Influence of manganese on the activity and production of a β-D-glucosidase associated to the biomass of a thermophilic strain of Bacillus licheniformis

ABDULHAMID MARIA BELEN; BAIGORI, MARIO DOMINGO; PERA, LICIA MARIA

Cordoba

Congreso; XI Congreso Argentino de Microbiología General- SAMIGE; 2015

SOCIEDAD ARGENTINA DE MICROBIOLOGIA GENERAL

β-Glucosidases (EC 3.2.1.21) constitute a group of well-studied hydrolases. The principal reaction catalyzed is the hydrolytic cleavage of β-glycosidic linkages. They have been described in a variety of fungi and bacteria and the physiologic roles are extremely diverse: glucoside ceramide catabolism in human tissue; cell wall, pigment, and cyanoglucoside metabolism in plants; and the utilization of oligosaccharide substrates by many fungi and bacteria. The interest in this enzyme centres on its roles in the enzymatic hydrolysis of cellulose. The rate and extent of cellulose hydrolisys can be increased by supplementing commercial cellulases with immobilized β-D-Glucosidase, which has high stability and can be recovered and reused. Furthermore, for the industrial saccharification of cellulosic materials, β-glucosidases from thermophilic bacteria are of particular interest due to their increased stability and activity. On the other hand, certain authors have reported that some divalent cations may increase the activity of this enzyme.In this work, we detect a β-D-Glucosidase activity, associated to biomass of Bacillus licheniformis, using p-nitrophenyl-L-β-glucopyranoside as substrate. We tested the effect of different salts on the enzymatic activity, resulting MnCl2 which present positive effect on the activity, reaching values of about 18 U/L. In addition, this cation was selected to study its influence on the production of the enzyme, adding different amounts to the culture medium showing that the final concentration of 0.3 mM increased the enzymatic production by about 20%. These results could be of relevance to the bioethanol industry in which lignocellulosic material is used as feedstock for fermentation.This work was supported by grants PICT 2011?2158 (FONCyT), PIUNT E548/3 (UNT) and PIP 339 (CONICET).