Beta-galactosidase (β-gal or LacZ (for the E. coli gene/protein))

Beta-galactosidase is an enzyme that catalyzes the hydrolysis of terminal non-reducing β-D-galactose residues from β-D-galactosides such as lactose, producing glucose and galactose—key steps in carbohydrate metabolism across many organisms including bacteria (*E. coli*), fungi, plants, and animals[1][7]. In *E. coli*, it also converts some lactose into allolactose, which acts as an inducer molecule regulating expression of genes involved in lactose uptake and metabolism through the lac operon system—a foundational model for understanding gene regulation mechanisms[3]. Deficiency leads to conditions like lactose intolerance; severe inherited deficiencies can cause more serious metabolic disorders such as galactosialidosis or Morquio syndrome B[5]. In biotechnology, beta-gal serves extensively both as a reporter gene product ("blue/white screening") due to its ability to cleave artificial substrates like X-GAL yielding colored products,[6] and industrially for production of prebiotic oligosaccharides using microbial enzymes with high specificity toward various glycosyl linkages.[2]

Other names

Beta-galβ-GalLactase (in some contexts)LacZ (gene/protein from E. coli)EC 3.2.1.23

For supplements: Enzymatic hydrolysis—exogenous beta-galactosidase breaks down dietary lactose into absorbable monosaccharides. For research/biotechnology applications: Cleavage of chromogenic substrates such as X-Gal to produce detectable products for reporter assays