β-Galactosidases (EC 3.2.1.23) constitute a large family of proteins that are known to catalyze both hydrolytic and transgalactosylation reactions. The hydrolytic activity has been applied in the food industry for decades for reducing the lactose content in milk, while the transgalactosylation activity has been used to synthesize galacto-oligosaccharides and galactose containing chemicals in re...

β -D-Galactosidases (EC 3.2.1.23) hydrolyze the terminal nonreducing β -D-galactose residues in β -D-galactosides and are ubiquitously present in all life forms including extremophiles. Eighteen microbial β -galactosidase protein sequences, six each from psychrophilic, mesophilic, and thermophilic microbes, were analyzed. Primary structure reveals alanine, glycine, serine, and arginine to be hi...

The enzyme β-galactosidases have been isolated from various sources such as bacteria, fungi, yeast, vegetables, and recombinant sources. This enzyme holds importance due to its wide applications in food industries to manufacture lactose-hydrolyzed products for lactose-intolerant people and the formation of glycosylated products. Absorption of undigested lactose in small intestine requires the a...

Three beta-galactosidase genes from Bifidobacterium bifidum DSM20215 and one beta-galactosidase gene from Bifidobacterium infantis DSM20088 were isolated and characterized. The three B. bifidum beta-galactosidases exhibited a low degree of amino acid sequence similarity to each other and to previously published beta-galactosidases classified as family 2 glycosyl hydrolases. Likewise, the B. inf...

Abstract Background Raw materials composed of easily assimilated monosaccharides have been employed as carbon source for production microbial lipids. Nevertheless, agro-industrial wastes rich in galactose-based carbohydrates not introduced feedstocks oleaginous yeasts. Results In this study, Aureobasidium namibiae A12 was found to efficiently accumulate lipid from soy molasses and whey powder c...

This work aimed at evaluating the influence of enzyme concentration, temperature, and reaction time in the lactose hydrolysis process in milk, cheese whey, and whey permeate, using two commercial β-galactosidases of microbial origins. We used Aspergillus oryzae (at temperatures of 10 and 55°C) and Kluyveromyces lactis (at temperatures of 10 and 37°C) β-galactosidases, both in 3, 6, and 9 U/mL c...

Glycoside hydrolases are organized into glycoside hydrolase families (GHFs) and within this larger group, the beta-galactosidases are members of four families: 1, 2, 35, and 42. Most genes encoding GHF 42 enzymes are from prokaryotes unlikely to encounter lactose, suggesting a different substrate for these enzymes. In search of this substrate, we analyzed genes neighboring GHF 42 genes in datab...