Measurement of bile salt hydrolase activity from Lactobacillus acidophilusbased on disappearance of conjugated bile salts

Bile salt hydrolase activity of Lactobacillus acidophilus was measured base d on the disappearance of sodium glycocholate and sodium taurocholate from the reaction mixture using HPLC. The amount of sodium glycocholate and sodi um taurocholate that disappeared was proportional to the amount of sodium c holate that appeared in the mixture as detected by HPLC. Sodium glycocholat e did not precipitate at the enzyme reaction conditions (37 degrees C and p H 5.4) for determining bile salt hydrolase activity. The bile salt hydrolas e assay was insensitive to low oxidation-reduction potential when measuring bile salt hydrolase from L. acidophilus, an intestinal microorganism. Howe ver, EDTA and freezing temperatures were necessary to maintain stability of the partially purified enzyme during storage.