Bacillus cereus Agar (PEMBA)

//Bacillus cereus Agar (PEMBA)

Bacillus cereus Agar (PEMBA)

SKU: KM0186 Category:

Bacillus cereus agar (PEMBA) is used for the selective isolation and enumeration of Bacillus cereus in food samples. It is said to be particularly suitable for the detection of small numbers of Bacillus cereus particularly in the presence of other contaminating organisms. Bacillus cereus agar (PEMBA) is based on the formulation developed by Holbrook and Anderson.

The peptone provides the required carbon, nitrogen and vitamins. Mannitol is a fermentable carbohydrate. Bromothymol blue is a pH indicator used to detect mannitol fermentation. Sodium chloride maintains the osmotic balance. Magnesium sulphate provides divalent cations and sulphate. Di-sodium hydrogen phosphate and potassium dihydrogen phosphate are buffering agents. Egg yolk emulsion (BM0140) must be added to this media to assess lecithinase production. Sodium pyruvate is present to improve egg yolk precipitation and enhance B. cereus sporulation. The medium is made selective by the inclusion of polymyxin B sulphate (LS1051).

Additional Information

Shelf Life (days)

Storage Temp (°C)

Dehydrated Medium Appearance

Prepared Medium Appearance

Dehydrated Medium Colour

Prepared Medium Colour

Dehydrated PH

Prepared PH

Product Description

Organisms Ref. No Result
Bacillus cereus NCTC 10320 Growth, blue colonies with precipitation halo
Bacillus subtilis NCTC 10400 Growth, white/yellow colonies without precipitation halo
Escherichia coli NCTC 12241 Inhibited

 

Formula*

g/L
Peptone 1.0
Mannitol 10.0
Magnesium sulphate 0.1
Sodium chloride 2.0
Di-sodium hydrogen phosphate 2.5
Potassium dihydrogen phosphate 0.25
Bromothymole blue 0.12
Sodium pyruvate 10.0
Agar 15.0
Total 41.0
*Adjusted/supplemented as required to meet performance requirements

Preparation

Suspend 41.0g of the medium in 950ml of deionised / purified water. Allow the medium to soak whilst mixing for 10 minutes.

Heat with frequent agitation and boil for one minute to completely dissolve the medium. Sterilise at 121°C for 15 minute and cool to 45- 50°C. Aseptically add 50ml egg yolk emulsion (BM0140) and the appropriate number of vials of Bacillus Cereus Selective Supplement (PEMBA) (LS1051). Mix well and dispense into appropriate sterile containers.