Mannitol salt agar
Mannitol saline agar plate with colonies of Micrococcus sp. (1), Staphylococcus epidermidis (2) and S. aureus (3)
Mannitol salt agar (also Chapman agar) is a selective medium for the isolation of pathogenic staphylococci and micrococci . This nutrient medium is mainly used in food analysis and microbiological examinations in hospitals.
The high saline content of the medium prevents most other bacteria from growing. Phenol red and meat extract cause the slightly reddish color at a neutral pH value. If a bacterium growing on it is able to utilize mannitol as a carbon source, the surrounding medium takes on a yellowish color due to the drop in pH (acid formation). The utilization of mannitol is an indication of the pathogenicity of the examined bacterium. The investigation of its lipase activity can provide further information about the pathogenicity .
composition
- Pancreas hydrolyzate from casein 5.0 g / l
- Animal tissue peptone 5.0 g / l
- Beef meat extract 1.0 g / l
- Sodium chloride (table salt) 75.0 g / l
- D- mannitol 10.0 g / l
- Phenol red 0.025 g / l
- Agar 15.0 g / l
- pH 7.4
See also
Individual evidence
- ↑ Product information from Carl Roth
- ↑ Product information Mannitol-NaCl-Phenol-Red-Agar from Merck , accessed on February 27, 2017.
- ↑ Acumedia product data sheet ( PDF; 89 kB).