Description
Use and description:
For the cultivation and enumeration of yeasts and moulds from dairy and food products. In order to suppress bacterial growth acidify the medium to pH 3.5.
Composition per litre:
Potato extract……………………………….4.0 g
Dextrose……………………………………..20.0 g
Agar……………………………………………15.0 g
Final pH of the ready to use medium: 5.6 ± 0.2
Medium preparation:
Add 39.0 grams of dehydrated culture medium to 1 litre of distilled water. Heat with repeated stirring and boil for one minute to dissolve completely. Distribute and autoclave at 121°C for 15 minutes. If desired, the pH of the medium can be adjusted to 3.5 ± 0.1 prior to pouring plates by the addition of 14 ml of sterile 10% lactic acid to melted sterile medium cooled to 45-50°C. Avoid reheating the medium after the addition of the acid.
Quality specifications:
Dehydrated medium: homogeneous, light beige fine powder.
Ready to use medium: clear to slightly hazy and pale to light yellow.
Microbiological response:
| Organism | Result |
| Aspergillus niger ATCC 16404 | Woolly and black mycelium |
| Candida albicans ATCC 10231 | Off-white creamy colonies |
Storage:
Dehydrated medium should be stored between 10 to 25°C. Once opened, place the container in a dark, dry place. The dehydrated medium should not be used if there is any lump or the colour has changed from the original.
500g wrapped pots