Description
Bismuth Sulfite Agar: The Optimal Medium for Isolating Salmonella spp.
Bismuth Sulfite Agar is an essential tool for microbiologists aiming to isolate Salmonella spp., particularly Salmonella Typhi, from food and clinical specimens. This highly selective medium effectively inhibits the growth of competing bacteria while promoting the robust development of Salmonella.
Approximate Formula
Ingredients per Liter:
- Peptic Digest of Animal Tissue: 10.0 g
- Beef Extract: 5.0 g
- Ferrous Sulfate: 0.3 g
- Bismuth Sulfite Indicator: 8.0 g
- Disodium Hydrogen Phosphate: 4.0 g
- Dextrose: 5.0 g
- Brilliant Green: 0.025 g
- Agar: 20.0 g
Final pH: 7.5 ± 0.2 at 25℃
Key Features and Preparation
The combination of peptic digest and beef extract provides essential nutrients, while dextrose serves as a vital energy source. Disodium hydrogen phosphate acts as a buffering agent, ensuring optimal pH conditions. The bismuth sulfite indicator and brilliant green work together to suppress gram-positive bacteria and coliforms, allowing Salmonella to thrive.
To prepare Bismuth Sulfite Agar, suspend 52.0 g of the powder in 1 L of purified water. Heat with frequent agitation until fully dissolved—do not autoclave!
Appearance and Storage
The dehydrated medium appears as a free-flowing off-white powder, transforming into a light grey-green gel once prepared. Store the medium tightly capped in its original container at 5-30°C for optimal performance. The dehydrated medium has a shelf life of three years, while prepared media should be stored out of direct light at 2-8°C.
Quality Control
For quality assurance, inoculate and incubate at 36 ± 1℃ for 40-48 hours to confirm the medium’s efficacy in isolating Salmonella spp.
In summary, Bismuth Sulfite Agar is a valuable asset in laboratories focused on isolating Salmonella, ensuring reliable results with its selective properties and straightforward preparation process.
Visit our [Food Hygiene Detection Series] for more related products.
Reviews
There are no reviews yet.