Certain embodiments of the disclosure are directed to modified Bacillus spp. host cells expressing/producing β-galactosidase and/or lactase enzymes and the use of such enzymes for the production of galactooligosaccharide (GOS) compositions in one or more dairy related end products. More particularly, certain embodiments are directed to expressing/producing such β-galactosidase and/or lactase enzymes in modified Bacillus spp. host cells, wherein such enzymes produced and purified from the modified Bacillus host cells are free of unwanted/undesirable enzymatic side activities including, but not limited to, unwanted/undesirable lipase side activities, phospholipase side activities, side activities, cellulase side activities, pectinase side activities, amylase side activities, protease side activities, mannanase side activities and the like.
