Immobilization of mannanase on sodium alginate-grafted-β-cyclodextrin: An easy and cost effective approach for the improvement of enzyme properties.

Partially purified β-mannanase was immobilized on the modified matrix of sodium alginate-grafted-β-cyclodextrin. The Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction characterization proved that β-cyclodextrin (β-CD) was successfully grafted with sodium alginate. After successful immobilization, yield of enzyme was found 91.5%, pH and temperature optima were increased, 6.0 to 7.0 and 50 °C to 55 °C respectively. Immobilized mannanase was able to reuse 15 times and retained its 70% activity, meanwhile the immobilized enzyme showed 60% activity after 30 days of storage at 4 °C. Immobilization also increased the thermostability and half-life of the enzyme when compared to the free mannanase. During the comparison of adsorption isotherm and kinetic models, Langmuir isotherm and pseudo-first order kinetics were observed to be the best fit model for the confirmation of immobilization.