Biomaterial Database

Influence of bile on beta-galactosidase activity of component species of yogurt starter cultures. 1994

D O Noh, and S E Gilliland

Department of Animal Science, Oklahoma State University, Stillwater 74078.

The influence of bile on beta-galactosidase activity and the cellular integrity of Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus salivarius ssp. thermophilus were tested. Two strains (OS 1 and OS 2) of L. delbrueckii ssp. bulgaricus and three strains (HC 15, 17, and 18) of S. salivarius ssp. thermophilus were studied. In the presence of .15% oxgall, beta-galactosidase activity of whole cells of both species was significantly increased. However, at a higher concentration (.3% oxgall), the beta-galactosidase activity was significantly less than in the presence of .15% oxgall. The presence of oxgall did not promote the cell lysis of any of the strains of either species. Additionally, the presence of oxgall did not cause the leakage of the enzyme from the cells. Thus, the presence of oxgall increased the cellular permeability to allow more substrate to enter the cells, thereby increasing beta-galactosidase activity, and, at higher concentrations, was inhibitory to beta-galactosidase activity of both species.

UI	MeSH Term	Description	Entries
D007778	Lactobacillus	A genus of gram-positive, microaerophilic, rod-shaped bacteria occurring widely in nature. Its species are also part of the many normal flora of the mouth, intestinal tract, and vagina of many mammals, including humans. Lactobacillus species are homofermentative and ferment a broad spectrum of carbohydrates often host-adapted but do not ferment PENTOSES. Most members were previously assigned to the Lactobacillus delbrueckii group. Pathogenicity from this genus is rare.
D002463	Cell Membrane Permeability	A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.	Permeability, Cell Membrane
D001616	beta-Galactosidase	A group of enzymes that catalyzes the hydrolysis of terminal, non-reducing beta-D-galactose residues in beta-galactosides. Deficiency of beta-Galactosidase A1 may cause GANGLIOSIDOSIS, GM1.	Lactases,Dairyaid,Lactaid,Lactogest,Lactrase,beta-D-Galactosidase,beta-Galactosidase A1,beta-Galactosidase A2,beta-Galactosidase A3,beta-Galactosidases,lac Z Protein,Protein, lac Z,beta D Galactosidase,beta Galactosidase,beta Galactosidase A1,beta Galactosidase A2,beta Galactosidase A3,beta Galactosidases
D001646	Bile	An emulsifying agent produced in the LIVER and secreted into the DUODENUM. Its composition includes BILE ACIDS AND SALTS; CHOLESTEROL; and ELECTROLYTES. It aids DIGESTION of fats in the duodenum.	Biliary Sludge,Sludge, Biliary
D013291	Streptococcus	A genus of gram-positive, coccoid bacteria whose organisms occur in pairs or chains. No endospores are produced. Many species exist as commensals or parasites on man or animals with some being highly pathogenic. A few species are saprophytes and occur in the natural environment.
D015014	Yogurt	A slightly acid milk food produced by fermentation due to the combined action of Lactobacillus acidophilus and Streptococcus thermophilus.	Yoghurt