Formation of Oligosaccharides During Hydrolysis of Lactose in Milk Using β‐Galactosidase from Bacillus circulans

The characteristics of β‐galactosidase from Bacillus circulans , and its suitability for hydrolysis of milk lactose were compared with those of Escherichia coli and Kluyveromyces lactis enzymes. Enzyme activity of β‐galactosidase from B. circulans was not affected by major cations and proteins present in skim milk, whereas milk proteins and sodium and calcium ions decreased the activity of the enzymes from E. coli and K. lactis. The enzyme from B. circulans produced less oligosaccharides than E. coli and K. lactis during hydrolysis of lactose in skim milk at different lactose concentrations. Oligosaccharides produced by the enzyme from B. circulans disappeared almost completely at the latter stage of hydrolysis, while a large amount of oligosaccharides were still detected even at 98% conversion of lactose with enzymes from E. coli and K. lactis.