KM0078 – Dichloran Rose Bengal Chloramphenicol Agar

//KM0078 – Dichloran Rose Bengal Chloramphenicol Agar

KM0078 – Dichloran Rose Bengal Chloramphenicol Agar

Dichloran Rose Bengal Chloramphenicol (DRBC) agar is based on the formulation described by King et al. and is used for the selective isolation and enumeration of yeasts and moulds from food samples.

The peptone provides the required carbon, nitrogen and vitamins. Glucose is a fermentable carbohydrate. Potassium di-hydrogen phosphate is a buffering agent and magnesium sulfate is a source of divalent ions and sulfate. In order to curtail the size of the colony diameters of spreading fungi, the antifungal agent dichloran is added to the base and the pH is reduced to 5.6. Rose Bengal suppresses growth of bacteria and restricts the size and height of colonies of more rapidly growing molds. The inclusion of chloramphenicol ensures the suppression of bacteria present in environmental and food samples. Rose Bengal is absorbed by yeast and mold colonies and this further aids in their enumeration.

Occasionally reduced recovery of yeasts may be encountered due to the increased activity of Rose Bengal at pH 5.6.

SKU: KM0078 Category:

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
Aspergillus brasiliensis NCPF 2275 Growth, white mycelium with black spores
Mucor racemosus DSMZ 5226 Growth, white mycelium with black spores
Candida albicans NCPF 3179 Growth, white colonies (with pink hue)
Saccharomyces cerevisiae NCPF 3178 Growth, white colonies (with pink hue)
Bacillus subtilis NCTC 10400 Inhibited
Escherichia coli NCTC 12241 Inhibited

 

Formula*

g/L
Peptone 5.0
Glucose 10.0
Potassium di-hydrogen phosphate 1.0
Magnesium sulphate 0.5
Dichloran 0.002
Rose Bengal 0.025
Agar 15.0
Chloramphenicol 0.1
Total 31.6
*Adjusted/supplemented as required to meet performance requirements

Preparation

Suspend 31.6g of the medium and 220g of glycerol in one litre of deionised / purified water. Allow the medium to soak whilst mixing for 10 minutes. Sterilise at 121°C for 15 minutes with frequent stirring to completely dissolve the medium. Cool to 45-50°C and aseptically dispense into appropriate sterile containers.

Protracted boiling or prolonged holding at elevated temperature induces precipitation.