| Streptomyces |
| Morphology | Streptomyces |
| CELLULAR |
| Staining | Gram-positive but not acid-alcohol fast. |
| Morphology | Vegetative hyphae (0.5-1.0 um in diameter) produce an extensively branched mycelium that rarely fragments. The aerial mycelium at maturity forms chains of three to many spores. A few species bear short chains of spores on the substrate mycelium. Sclerotia, pycnidialsporangia-, and synnemata-like structures may be formed by some species. Form discrete and lichenoid, leathery or butyrous colonies. Initially colonies are relatively smooth surfaced but later they develop a weft of aerial mycelium that may appear floccose, granular, powdery, or velvety. Produce a wide variety of pigments responsible for the colour of the vegetative and aerial mycelia |
| Motility | Spores are nonmotile. |
| Specialized structures |
| Division |
| COLONIAL |
| Solid surface | Coloured diffusible pigments may be formed |
| Liquid |
| Growth Parameters | Streptomyces |
| PHYSIOLOGICAL |
| Tropism | Chemoorganotrophic |
| Oxygen | Aerobes. oxidative type of metabolism |
| pH | optimum pH range for growth 6.5-8.0. |
| Temperature | Temperature optimum 25-35`C; some species grow at temperatures within the psychrophilic and thermophilic range; |
| Requirements | Use a wide range of organic compounds as sole sources of carbon for energy |
| Products | Generally reduce nitrates to nitrites and degrade adenine, esculin, casein, gelatin, hypoxanthine, starch, and L-tyrosine |
| Enzymes | Catalase positive |
| Unique features | . Many strains produce one or more antibiotics.,The cell wall peptidoglycan contains major amounts of L- diaminopimelic acid (L-DAP). They lack mycolic acids,contain major amounts of saturated, iso- and anteiso-fatty acids, possess either hexa- or octahydrogenated menaquinones with nine isoprene units as the predominant isoprenolog, and have complex polar lipid patterns that typically contain diphosphatidylglycerol, phosphatidylethanolamine, phospha- tidylinositol, and phosphatidylinositol mannosides.. |
| ENVIRONMENTAL |
| Habitat | They are widely distributed and abundant in soil including composts. |
| Lifestyle | |
| Pathogenicity | A few species are pathogenic for animals and man, others are phytopathogens |
| Distribution |
| Genome | Streptomyces |
| G+C Mol % | 69-78 (Tm) |
| Reference | Streptomyces |
| First citation | Waksman,S.A. and A.T. Henrici. 1943.The nomenclature and classification of the actinomycetes. J. Bacteriol. 46: 337-341 |
| The Prokaryotes | |
| Bergey's Systematatic | p 2452 S. T Williams, M. Goodfellow, and G. Anderson |
| Bergey's Determinative | p 668 |
| References |