Reuse of Brewer’s Spent Grain (BSG) for the Induction of Wickerhamomyces anomalus BS91 β-Glucosidase with Bioflavoring Potential

Glucosidases are important enzyme largely used in food industry; for this reason, different research studies have been aimed at investigating new producing microorganisms and cheap growth medium that can help to minimize their production costs and time. Food by-products and wastes are considered low-cost substrates that can play an important role from the perspective of a circular economy concept. Brewer’s spent grain (BSG) is the most abundant by-product of beer production that, thanks to its chemical and nutritional composition, has recently been re-evaluated for its application in various sectors. The aim of the present study was to induce the production of β-glucosidase in Wickerhamomyces anomalus BS91 using BSG as the main component. The results obtained during our research show that BSG is an attractive by-product of beer industry that can be used for the production of glucosidase. Enzyme activity obtained using this microorganism was equal to 369.7 ± 8.0 U/mL, six time greater than that observed in conventional nutritional medium (59.0 ± 5.7 U/mL). Also, we conducted additional research concerning β-glucosidase localization, and the obtained results show that the enzyme is tightly bound to the yeast cell wall, and this can probably greatly affect its stability since it is being protected by the cell wall itself.