Klinglers iron agar medium is used to find the enterobacteria which can ferment glucose , lactose and hydrogen Sulphide . They are H₂S producing bacteria .
This media have phenol red as an indicator. When the glucose is fermented to acid , the production of acid turn the indicator from red to yellow, but it is then reoxidised and turns red again . When lactose is fermented it produce large amount of acid , and turn indicator yellow . Hence the slant will become yellow.And combination of ferrous sulphate and sodium thiosulphate helps in detection of H₂S which produce black color at the butt .
