Potato Dextrose Agar is the media used to grow fungus and is widely used in antifungal activity. Colony on PDA (Potato Dextrose Agar) & PCA (Potato Carrot Agar) are profuse, black, and hairy. PDA media is a selective growth medium. The short form of Potato dextrose agar is PDA media. Because of its high sugar content and acidic pH, Potato Dextrose Agar is a selective medium for fungus. The potato peptone promotes the growth of aerial mycelium and pigment synthesis, particularly in Fusarium, Aspergillus, and Penicillium species.
PDA media
A potato dextrose agar (PDA) is a popular microbiological culture medium which is made from potato infusion and dextrose. It is the most popular growth media for fungus and bacteria that attack living plants or organic plant matter that is degrading.
Principle of PDA media
The agent that solidifies is agar. To lower the pH to 3.5 and limit the development of germs, a specified percentage of sterile tartaric acid can be applied.
How to prepare PDA media from PDA powder?
For preparing PDA media from PDA powder, we have a three simple and easy steps:
- About 39 g of PDA powder is dissolved in 1 L of distilled water.
- They are properly mixed and dissolve to make the solution clear.
- Finally for 15 minutes the solution is autoclaved at 121 degree.
- At last , after autoclave, the media is poured in petri dishes about 25 mL in each dish.
PDA media composition
The composition of PDA media are listed in Table 1.
| Particulars | Amounts |
| Potato infusion | 200 g |
| Dextrose | 20 g |
| Agar | 20 g |
| Distilled water | 1 L |
PDA media preparation
Potato infusion is made by simmering 200 g of sliced, unpeeled potatoes in 1 liter of distilled water for 30 minutes. Potato infusion is saved after being filtered via cheesecloth (or you may buy it already dehydrated). Add the other ingredients and simmer until dissolved and is autoclaved for 15 minutes at 121 °C . About 20 to 25 cc at a time into sterile 15 mm by 100 mm Petri dishes. pH final: 5.6 + 0.2.
PDA media for fungi
For the study of antifungal activity of bacterial isolated, PDA media is widely used. Generally agar well diffusion method is used to study of antifungal activity of extracts. The whole process was already explained in our previous contents.
Uses of PDA media
- In clinical samples, PDA is used to isolate and count yeasts and molds. On PDA medium, stock cultures of certain dermatophytes may be kept alive. PDA is also used to promote sporulation and distinguish between typical dermatophyte kinds based on the production of certain pigments.
- PDA can cultivate a range of bacteria and fungi that are present in soil. This agar can be used to stop the development of bacteria and fungi when combined with antibiotics or acid. In the food business, PDA is used to check for fungus that might taint food items. Additionally, it is utilized in the pharmaceutical sector to check for possible antifungal ingredients in drugs.
References
http://Bacteriological Analytical Manual, 8th Edition, Revision A, 1998.
