title: Transformation of bile acids by Clostridium perfringens.
abstract: Thirty-five strains of Clostridium perfringens were examined for their ability to transform bile acids, both in growing cultures and by washed whole cells. All of the strains oxidized the 3 alpha-hydroxy group to an oxo group, and all except three converted the same alpha-hydroxy group into a beta-configuration. The oxidative 3 alpha-dehydrogenation was barely detectable under anaerobic cultural conditions but was clearly demonstrated in an aerated system using washed whole cells, with a pH optimum between 7.0 and 9.0. The epimerizing reaction amounting to 10 to 20% conversion was observed in anaerobic cultures and also with resting cells, irrespective of oxygen supply. Both reactions were carried out with seven conventional 3 alpha-hydroxy bile acids, thus producing a series of 3-oxo and 3 beta-hydroxy derivatives that could be examined for gas-liquid chromatographic and mass spectrometric behavior. No evidence for the occurrence of 7 alpha- and 12 alpha-hydroxysteroid dehydrogenase activities among the test strains was found. A highly potent deconjugating hydrolase was elaborated by all of the strains.
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D001647:Bile Acids and Salts / Q000378:metabolism*; D001711:Biotransformation; D055598:Chemical Phenomena; D002621:Chemistry; D002635:Chenodeoxycholic Acid / Q000378:metabolism*; D002793:Cholic Acids / Q000378:metabolism*; D003016:Clostridium perfringens / Q000378:metabolism*; D003840:Deoxycholic Acid / Q000031:analogs & derivatives*; D006002:Glycodeoxycholic Acid / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration
chemical_list: D001647:Bile Acids and Salts; D002793:Cholic Acids; D003840:Deoxycholic Acid; D002635:Chenodeoxycholic Acid; D006002:Glycodeoxycholic Acid