Bile acid induction specificity of 7 alpha-dehydroxylase activity in an intestinal Eubacterium species

Steroids. 1980 Jan;35(1):103-9. doi: 10.1016/0039-128x(80)90115-4.


The addition of cholic acid to growing cultures of Eubacterium species V.P.I. 12708 caused a 25 and 46-fold increase in 7 alpha-dehydroxylation activity using cell extracts or whole cell suspensions, respectively. Bile acid conversion rates using either [14C]-cholic acid or [14C]-chenodeoxycholic acid as substrates increased at approximately the same rate when either cholic or chenodeoxycholic acid was added to growing cultures as inducer. The induction of 7 alpha-dehydroxylase activity was highly specific requiring a free C-24-carboxyl group and an unhindered 7 alpha-hydroxy group on the B ring of the steroid nucleus. Unexpectedly, cholic acid also rapidly induced NADH:flavin oxidoreductase activity in growing cultures of this bacterium.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bile Acids and Salts / metabolism
  • Bile Acids and Salts / pharmacology*
  • Cholic Acids / pharmacology*
  • Colonic Neoplasms / microbiology
  • Enzyme Induction
  • Eubacterium / drug effects
  • Eubacterium / enzymology*
  • Feces / microbiology
  • Humans
  • Hydroxysteroid Dehydrogenases*
  • Kinetics
  • Oxidoreductases*
  • Steroid Hydroxylases / metabolism*
  • Structure-Activity Relationship


  • Bile Acids and Salts
  • Cholic Acids
  • Oxidoreductases
  • Hydroxysteroid Dehydrogenases
  • 7 alpha-hydroxysteroid dehydrogenase
  • Steroid Hydroxylases