full preparation protocol detailed in Media Recipes used in ANACC
Soil extract is an adaptation of E.G. Pringsheim’s biphasic soil-water medium and is a component of some of our media. As the chemical composition is not well-defined and may vary from batch to batch its use in experimental situations is not recommended, however in our experience certain species will not grow well without it and soil extract is added for both culture maintenance and experimental studies. Soil must be collected from a natural uncultivated environment or a rich garden loam may be suitable. No fungicides, insecticides, garden fertilizers or fresh manure should be present. At ANACC, topsoil from a local sandy bushland environment has proved to have particularly beneficial growth promoting properties. Soil from clay or other soil types are less suitable in our experience. Soil should not be stored or processed in the algal culture laboratory, since it is a potent source of unwanted microorganisms. Soil should be aged under moist conditions (preferably for 6 months or more) and then kept dry and away from light. An extensive list of modified Soil Water media developed for a range of microalgae from specific environments can be found on the UTEX website (The Culture Collection of Algae at the University of Texas) http://www.utex.org/.