Isolation of Actinomycetes from Soil ____________________________________  1.) Obtain a soil sample      -Soil type:        a) Dry - richest in actinomycetes.        b) Neutral to alkaline      - Sandy soil favors: Streptomyces     - Organic rich soil favors : Microminospora  2.) Create a suspension by mixing 1g of soil with 99 mls of      sterile ddH2O.(1E-2 dilution). Take 1 ml of this and dilute it       into 9 ml sterile ddH2O (1E-3 dilution).  3.) Heat the suspension (1E-3 dilution) for 16 hours at 45 C.  4.) Plate 0.1 ml and 0.2 ml ( 1E-4, 2E-4 dilution ) onto sodium     caseinate plates.  5.) Inxcubate for 5-7 days at room temperature.         Many different actinomycetes will appear. A large         percentage will probably produce a blue diffusible        compound similar in color to that of actinorhodin.  Notes: The soil can be pretreated by air drying for 48 hrs. This         will decrease the number of non-spore forming bacteria.        The addition of antibiotics,such as rifamycin, to richer         selection media can also select for actinomycetes.        Erythromycin will increase the percentage of Streptomyces         species isolated and other antibiotics will have differing        effects.  Sodium Caseinate Agar  Sodium Caseinate    0.20 g/l K2HPO4              0.50 g/l MgSO4               0.20 g/l FeCl3               0.01 g/l Agar                15.0-16.0 g/l pH                  6.5-6.7