Brilliant Green Bile Broth 2%
BGBB contains two inhibitors of both gram-positive and selected gram-negative organisms, namely, oxgall and brilliant green dye. Fermentation is detected by gas production.
EC Broth contains casein peptone as a source of nutrients. Lactose provides the carbohydrate fermented by coliform bacteria and Escherichia coli. In addition, lactose-positive bacteria metabolize lactose with gas formation. Gram-positive bacteria are inhibited by the mixture of bile salts.
EC Broth with MUG
The presence of the fluorescence using a long-wave UV light source confirms the presence of Escherichia coli and no further confirmation is required. MUG detects anaerogenic strains, which may not be detected in the conventional procedure. Lactose is a source of energy. Casein peptone provides additional nutrients. The mixture of bile salts is inhibiting for gram-positive bacteria, particularly bacilli and fecal streptococci. The substrate 4-methylumbelliferyl-b-D-glucuronide is hydrolyzed by an enzyme, b-glucuronidase, possessed by most Escherichia coli and a few strains of Salmonella, Shigella and Yersinia, to produce a fluorescent end product, 4-methylumbelliferone.
Lauryl Sulfate or Lauryl Tryptose Broth
This media was developed for the detection of coliform organisms by the American Public Health Association (APHA). It is now the standard medium of choice in the presumptive phase of the standard coliform MPN test for the microbiological examination of water.