The Actinomycetota are a diverse phylum of Gram-positive bacteria with high GC content. They can be terrestrial or aquatic. They are of great importance to land flora because of 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, as fungi do, 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.
Selman Abraham Waksman was a Jewish American inventor, Nobel Prize laureate, biochemist and microbiologist whose research into the decomposition of organisms that live in soil enabled the discovery of streptomycin and several other antibiotics. A professor of biochemistry and microbiology at Rutgers University for four decades, he discovered several antibiotics, and he introduced procedures that have led to the development of many others. The proceeds earned from the licensing of his patents funded a foundation for microbiological research, which established the Waksman Institute of Microbiology located at the Rutgers University Busch Campus in Piscataway, New Jersey (USA). In 1952, he was awarded the Nobel Prize in Physiology or Medicine for "ingenious, systematic, and successful studies of the soil microbes that led to the discovery of streptomycin." Waksman and his foundation later were sued by Albert Schatz, one of his Ph.D. students and the discoverer of streptomycin, for minimizing Schatz's role in the discovery.
Actinomyces is a genus of the Actinomycetia class of bacteria. They all are gram-positive and facultatively anaerobic, growing best under anaerobic conditions. Actinomyces species may form endospores, and while individual bacteria are rod-shaped, Actinomyces colonies form fungus-like branched networks of hyphae. The aspect of these colonies initially led to the incorrect assumption that the organism was a fungus and to the name Actinomyces, "ray fungus".
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.
The Actinomycetales is an order of Actinomycetota. A member of the order is often called an actinomycete. Actinomycetales are generally gram-positive and anaerobic and have mycelia in a filamentous and branching growth pattern. Some actinomycetes can form rod- or coccoid-shaped forms, while others can form spores on aerial hyphae. Actinomycetales bacteria can be infected by bacteriophages, which are called actinophages. Actinomycetales can range from harmless bacteria to pathogens with resistance to antibiotics.
Albert Israel Schatz was an American microbiologist and academic who discovered streptomycin, the first antibiotic known to be effective for the treatment of tuberculosis. He graduated from Rutgers University in 1942 with a bachelor's degree in soil microbiology, and received his doctorate from Rutgers in 1945. His PhD research led directly to the discovery of streptomycin.
Burkholderia cepacia complex (BCC) is a species complex consisting of Burkholderia cepacia and at least 20 different biochemically similar species of Gram-negative bacteria. They are catalase-producing and lactose-nonfermenting. Members of BCC are opportunistic human pathogens that most often cause pneumonia in immunocompromised individuals with underlying lung disease. Patients with sickle-cell haemoglobinopathies are also at risk. The species complex also attacks young onion and tobacco plants, and displays a remarkable ability to digest oil.
Boromycin is a bacteriocidal polyether-macrolide antibiotic. It was initially isolated from the Streptomyces antibioticus, and is notable for being the first natural product found to contain the element boron. It is effective against most Gram-positive bacteria, but is ineffective against Gram-negative bacteria. Boromycin kills bacteria by negatively affecting the cytoplasmic membrane, resulting in the loss of potassium ions from the cell. Boromycin has not been approved as a drug for medical use.
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.
Saccharopolyspora erythraea is a species of actinomycete bacteria within the genus Saccharopolyspora.
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 avermitilis is a species of bacteria in the genus Streptomyces. This bacterium was discovered by Satoshi Ōmura in Shizuoka Prefecture, Japan.
Actinoplanes italicus is distinguished by the cherry-red color of its vegetative mycelium, and by the production of soluble pigments. It is also known to produce sporangia when cultured on starch or skim milk agar. Very few strains have been found and cultured, thus A. italicus is relatively uncharacterized.
Rathayibacter toxicus is a phytopathogenic bacterium known for causing annual ryegrass toxicity (ARGT) commonly found in South and Western Australia.
Streptomyces albidoflavus is a bacterium species from the genus of Streptomyces which has been isolated from soil from Poland. Streptomyces albidoflavus produces dibutyl phthalate and streptothricins.
Streptomyces lavendulae is a species of bacteria from the genus Streptomyces. It is isolated from soils globally and is known for its production of medically useful biologically active metabolites. To see a photo of this organism click here.
In microbiology, the term isolation refers to the separation of a strain from a natural, mixed population of living microbes, as present in the environment, for example in water or soil, or from living beings with skin flora, oral flora or gut flora, in order to identify the microbe(s) of interest. Historically, the laboratory techniques of isolation first developed in the field of bacteriology and parasitology, before those in virology during the 20th century.
Streptomyces sp. myrophorea, isolate McG1 is a species of Streptomyces, that originates from a (ethnopharmacology) folk cure in the townland of Toneel North in Boho, County Fermanagh. This area was previously occupied by the Druids and before this neolithic people who engraved the nearby Reyfad stones. Streptomyces sp. myrophorea is inhibitory to many species of ESKAPE pathogens, can grow at high pH (10.5) and can tolerate relatively high levels of radioactivity.
Peptidiphaga gingivicola is a Gram-positive, non-spore forming, coccus shaped bacterium. Coccus are spherical and generally round in shape. Coccus are differentiated by their groupings that can range from chains, groups, or grape-like clusters. Peptidiphaga gingivicola was observed to grow in groups of 2-5 cocci between 0.2-0.9 mm in diameter. Growth was observed when cultured under anaerobic conditions between 33 and 40 degrees celsius on Blood Brucella agar for 4 days. Peptidiphaga gingivicola has been cultured from patients with periodontal disease, primarily caused by bacterial plaque formation on the gum and teeth of the oral cavity. The microbe is known to break down peptides of the gum causing tissue damage and tooth decay, leading to serious implications for oral health.
Actinomyces massiliensis is an anaerobic, mesophilic, Gram-positive bacterium originally isolated from a human blood sample and belonging to the genus Actinomyces.
