[An electron microscopic study of the vegetative mycelia of Actinomyces flavus during flavofungin biosynthesis]

The vegetative mycelium of a submerged culture of Actinomyces flavus 12 was studied by complex electron microscopy (negative and positive contrasting, cryofractography) in the course of biosynthesis of flavofungin. The antibiotic is accumulated first in the cytoplasm as singular small granules which later grow larger. Accumulation of flavofungin is accompanied with destruction of the cytoplasm, nucleoid and other structures. Secretion of the antibiotic is supposed to be accomplished according to holocrine type.