β-Galactosidase: Insights into source variability, genetic engineering, immobilisation and diverse applications in food, industry and medicine

Abstract

β-Galactosidases are crucial enzymes that hydrolyse oligosaccharides and polysaccharides with terminal β-1,4-glycosidic bonds. Though the traditional application of β-Galactosidases has been to catalyse the breakdown of lactose in dairy products, its application extends beyond the production of lactose-free products since variants capable of facilitating lactose condensation and exhibiting galactosyl transferase activity are extensively utilised for the synthesis of prebiotic galacto-oligosaccharides. This review analyses β-Galactosidase in multiple aspects, including sources, classification, characterisation, immobilisation, genetic engineering and applications in terms of whey treatment, biofuel production, production of lactose-free dietary product, synthesis of galacto-oligosaccharides and the early detection of cellular senescence and tumours.