A novel method for the immobilization of a thermostable fungal chitinase and the properties of the immobilized enzyme.

The recombinant thermostable fungal chitinase of Thermomyces lanuginosus was immobilized on the phenyl Sepharose matrix, and the properties of the immobilized chitinase were studied. The immobilized enzyme was optimally active at pH 6.0 and 50 °C and showed improved activity in the acidic range of pH values when compared with the soluble enzyme. The recombinant thermostable immobilized enzyme showed remarkable thermostability at 50 °C by retaining about 45% of the activity for more than 6 H. The KM and Vmax values were 1.3 mM and 4.5 mol/min/mg of protein, respectively. Both the free and immobilized forms of the enzymes were inhibited significantly by Ag(+) but behaved similarly to various other metal ions, detergents, and additives. The immobilized enzyme was stable for at least 1 month at 4 °C.