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University of Sulaimani School of Science Biology Department. Practical Mycology 3 rd Class Lab. 2 : 19 .10. 2014. Culture Media for Fungi. A microbiological medium ( media, plural) is the food that we use for culturing bacteria, molds, and other microorganisms. Definition.
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University of Sulaimani School of Science Biology Department Practical Mycology 3rdClass Lab. 2 : 19 .10. 2014 Culture Media for Fungi
A microbiological medium (media, plural) is the food that we use for culturing bacteria, molds, and other microorganisms. Definition
Media may be either liquid (Broth) , solid or semisolid (gel) media. • The growth requirements for fungi may vary from strain to strain, thus media generally contain source of Carbon, Nitrogenand Vitamins. • Glucose(dextrose) is the most widely utilizable. Fructose and mannoseare the next and are found in media from natural sources. Sucrosemay be used in some media. Culture Media for Fungi
Nitrogen sources include peptone, yeast extract, malt extract, amino acids, ammoniumandnitrate compounds. • Salts, including Fe,Znand Mn are often added to "defined" media, but are usually not added to the common media used for routine culture. • Fungi have natural deficiencies for vitamins that are satisfied at a small concentrations. The most common naturally occurring vitamin deficiencies are thiaminand biotin.
Media will affect colony morphologyand color, whether particularstructures are formed or not. • And may affect whether the fungus will even grow in culture, for example, some fungi lack the necessary enzymes to utilize different carbon sources. • All fungi require several specific elements for growth and reproduction.
In general there are two types of media: • Defined media where all its components are known. • Adefinedmedia where most components are unknown (Natural media).
1- Potato Dextrose Agar (PDA): It is a general purpose media for isolation of fungi and molds. But this can be too rich, encouraging the mold sporulation and pigment production in some dermatophytes. Components: - Potatoes 200g - Agar 15-20g - Dextrose 15g - Distilled Water 1000ml Some types of media use in culturing fungi
Procedure: 1- Clean potato and cut into small pieces without peeling. 2- Cook potatoes for 1 hour in a steamer or 40 minutes in an autoclave in 500ml of distilled water. 3- Filter the mixture through muslin. 4- At the same time melt the agar in 500 ml of distilled water. 5- Mix the potato extract with agar then add 15g of dextrose and stir until dissolve. 6- Make up the mixture to 1 liter. 7- Divide the mixture into two 500ml bottles. 8- Autoclave at 15 pound and 121Cfor 15-20 minutes. 9- Allow medium to cool to 55-60, then pour into sterilized plates.
2- Corn Meal Agar (CMA): Use for growing a wide range of fungi, particularly members of the imperfect fungi and wood inhabiting fungi. Provides a good balance of mycelium growth and sporulation because has less easily digestible carbohydrate. Components: - Agar 15-20g - Corn - Meal 20g - Distilled Water 1000ml
Procedure: 1- Heat 500ml of water to 70C, then add corn-meal and maintain at 60C(do not exceed 60C) for 1 hour. 2- Filter the mixture through muslin and use only the filtrate. 3- At the same time melt the agar in 500 ml of distilled water. 4- Mix the corn-meal extract and agar thoroughly. 5- Make up the mixture to 1 liter. 6- Divide the mixture into two 500ml bottles. 7- Autoclave at 15 pound and 121Cfor 15-20 minutes. 8- Allow medium to cool to 55-60, then pour into sterilized plates.
3- Water Agar (WA): Cellulose destroying fungi and spoilage fungi retain their ability to produce cellulasewhen grown on a weak medium such as water agar with a piece of sterile paper. • Components: - Agar 20g - Distilled Water 1000ml Procedure: 1- Melt the agar in the water. 2- Divide the mixture into two 500ml bottles. 3- Autoclave at 15 pound and 121Cfor 15-20 minutes. 4- Allow medium to cool to 55-60, then pour into sterilized plates.
4- Malt Extract Agar (MEA): Malt Extract Agar is also frequently used for culturing fungi from soilandwoods. Lacks peptone, and is useful for culturing many Ascomycota, where sporulation in some species is inhibited by peptone. • Components: - Malt Extract 20g - Agar 20g - Glucose 20g - Distilled Water 1000ml - Sucrose 200g (for MEA + Sucrose).
5- Sabouraud Dextrose Agar (SAB): It is the standard medium for recovery and maintenance of a wide variety of fungi commonly isolated in the clinical laboratory. Components: - Glucose 20g - Peptone 10g - Agar 20g - Distilled Water 1000ml
6- Czapek-Dox Agar (CZ): It is a media used for the isolation and culturing of saprophytic soil microorganisms. • Components: - Sucrose 30g - Sodium Nitrate (NaNO3) 3g - Magnesium Sulphate (MgSO4.7H2O) 0.5g - Potassium Chloride (KCL) 0.5g - Iron Sulphate (FeSO4.7H2O) 0.1g - DipotassiumHydrogen Phosphate (KH2PO4) 1g - Agar 20g - Distilled Water 1000ml
Procedure: 1- Suspend 55.1g of components in 1 liter of distilled water. 2- Divide the mixture into two 500ml bottles. 3- Autoclave at 15 pound and 121 Cfor 15-20 minutes. 4- Allow medium to cool to 55-60, then pour into sterilized plates.
7-Yeast Extract Agar (YEA):????? Homework
Next lab. Isolation of Fungi
Benson H. J. (2002). Microbiological Applications : Laboratory Manual in General Microbiology.8th ed.Boston McGraw Hill, Reference:
