Kinetics of improved production and thermostability of an intracellular β-glucosidase from a mutant-derivative of Cellulomonas biazotea

Abstract

The highest productivity (20 IU l⁻¹ h⁻¹) of β-glucosidase by a mutant of Cellulomonas biazotea was 2.5-fold more than that of the parent organism. The enzyme had a lower activation energy (57 kJ mol⁻¹) than the native enzyme (68 kJ mol⁻¹). The enzyme from the mutant had enthalpy and entropy values for irreversible intactivation of 95.6 kJ mol⁻¹ and 60 J.mol⁻¹ K⁻¹ compared with 108 kJ mol⁻¹ and 86 J mol⁻¹ K⁻¹ for the native enzyme suggesting that the mutation had stabilized the enzyme.