Brilliant Green Bile Broth 2% is one of the most widely used medium for the detection of coliform bacteria in water, wastewater, foods, milk and dairy products. This medium is formulated as per APHA (1,2,3) for the presumptive identification and confirmation of coliform bacteria (4,5). This medium is also recommended by the ISO Committee for enumeration of coliforms by most probable number technique (6). Peptone serves as a source of essential nutrients. Lactose is the fermentable carbohydrate. Bile inhibits gram-positive bacteria whereas the gram-negative bacteria are inhibited by brilliant green. Production of gas from lactose fermentation is detected by incorporating inverted Durham's tube, which indicates the positive evidence of faecal coliform since non faecal coliforms growing in this medium do not produce gas. Further gas production in EC broth (M127) at 45deg C used as a confirmation of faecal coliform. Gram-positive spore formers may produce gas if the bile or brilliant green inhibition is weakened by reaction with food material. During examination of water samples, growth from presumptive positive tubes showing gas in Lactose Broth (M026) or Lauryl Tryptose Broth (M080) is inoculated in Brilliant Green Bile Broth 2% (M121). Gas formation within 48 ± 2 hours confirms the presumptive test (1).
Application: For Detection and Confirmation of Coliform Bacteria in Water, Waste Water, Food, Milk and Dairy Products
- Appearance: Cream to pale green homogeneous free flowing powder
- Color and Clarity of prepared medium: Emerald green colored, clear solution without any precipitate
- Cultural Response: Cultural characteristics observed after an incubation at 35-37 deg C for 18-48 hours