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11) Soil-water Medium (E.G. Pringsheim, Jour.
Ecology 33: 193-204, 1946)
Variations of this medium are for non-sterile
culture, especially for isolation purposes and for
growing algae in order to secure "normal" growth
forms. Success with soil-water media depends on
the selection of a suitable garden soil. This soil
should be of medium, but not too great humus
content and should not have been recently fertil-
ized with commercial fertilizers. Soils with a high
clay content are usually not the most suitable for
most organisms.
A variety of soil-water media can be made suing
a basic formula to which are added certain ad-
ditional materials. The basic soil-water medium is
made by placing approximately 5 mg soil per mL
(5g per liter) Pyrex-distilled water. The tube is then
plugged with cotton and autoclaved for 1 hour.
A number of algae such as Spirogyra grow well in
this basic medium. For most persumptively photo-
trophic algae which thrive in an alkaline
medium, a small pinch of powdered CaCO3 is
placed in the bottom of the test tube before the
soil and water are added.
Some algae like Euglena, Polytoma, Astasia, and
others require additional complex nitrogenous
or carbon com-pounds not present in the basic
formula.
In the case of Euglena, the best results have been
obtained by adding ¼ of a garden pea cotyledon
to the basic medium (including CaCO3) before
autoclaving. For the colorless forms, the addition
of a barley grain before autoclaving supplied the
necessary carbon source.
12) Trebouxia Agar (V. Ahmadjian, personal
communication)
For each 1000 mL of medium required:
Bristol's solution ([2], above) 850.0 mL
Soil-water supernatant 140.0 mL
Proteose peptone 10.0 g
Glucose 20.0 g
Agar 15.0 g
13) Volvocacean Agar (E. G. Pringsheim, personal
communication)
For each 1000 mL of medium required:
Waris solution (do not adjust pH) 800.0 mL
Euglena medium 200.0 mL
Agar 10.0 g
14) Waris Solution (H. Waris, Physiol. Plant. 6: 538-543,
1953)
To 1000 mL of Pyrex-distilled water add 1 mL of the
following solutions:
10% KNO3
2% MgSO4 • 7 H2O
2% (NH4)2 HPO4
5% CaSO4
Iron Sequestrene solution.
Adjust pH to 6.0 using 0.01 N HCl and 0.01 N KOH.
Iron sequestrine solution is composed of the
following:
Sequestrine AA 2.61 g
FeSO4 • 7 H2O 2.49 g
1 N KOH 27.0 mL
Pyrex-distilled water 500.0 mL
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