β-Galactosidase from Aspergillus oryzae

β-Galactosidase is a member of the glycoside hydrolase clan A (GH-A) family. It is widely present in microorganisms, which includes both prokaryotes and eukaryotes.

β-Galactosidase from Aspergillus oryzae has been used:

• in in vitro nuclear magnet resonance (NMR)
• as a standard in the β-galactosidase assay to determine the concentration of cell-associated β-galactosidase
• to modify sugar residues on the surface of the mutant slime cells to study the adhesive properties
• for enzymatic hydrolysis of lactose
• for reversed-phase (RP) adsorption
• in the hydrolysis of whey lactose

β-Galactosidase acts on the terminal β-D-galactosyl moieties of disaccharides, glycoconjugates, and polysaccharides. It is useful in mediating transglycosylation reactions such as the synthesis of galactooligosaccharides (GOS). β-Galactosidases might be used for glycobiological and biotechnological applications.

β-galactosidase cleaves lactose into its monosaccharide components, glucose and galactose. It also catalyses the transglycosylation of glucose into allolactose, the inducer of β-galactosidase, in a feedback loop.

One unit will hydrolyze 1.0 μmole of lactose per minute at pH at 4.5 at 30 °C.