Cloning and expression of Lactobacillus brevis β‐glucosidase and its effect on the aroma of strawberry wine

Abstract

The aim of this study was to evaluate the effect of β-glucosidase (Lb0241) derived from Lactobacillus brevis on the aroma of strawberry wine. The recombinant Lb0241 was cloned and expressed in Escherichia coli BL21 (DE3). The effect of temperature, pH, and additives on the activity of Lb0241 and its substrate specificity and kinetic parameters were analyzed. Furthermore, the effects of Lb0241 on the aroma properties of strawberry wine were evaluated by SPME-GC–MS and sensory evaluation. Lb0241 showed remarkable specificity for β-glucoside and displayed the highest activity at pH 5.0 and 30°C, with a relative activity of 55% in 12% ethanol. Ni2+ and K+ could increase the activity of Lb0241, but Fe2+, urea, 2-hydroxy-1-ethanethiol, and sodium dodecyl sulfate showed the opposite effect. Lb0241 could increase the aroma-active volatiles of esters, terpenoids, and phenols, and decrease alcohols and volatile acids. Overall, Lb0241 showed promising prospects in terms of aroma release in strawberry wine. Practical applications A notable part of non-volatile glycosidic precursors present in fruit wine constitutes a reserve of potential aroma-active molecules. Thus, the hydrolysis of aromatic precursors could significantly enhance the aroma of fruit wine. Our results showed that the new β-glucosidase Lb0241, which was derived from Lactobacillus brevis T61, exhibited strong acid and ethanol resistance. Moreover, Lb0241 could effectively hydrolyze aromatic precursors and enhance the level of aroma compounds in strawberry wine. Therefore, Lb0241 has potential application prospects and economic value to improve the flavor of fruit wine.