesis of new acryloyl crosslinked cellulose dialdehyde (ACCD) for nitrilase immobilization. Nitrilase was immobilized onto ACCD via Schiff base formation i.e. imine linkages (-CH=N-). Effect of different operational parameters viz. temperature, pH and substrate concentration on the free and the immobilized nitrilases were evaluated by hydrolysis of mandelonitrile. Immobilization resulted into enhanced catalytic activity of nitrilase under different operating conditions of temperature and pH. The optimum temperature and pH for immobilized forms of nitrilase was obtained to be 55 °C and 8.0 which was higher than its free form (40 °C, 6.0). Immobilized nitrilase also exhibited good thermal and storage stability over the free form and is reusable up to sixteen repeat cycles with an appreciable retention activity.