Aerobic, Gram-stain-positive, non-acid-fast bacteria that form extensively branched substrate and aerial mycelia. Chemoorganotrophic, having an oxidative type of metabolism. The vegetative hyphae (0.5–2.0 µm in diameter) rarely fragment. The aerial mycelium forms chains of three to many spores at maturity. Some species show short chains of spores on the substrate mycelium and others form sclerotia, pycnidial-, sporangia-, and synnemata-like structures. The spores are nonmotile. Colonies are discrete and lichenoid, leathery, or butyrous. Often, colonies initially show a smooth surface, but later develop a weft of aerial mycelium that may appear floccose, granular, powdery, or velvety. Can produce a wide variety of pigments responsible for the color of the vegetative and aerial mycelia. Colored diffusible pigments may also be formed. Many strains are able to produce one or more antibiotic substances.
DNA G+C content (mol%): 66–78 (Tm).
Type species: Streptomyces albus
This genus contains microbial species that can reside in the human gastrointestinal tract. [PMC 4262072]
Microbial Abundance Data: Streptomyces (Percent of total population with standard deviation [PMID: 22698087])
