HOME

TheInfoList



OR:

Potato dextrose agar (BAM Media M127
from the U.S.
Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food s ...
) and potato dextrose broth are common microbiological
growth media A growth medium or culture medium is a solid, liquid, or semi-solid designed to support the growth of a population of microorganisms or cells via the process of cell proliferation or small plants like the moss ''Physcomitrella patens''. Different ...
made from
potato The potato is a starchy food, a tuber of the plant ''Solanum tuberosum'' and is a root vegetable native to the Americas. The plant is a perennial in the nightshade family Solanaceae. Wild potato species can be found from the southern United S ...
infusion Infusion is the process of extracting chemical compounds or flavors from plant material in a solvent such as water, oil or alcohol, by allowing the material to remain suspended in the solvent over time (a process often called steeping). An inf ...
and
dextrose Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, using ...
. Potato dextrose agar (abbreviated "PDA") is the most widely used medium for growing fungi and bacteria.


Typical composition

: Potato infusion can be made by boiling of sliced (washed but unpeeled) potatoes in ~ distilled water for 30 minutes and then decanting or straining the broth through
cheesecloth Cheesecloth is a loose-woven gauze-like carded cotton cloth used primarily in cheesemaking and cooking. Grades Cheesecloth is available in at least seven different grades, from open to extra-fine weave. Grades are distinguished by the numb ...
.
Distilled water Distilled water is water that has been boiled into vapor and condensed back into liquid in a separate container. Impurities in the original water that do not boil below or near the boiling point of water remain in the original container. Thus, dis ...
is added such that the total volume of the suspension is . dextrose and agar powder is then added and the medium is sterilized by
autoclaving An autoclave is a machine used to carry out industrial and scientific processes requiring elevated temperature and pressure in relation to ambient pressure and/or temperature. Autoclaves are used before surgical procedures to perform sterilizat ...
at for 15 minutes. A similar growth medium, potato dextrose broth (abbreviated "PDB"), is formulated identically to PDA, omitting the
agar Agar ( or ), or agar-agar, is a jelly-like substance consisting of polysaccharides obtained from the cell walls of some species of red algae, primarily from ogonori ('' Gracilaria'') and "tengusa" ('' Gelidiaceae''). As found in nature, agar ...
. Common organisms that can be cultured on PDB are yeasts such as ''
Candida albicans ''Candida albicans'' is an opportunistic pathogenic yeast that is a common member of the human gut flora. It can also survive outside the human body. It is detected in the gastrointestinal tract and mouth in 40–60% of healthy adults. It is usu ...
'' and ''
Saccharomyces cerevisiae ''Saccharomyces cerevisiae'' () (brewer's yeast or baker's yeast) is a species of yeast (single-celled fungus microorganisms). The species has been instrumental in winemaking, baking, and brewing since ancient times. It is believed to have been ...
'' and molds such as ''
Aspergillus niger ''Aspergillus niger'' is a mold classified within the ''Nigri'' section of the ''Aspergillus'' genus. The ''Aspergillus'' genus consists of common molds found throughout the environment within soil and water, on vegetation, in fecal matter, on de ...
''.


References


Further reading

* Atlas, R.M.: ''Handbook of Microbiological Media'', second edition. Lawrence C. Parks (1997) Microbiological media Potatoes {{Microbiology-stub