Dichloran-glycerol (DG-18) agar is recommended for the enumeration of yeasts and molds that develop in products with a low water activity (aw less than 0.95). The media finds particular applications for the enumeration and isolation of xerophilic molds which may be found in dehydrated or extremely dry products, such as heavily sugared or salted foods, dried fruits, cereals, cakes and cookies, flour and meat or fish based dehydrated products. The media favors a controlled growth regarding the size and breadth of mold mycelia and yeast colonies, allowing easier and more accurate counts.
TYPICAL COMPOSITION
The composition can be adjusted in order to obtain optimal performance.
For 1 liter of complete media :
- Tryptone ...................................................................................................................... 5,0 g
- Glucose ..................................................................................................................... 10,0 g
- Monopotassium phosphate......................................................................................... 1,0 g
- Magnesium sulfate, H2O ............................................................................................. 0,5 g
- Dichloran (dichloro-2,6-nitro-4-aniline)..................................................................... 2,0 mg
- Chloramphenicol ......................................................................................................... 0,1 g
- Glycerol ................................................................................................................... 220,0 g
- Bacteriological agar................................................................................................... 13,0 g
pH of the ready-to-use media at 25 °C : 5,6 ± 0,2.
PACKAGING
Ready-to-melt medium (with glycerol):
BM10908 - 10 vials of 100 mL
Dehydrated medium (without glycerol):
BK170HA - 500 g bottle
ENUMERATION OF YEASTS & MOLDS