[Electron microscopic structure of the mycelium of Actinomyces chrysomallus, the producer of the antibiotic chrysomallin, during the stab fermentation process].

Ultrastructural changes in the mycelium of Actinomyces (Streptomyces) chrysomallus 2703 producing the antibiotic chrysomallin in the process of submerged fermentation are described. When the antibiotic was produced at a high rate, most hyphae remained viable for a long period of time and had the ultrastructure typical of the young cells of actinomycetes. At the same time, a number of degenerative changes due to aging were observed; these resulted in autolysis. A decrease in the antibiotic titre was accompanied with intensive sporulation in a considerable number of the submerged hyphae. Structural changes in the sporeforming hyphae distinctly differed from those in the vegetative ones: the cell walls became thicker and numerous septa were formed. The exogenous formation of submerged spores in the culture under study has been studied in detail for the first time.