Composition and Ultrastructure of Streptomyces venezuelae

Abstract

Streptomyces venezuelae is a filamentous bacterium with branching vegetative hyphae embedded in the substrate and aerial hyphae bearing spores. The exterior of the spore is inlaid with myriads of tiny rods which can be removed with xylene. The spore wall is approximately 30 nanometers thick. Occasionally, it can be seen that the plasma membrane and the membranous bodies within a spore are connected. The spore's germ plasm is not separated from the cytoplasm by a nuclear envelope. The cell walls of the vegetative hyphae, which are about 15 nanometers thick, are structurally and chemically similar to those of gram-positive bacteria. The numerous internal membranous bodies, some of which arise from the plasma membrane of the vegetative hypha, may be vesicular, whirled, or convoluted. Membranous bodies are usually prominent at the hyphal apices and are associated with septum formation. The germ plasm is an elongate, contorted, centrally placed area of lower electron density than the hyphal cytoplasm. The spores differ from the vegetative hyphae, not only in fine structure, but also in the arginine and leucine contents of their total cellular proteins.

Peptidoglycan types of bacterial cell walls and their taxonomic implications.

“…Almost all of the studies on the chemical composition of the cell walls of these organisms are restricted to qualitative amino acid analyses (34,46,68,69,76,218,219,225,257,372,375,428). The primary structure of the peptidoglycans has been determined in only a very few cases.…”

Rapid Formation of Protoplasts of Streptomyces griseoflavus and Their Fine Structure

“…Amino acid analysis showed that C-cell walls contained more alanine than G-cell walls but both contained approximately equimolar amounts of DAP and lysine. According to Cummins and Harris [2] and Bradley and Ritzi [1], chemical compositions of Streptomyces species cell walls were reported to be amino acids and amino sugars such as alanine, glutamic acid, glycine, muramic acid, DAP and glucosamine. DeWeese et al [3] reported that Actinomyces propionicus differed significantly from other Actinomyces species in that it contained DAP and lysine as major cell wall components.…”

Trilamellar membranes surrounding nucleoids of Streptomyces levoris 1331 and Streptomyces lividans 66 after infection by Streptomyces phage SH12

“…Streptomycetes are prokaryotic organisms which are characterized by the lack of membrane structures surrounding their nucleoids [ 1,[4][5][6]13,16,17]. Studying the intracellular development of several newly isolated Streptomyces phage by electron microscopy, we observed trilamellar membranes surrounding the nucleoids of the host organism after infection by phage SH12.…”