Identification and Characterization of a Novel α-L-Fucosidase from Enterococcus gallinarum and Its Application for Production of 2'-Fucosyllactose.

2'-fucosyllactose (2'FL) is an important nutrient in human milk that stimulates beneficial microbiota and prevents infection. α-L-fucosidase is a promising component for 2'FL synthesis. In this study, a soil-oriented α-L-fucosidase-producing strain from Enterococcus gallinarum ZS1 was isolated. Escherichia coli was employed as a host for cloning and expressing the α-L-fucosidase gene ( entfuc ). The EntFuc was predicted as a member of the GH29 family with a molecular mass of 58 kDa. The optimal pH and temperature for the activity of EntFuc were pH 7.0 and 30 °C, respectively. The enzyme exhibited a strictly specific activity for 4-Nitrophenyl-α-L-fucopyranoside (pNP-Fuc) and had a negligible effect on hydrolyzing 2'FL. EntFuc could catalyze the synthesis of 2'FL via transfucosylation action from pNP-Fuc and lactose. The yield of 2'FL reached 35% under optimal conditions. This study indicated that EntFuc with a high conversion rate is a promising enzyme source for the biosynthesis of 2'FL.