Improvement in the Thermostability of a Recombinant β-Glucosidase Immobilized in Zeolite under Different Conditions

Abstract

β-Glucosidase is part of the cellulases and is responsible for degrading cellobiose into glucose, a compound that can be used to produce biofuels. However, the use of the free enzyme makes the process more expensive. Enzyme immobilization improves catalytic characteristics and supports, such as zeolites, which have physical-chemical characteristics and ion exchange capacity that have a promising application in the biotechnological industry. This research aimed to immobilize by adsorption a recombinant β-glucosidase from Trichoderma reesei, obtained in Escherichia coli BL21 (DE3), in a commercial zeolite. A Box Behnken statistical design was applied to find the optimal immobilization parameters, the stability against pH and temperature was determined, and the immobilized enzyme was characterized by SEM. The highest enzymatic activity was determined with 100 mg of zeolite at 35 °C and 175 min. Compared to the free enzyme, the immobilized recombinant β-glucosidase presented greater activity from pH 2 to 4 and greater thermostability. The kinetic parameters were calculated, and a lower KM value was obtained for the immobilized enzyme compared to the free enzyme. The obtained immobilization parameters by a simple adsorption method and the significant operational stability indicate promising applications in different fields.

Enhancing the ethanol production by exploiting a novel metagenomic-derived bifunctional xylanase/β-glucosidase enzyme with improved β-glucosidase activity by a nanocellulose carrier

“…Additionally, compared with β-glucosidase activity of PersiBGLXyn1, the β-glucosidase immobilized on alginate–chitin and chitosan–chitin supports retained near 20% of its initial activity after 8 repeated use ( Romo-Sánchez et al, 2014 ). In another work, recombinant β-glucosidase immobilized in Zeolite demonstrated less than 20% activity after 6 cycles ( Ramírez-Ramírez et al, 2022 ). The obtained results indicated the effectiveness of PersiBGLXyn1 immobilization for improving its reusability and applications in different fields.…”