Chemistry and Sources of Lactase Enzyme with an Emphasis on Microbial Biotransformation in Milk

The milk of mammals contains a disaccharide called lactose, which is often commonly referred to as milk sugar. Lactose does not have an overwhelming sweetness, has weak solubility, and cannot be absorbed straight from the gastrointestinal system. Lactase is an enzyme that breaks down lactose into glucose and galactose. Glucose and galactose have a sweetness that is comparable to that of sucrose, but they are three to four times more soluble and are more readily absorbed by the colon. Lactase, which may also be referred to as 3‐galactosidase or β‐glycosidases, can be found in the intestines of newborn animals as well as in the cells of some microbes (although lactase activity often decreases after weaning). The vast majority of the lactic lactococci that are utilized in the production of cheese have lactase activity. Glycosidases are enzymes that hydrolyze glycosides into oligosaccharides, polysaccharides, and glycoconjugates in a way that is efficient and inexpensive. Lactase is an enzyme that can be found in higher plants, animals, and even microbes. It is a member of the β‐glycosidases family. Utilizing β‐galactosidases allows for the degradation of lactose in milk, which results in the production of lactose‐free milk that is sweeter than ordinary milk and is ideal for persons who are lactose intolerant. The lactose‐degrading enzyme known as β‐galactosidase is used in the food industry to produce dairy products that are easier to digest, sweeter, more soluble, and have a more flavorful profile. Enzymes called β‐galactosidase are put to use in the food processing industry so that a variety of products, including hydrolyzed milk products, whey, and galactooligosaccharides, can be manufactured. As a consequence of this, the enzyme in discussion is an important protein that can be manufactured by recombinant technology. This chapter covers the origins of β‐galactosidase, as well as its structure, recombinant synthesis, and the key alterations that have been made to the enzyme in order to improve its efficiency.