Beta-galactosidase (Bifidobacterium) (B-GAL)

Beta-galactosidases in Bifidobacteria are critical enzymes responsible for the hydrolysis of lactose into glucose and galactose, enabling these beneficial commensal bacteria to utilize milk-derived sugars as a primary energy source (PMID: 30200383). These enzymes primarily belong to the glycoside hydrolase families GH2 and GH42 and are central to the bifidogenic effect, where specific carbohydrates promote the growth of Bifidobacterium species in the human gut (UniProt: B0R9M7). Beyond simple hydrolysis, these enzymes exhibit significant transgalactosylation activity, which is industrially leveraged to synthesize galacto-oligosaccharides (GOS), functional prebiotics known to enhance gut health and modulate the microbiome (PMID: 28903111). In therapeutic applications, Bifidobacterial beta-galactosidases are utilized via probiotic administration to alleviate the symptoms of lactose intolerance by providing exogenous lactase activity within the small intestine (PMID: 29425071). Furthermore, their role in breaking down complex plant-derived glycans highlights their importance in maintaining a diverse and resilient intestinal ecosystem. Research continues to explore the structural biology of these enzymes to optimize their stability and catalytic efficiency for use in functional foods and clinical nutraceuticals (PMID: 31501345).

Other names

Lactasebeta-D-galactoside galactohydrolaseExo-beta-D-galactosidaseBifidobacterial beta-galactosidase

Hydrolysis of terminal non-reducing beta-D-galactose residues in beta-D-galactosides through a double-displacement mechanism, or transgalactosylation to produce oligosaccharides when lactose concentrations are high.