EC Broth with Durham tube is used in the detection of fecal coliform bacteria as an indication of fecal pollution of food and water from sources other than potable water.
- Digest of casein provides nitrogen source
- Bile salts inhibit fecal streptococci and sporeformers
- Phosphate buffer maintains pH of the medium
- Sodium chloride maintains the osmotic equilibrium
Gas produced during lactose fermentation at an incubation temperature of 35 ± 2°C indicates the presence of coliform bacteria. Gas production at the elevated temperatures indicates the presence of fecal coliforms, usually E. coli. Growth (turbidity) at the elevated temperatures without gas production indicates a source other than the feces of warmblooded animals. A Durham tube collects the gas produced during lactose fermentation.