Fungal culture Media - Types, Ingredients, Use, Target organism
Fungal culture Media
Microbial culture media has undergone several changes since its inception with alternative nutrient sources and to cater to specific growth requirements (nutrition, pH, osmotic conditions, temperature) in the case of fastidious organisms.
Microorganisms require about 10 macro elements such as Carbon, Oxygen, Hydrogen, Nitrogen, Sulphur, Phosphorous, Potassium, Calcium, Magnesium, and Iron where the first six are used for the synthesis of Carbohydrates, Lipids, Proteins, and Nucleic acids while the remaining four is used as cations. Microelements such as Mn, Zn, Co, Mo, Ni, and Cu are used for enzymes and co-factors. Culture media also contains organic compounds as growth factors.
For fungal culture, a high carbohydrate and nitrogen source is essential with a pH range from 5 to 6 and a temperature range from 15 to 37ºC.
Types of fungal culture media
Fungal media are of two types – natural and synthetic.
Natural media is composed of natural substrates which are easy to prepare but have the disadvantage of unknown composition. Eg: Corn meal agar, Potato dextrose agar, V-8 Juice agar, Dung Agar.
Synthetic media is composed of known ingredients at specific amounts that can be duplicated with precision each time. Eg: Czapek-Dox medium, glucose-asparagine, and Neurosporacrassa minimal medium.
General purpose media such as Sabouraud dextrose agar (SDA) is nutritionally poor with acidic pH (5.6). Selective media includes Inhibitory mold agar and Dermatophyte test media.
Fungal Culture media, Ingredients, Use
Fungal culture media is composed of the following ingredients.
Fungal Culture Media | Ingredients | Target Organism / Use |
Sabouraud dextrose agar (SDA) |
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Potato dextrose agar (PDA) |
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Birdseed Agar / Niger Seed Agar / Staib Agar |
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Rice starch Agar |
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Cornmeal (tween) Agar |
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Potato Flake Agar |
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Brain-Heart Infusion (BHI) Agar |
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Mycosel/mycobiotoc Agar |
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CHROMagar Candia medium |
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Czapek-Dox Agar |
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Inhibitory Mold Agar (IMA) |
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Dermatophyte test medium (DTM) |
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Fungal Blood Culture Systems |
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Modified Leeming-Notman Agar |
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Modified Dixon Agar |
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Christensen’s Urea Agar |
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Esculin Agar |
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Trichophyton Agar (six types of media are present - Trichophyton Agar 1,2,3,4,6,7) |
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* Cycloheximide is added to reduce contamination by environmental fungi. However, it also prohibits the growth of opportunistic fungi such as Aspergillus spp., Cryptococcus neoformans, and Mucor.
* Chloramphenicol prevention of bacterial contamination. It also inhibits the growth of Actinomycetes.