Streptomyces - Morphology

Morphology

The genus Streptomyces includes aerobic, Gram-positive, filamentous bacteria which produce well developed vegetative hyphae (between 0.5-2.0 µm in diameter) with branches. They form a complex substrate mycelium that aids in scavenging organic compounds from their substrates. Although the mycelium and the aerial hyphae that arises from them are amotile, mobility is achieved by dispersion of spores. Spore surfaces may be hairy, rugose, smooth, spiny or warty. In some species, aerial hyphae consist of long, straight filaments, which bear 50 or more spores at more or less regular intervals, arranged in whorls (verticils). Each branch of a verticil produces, at its apex, an umbel which carries from two to several chains of spherical to ellipsoidal smooth or rugose spores. Some strains form short chains of spores on substrate hyphae. Sclerotia-, pycnidia-, sporangia- and synnemata-like structures are produced by some strains.