Hydrolysis of conjugated bile acids by cell-free extracts from aerobic bacteria

By means of an aerobic enrichment culture technique, several bacteria that hydrolyze conjugated bile acids and modify the formed deconjugates were isolated from feces of man, rat, and chicken and from soil. Hydrolase activity was intracellular and extractable, and the yield of the enzymes was increased by adding the conjugated bile acids to the culture media. The hydrolase from bacterium of human origin was stable, having a pH optimum at about 7.0. All bile acid conjugates were hydrolyzed linearly as a function of time.