Actinomycete Isolation Agar with Glycerol

Actinomycetes are a group of bacteria with many features. They produce antibiotics and other therapeutically useful compounds and are very important in the cycling of organic matter in the soil ecosystem. They are also found in water and vegetation. The isolation of actinomycetes from the mixed microflora present in nature is complicated by their characteristic slow growth relative to that of other soil bacteria.

Sodium propionate is a substrate used in anaerobic fermentation. Sodium caseinate is used as a source of nitrogen. Dipotassium phosphate is used as a buffer. Asparagine is an amino acid that provides organic nitrogen. Magnesium sulfate and ferrous sulfate are ions required in a large variety of enzymatic reactions, including DNA replication. Bacteriological agar is the solidifying agent.

Preparation

Suspend 22 grams of the medium in one liter of distilled water. Mix well. Heat with frequent agitation and boil for one minute or until completely dissolved. Add 5 mL of glycerol and mix well. Distribute in appropriate containers. Sterilize in autoclave at 121 °C for 15 minutes.

Instructions for use

Inoculate and incubate at 30 ± 2 °C for 72 hours.

• Clesceri, Greenberg and Eaton (ed.). 1998. Standard methods for the examination of water and wastewater, 20th ed. American Public Health Association, Washington, D.C.
• Lechevalier. 1975. Actinomycetes of sewage-treatment plants. Environ. Protection Technol. Ser. EPA-600/2-75-031, U. S. Environmental Protection Agency, Cincinnati, Ohio.
• Lechevalier and Lechevalier. 1974. Int. J. Syst. Bacteriol. 24:278.