Background: β-Glucosidases catalyze the hydrolysis of cellobiose and cellodextrins, releasing glucose as the main
product. This enzyme is used in the food, pharmaceutical, and biofuel industries. The aim of this work is to
improve the β-glucosidase production by the fungus
Lichtheimia ramosa
by solid-state fermentation (SSF)
using various agroindustrial residues and to evaluate the catalytic properties of this enzyme.
Results: A high production of β-glucosidase, about 274 U/g of dry substrate (or 27.4 U/mL), was obtained by
cultivating the fungus on wheat bran with 65% of initial substrate moisture, at 96 h of incubation at 35°C. The
enzymatic extract also exhibited carboxymethylcellulase (CMCase), xylanase, and β-xylosidase activities. The
optimal activity of β-glucosidase was observed at pH 5.5 and 65°C and was stable over a pH range of 3.5–10.5.
The enzyme maintained its activity (about 98% residual activity) after 1 h at 55°C. The enzyme was subject to
reversible competitive inhibition with glucose and showed high catalytic activity in solutions containing up to
10% of ethanol.
Conclusions: β-Glucosidase characteristics associated with its ability to hydrolyze cellobiose, underscore the
utility of this enzyme in diverse industrial processes.
