The Actinomycetota are a diverse phylum of Gram-positive bacteria with high G+C content. They can be terrestrial or aquatic. They are of great economic importance to humans because agriculture and forests depend on their contributions to soil systems. In soil they help to decompose the organic matter of dead organisms so the molecules can be taken up anew by plants. While this role is also played by fungi, Actinomycetota are much smaller and likely do not occupy the same ecological niche. In this role the colonies often grow extensive mycelia, like a fungus would, and the name of an important order of the phylum, Actinomycetales, reflects that they were long believed to be fungi. Some soil actinomycetota live symbiotically with the plants whose roots pervade the soil, fixing nitrogen for the plants in exchange for access to some of the plant's saccharides. Other species, such as many members of the genus Mycobacterium, are important pathogens.
Streptomyces is the largest genus of Actinomycetota, and the type genus of the family Streptomycetaceae. Over 700 species of Streptomyces bacteria have been described. As with the other Actinomycetota, streptomycetes are gram-positive, and have very large genomes with high GC content. Found predominantly in soil and decaying vegetation, most streptomycetes produce spores, and are noted for their distinct "earthy" odor that results from production of a volatile metabolite, geosmin. Different strains of the same species may colonize very diverse environments.
Streptomyces griseus is a species of bacteria in the genus Streptomyces commonly found in soil. A few strains have been also reported from deep-sea sediments. It is a Gram-positive bacterium with high GC content. Along with most other streptomycetes, S. griseus strains are well known producers of antibiotics and other such commercially significant secondary metabolites. These strains are known to be producers of 32 different structural types of bioactive compounds. Streptomycin, the first antibiotic ever reported from a bacterium, comes from strains of S. griseus. Recently, the whole genome sequence of one of its strains had been completed.
Streptomyces scabiei is a streptomycete bacterium species found in soils around the world. Unlike most of the 500 or so Streptomyces species it is a plant pathogen causing corky lesions to form on tuber and root crops as well as decreasing the growth of seedlings. Along with other closely related species it causes the potato disease common scab, which is an economically important disease in many potato growing areas. It was first described in 1892, being classified as a fungus, before being renamed in 1914 and again in 1948. Several other species of Streptomyces cause similar diseases to S. scabiei but other, more closely related species, do not.
Streptomyces africanus is a bacterium species from the genus of Streptomyces which has been isolated from soil in Cape Town in South Africa.
Streptomyces albospinus is a bacterium species from the genus of Streptomyces which has been isolated from soil from the Akita City in Japan. Streptomyces albospinus produces spinamycine, phenamide, phenelfamycin G and phenelfamycin H.
Streptomyces anandii is a bacterium species from the genus Streptomyces which has been isolated from soil from in the region of Al-Taif in Saudi Arabia. Streptomyces anandii produces pentaene G8, gilvocarcin V, gilvocarcin M and gilvocarcin E.
Streptomyces ardus is a bacterium species from the genus Streptomyces which has been isolated from soil. Streptomyces ardus produces porfiromycin.
Streptomyces ascomycinicus is a bacterium species from the genus Streptomyces which has been isolated from soil from Kobe City in Japan. Streptomyces ascomycinicus produces ascomycin.
Streptomyces aureus is a bacterium species from the genus of Streptomyces which has been isolated from soil from the United Kingdom. Streptomyces aureus produces azirinomycin and thiostrepton.
Streptomyces deccanensis is an alkaliphilic bacterium species from the genus of Streptomyces which has been isolated from soil in the city Gulbarga in the Karnataka in India.
Streptomyces griseoviridis is a filamentous bacterium species from the genus Streptomyces, which was isolated from soil in Texas, United States. Streptomyces griseoviridis produces etamycin, griseoviridin, bactobolin, prodigiosin R1, actinobolin, and rosophilin. Streptomyces griseoviridis can be used to protect plants since it inhibits the growth of fungal pathogens.
Streptomyces gulbargensis is an alkalitolerant and thermotolerant bacterium species from the genus of Streptomyces which has been isolated from soil from Gulbarga in the Karnataka in India.
Streptomyces marokkonensis is a bacterium species from the genus of Streptomyces which has been isolated from the rhizosphere soil of the tree Argania spinosa in Morocco.
Streptomyces mayteni is a bacterium species from the genus of Streptomyces which has been isolated from roots from the plant Maytenus austroyunnanensis.
Streptomyces sanglieri is a bacterium species from the genus of Streptomyces which has been isolated from soil from a hay meadow. Streptomyces sanglieri produces the antibiotic lactonamycin Z.
Streptomyces thinghirensis is a bacterium species from the genus of Streptomyces which has been isolated from rhizosphere soil from the grape plant Vitis vinifera in Thinghir in Morocco.
Microbacterium azadirachtae is a Gram-positive, non-spore-forming and motile bacterium from the genus Microbacterium which has been isolated from the rhizoplane of the plant Azadirachta indica from the Botanical Garden of Coimbatore in India. Microbacterium azadirachtae can promote plant growth by producing phytohormones.
Azospirillum is a Gram-negative, microaerophilic, non-fermentative and nitrogen-fixing bacterial genus from the family of Rhodospirillaceae. Azospirillum bacteria can promote plant growth.
Streptomyces triticagri is a bacterium species from the genus of Streptomyces which has been isolated from rhizosphereic soil of the plant Triticum aestivum from Zhumadian in China.
