The Growth and Metabolic Behavior of Streptomyces Venezuelae in Liquid Culture

SUMMARY

The “overall picture” of the growth, the morphological development and the uptake of the various components of a chemically defined medium during the culturing of Streptomyces venezuelae is for the most part straightforward. Spores germinate and give rise to hyphae which in turn form a loose mycelial weft. Later the weft changes to a more compact bundle with a dense center surrounded by young growing hyphae. The dry weight of the culture increases during this period; the carbon source, glycerol, disappears at about the time growth ceases. Lactic acid is utilized slightly and only in the period of glycerol utilization. During this time the medium is rapidly depleted of the nitrate ions, and ammonia is released, thereby increasing the hydroxyl ion concentration. Since the nitrate disappears long before the glycerol and before the weight of mycelium reaches its maximum, its assimilation into cellular material must be limited by the relatively low rate of absorption of the carbon source. After growth has reached its maximum, sporulation occurs and the mycelium tends to disintegrate. At this time the total soluble nitrogen in the medium increases because of the lysis of some mycelium.