Mannitol is a sugar that some bacteria can use because of an enzyme that begins the breakdown of this compound. Phenol red mannitol broth is thus used to determine whether the microbe can use the sugar mannitol for carbon and energy.
Most commonly used is phenol red mannitol broth. The medium is a nutrient broth to which 0.5-1.0% mannitol is added. The p H indicator phenol red is red at neutral p H but turns yellow at p H <6.8.
Phenol Red Mannitol Broth contains pancreatic digest of casein, sodium chloride, mannitol, and phenol red. Pancreatic digest of casein provides the nutrients and growth factors necessary for growth. This media is low in carbohydrates which may interfere with the fermentation reactions of the media.
MSA also contains the sugar mannitol and the pH indicator phenol red. If an organism can ferment mannitol, an acidic byproduct is formed that will cause the phenol red in the agar to turn yellow. Most pathogenic staphylococci, such as Staphylococcus aureus , will ferment mannitol.
Phenol Red Mannitol Broth is used to study mannitol fermentation in various bacteria. Proteose peptone and beef extract serve as sources for carbon and nitrogen. Sodium chloride is the osmotic stabilizer. Phenol red is the pH indicator, which turns yellow at acidic pH i.e. on fermentation of mannitol. Gas formation is seen in Durhams tubes.
Phenol Red Maltose Broth; Phenol Red Mannitol Broth; Phenol Red Sucrose Broth; Preparation and Composition of the media Get specific Phenol Red Carbohydrate Test media from the commercial suppliers or Phenol Red Broth Base and add specific carbohydrate source based on your test requirements, or you can prepare media mixing the following ...
Phenol Red Broth is a general purpose fermentation media that includes the pH indicator Phenol Red and a series of tubes each with a different sugar. Different people use different sugars, but glucose, sucrose, lactose, and mannitol are often studied.
The differential ingredient in MSA is the sugar mannitol. Organisms capable of using mannitol as a food source will produce acidic byproducts of fermentation that will lower the pH of the media. The acidity of the media will cause the pH indicator, phenol red, to turn yellow.
Phenol Red Broth is a general-purpose differential test medium typically used to differentiate gram negative enteric bacteria. It contains peptone, phenol red (a pH indicator), a Durham tube, and one carbohydrate (glucose, lactose, or sucrose). Phenol red is a pH indicator which turns yellow below a pH of 6.8 and fuchsia above a pH of 7.4.
Phenol Red Broth is a general-purpose differential test medium typically used to differentiate gram negative enteric bacteria. It contains peptone, phenol red (a pH indicator), a Durham tube, and one carbohydrate.