Potato dextrose agar

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Aspergillus sp. growing in potato dextrose agar

Potato dextrose agar (BAM Media M127[1]) and potato dextrose broth are common microbiological growth media made from potato infusion and dextrose. Potato dextrose agar (abbreviated "PDA") is the most widely used medium for growing fungi and bacteria.[2]

Typical composition[edit]

value ingredients & conditions
1000 ml water
4 g (from 200 g infused potato) potatoes
(sliced washed unpeeled)
20 g dextrose
20 g agar powder
5.6±0.2 final pH
25°C temperature

Potato infusion can be made by boiling 200 grams (7.1 oz) of sliced (washed but unpeeled) potatoes in ~ 1 litre (0.22 imp gal; 0.26 US gal) distilled water for 30 minutes and then decanting or straining the broth through cheesecloth. Distilled water is added such that the total volume of the suspension is 1 litre (0.22 imp gal; 0.26 US gal). 20 grams (0.71 oz) dextrose and 20 grams (0.71 oz) agar powder is then added and the medium is sterilized by autoclaving at 15 pounds per square inch (100 kPa) for 15 minutes.[1]

A similar growth medium, potato dextrose broth (abbreviated "PDB"), is formulated identically to PDA, omitting the agar.[3] Common organisms that can be cultured on PDB are yeasts such as Candida albicans and Saccharomyces cerevisiae and molds such as Aspergillus niger.[3]

References[edit]

  1. ^ a b BAM Media M127: Potato Dextrose Agar from the U.S. Food and Drug Administration
  2. ^ Harold Eddleman, Ph. D (February 1998). "Making Bacteria Media from Potato". Indiana Biolab. disknet.com. Archived from the original on July 16, 2011. Retrieved March 4, 2011.
  3. ^ a b "Potato Dextrose Broth". Merck KGaA. Archived from the original on May 16, 2006. Retrieved May 29, 2005.

Further reading[edit]

  • Atlas, R.M.: Handbook of Microbiological Media, second edition. Lawrence C. Parks (1997)