PEPTONE IRON AGAR

The ability of certain bacterial species to liberate sulfur from sulfur-containing amino acids or other compounds in the form of hydrogen sulphide is an important characteristic for their identification. Hydrogen sulphide production can be detected by incorporating a sulfur source and an H2S indicator system in the medium. Peptone Iron Agar which is modification of Levin`s original formula is used to detect H2S production by organisms. This medium utilizes sodium thiosulphate, an inorganic compound as a supplemental source of sulfur and ferric ammonium citrate as the H2S indicator in the medium. Peptone Iron Agar scores over Lead Acetate Agar, a medium to detect H2S, in giving clear and early results. This is because ferric ammonium citrate is a better indicator of hydrogen sulphide, as compared to lead acetate.

for detection of hydrogen sulphide production by microorganisms