Bile salts

Bile salt is an organic sodium salt with a conjugate of any of the bile acids along with either glycine or taurine. Biles salts are composed of four different kinds of bile acids – cholic, deoxycholic, chenodeoxycholic and lithocholic acids.
Bile salts are extracted under controlled conditions from purified fresh bile, to be used in bacteriological culture media, where it behaves as a selective inhibitory agent that enables isolation and identification of pathogens. For example, in MacConkey Agar/Broth.

Bile salts may be used as one of the selective agents to prevent the growth of injured Escherichia coli cells, in an experiment done in order to identify the specific agent in the selective media which would inhibit the growth of the injured Escherichia coli ML30 cells. It may also be used for identification of isolates of Vibrio (Beneckea) vulnificus which is a halophilic bacterium, found responsible for causing several human infections.

Bile salts are surface-active steroid compounds and their primary physiological function is to aid in the digestion of lipophilic nutrients in intestinal tracts of vertebrates.