Molds cultivation media

A low-fertility soil improver such as leaf mold can be incorporated as the bed is dug initially. This deep cultivation is useful where the soil is compacted. It results in a deep, fertile zone with an open, free-draining structure into which roots can easily penetrate. Medium- to high-fertility materials, if required, should only be mixed into the top 6-8 in (15-20 cm). Increases in yield are noticeable and plants cope better in drought. Make the edging at least 6 in (15 cm) high as the soil level will rise considerably. 

Derivation The mold is grown in a nutrient solution such as com steep liquor, lactose, or dextrose. After several days of cultivation the mold excretes penicillin into its hquid culture medium. This hquid is then filtered off, and the penicillin extracted and purified by countercurrent extraction with amyl acetate, adsorption on carbon, or other methods. Different varieties of penicillin are produced biosynthetically by adding the proper precursors to the nutrient solution. 

Blondin and Vezhinet (1988), Edersen et al. (1988) and Dubourdieu and Frezier (1990) applied this technique to identify etiological yeast strains. Sample preparation is relatively easy. The yeasts are cultivated in a liquid medium, collected during the log phase, and then placed in suspension in a warm agarose solution that is poured into a partitioned mold to form small plugs. 

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