Streptomyces griseus
Encyclopedia
Streptomyces griseus is a member bacterial species
of the genus
Streptomyces
and are commonly found in soil. A few strains
have been also reported from deep sea sediments. These are Gram positive bacterium with high GC content. Along with most other streptomycetes S. griseus strains are well known producer of antibiotics and other such commercially significant secondary metabolites. These strains are known to be producers of 32 different structural types of bioactive compounds. The first antibiotic that was ever reported from a bacterium comes from strains of S. griseus. Recently the whole genome sequence of one of its strains had been completed.
The taxonomic history of S. griseus and its phylogenetically related strains have been turbulent. S. griseus was first described by Waksman and Henrici in 1948. The interest towards these strains was sought because of their ability to produce streptomycin
, a compound which demonstrated significant bactericidal activity against organisms such as Yersinia pestis
(the causative agent of plague) and Mycobacterium tuberculosis
(the causative agent of tuberculosis). For his work on these strains of bacteria and the antibiotic they produce, Waksman would later be awarded a Nobel Prize
.
and is the type genus of the family Streptomycetaceae. These are Gram positive bacterium with high GC content and are characterised by a complex secondary metabolism
. They produce over two-thirds of the clinically useful antibiotic
s of natural origin . Streptomycetes are found predominantly in soil
and in decaying vegetation, and most produce spores. Streptomycetes are noted for their distinct "earthy" odor which results from production of a volatile metabolite
, geosmin
.
values. Although these organisms grow on a wide range of pH (from 5 to 11), they show a growth optimum at pH 9. They produce grey spore
mass and grey-yellow reverse pigments when they grow as colonies. The spores have smooth surface and are arranged as straight chains.
have been used. A whole genome sequence was recently carried out on IFO 13350 strain of S. griseus.
, deep sea sediments and coastal beach and dune sand systems. Recent studies have indicated that the strains of S. griseus might be undergoing ecology specific evolution giving rise to genetic variation with the specific ecology, termed as ecovars.
in a S. griseus strain in 1943.
The discovery of streptomycin, an anti-tuberculosis
antibiotic, earned Waksman the Nobel Prize
in 1952.
Now it is known that the strains of this species are a rich source of antibiotics and are known to produce 32 different structural types of commercially significant secondary metabolites. Furthermore, the genomic studies have revealed that a single strain of S. griseus IFO 13350 has the capacity to produce 34 different secondary metabolites.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Streptomyces
Streptomyces
Streptomyces is the largest genus of Actinobacteria and the type genus of the family Streptomycetaceae. Over 500 species of Streptomyces bacteria have been described. As with the other Actinobacteria, streptomycetes are gram-positive, and have genomes with high guanine and cytosine content...
and are commonly found in soil. A few strains
Strain (biology)
In biology, a strain is a low-level taxonomic rank used in three related ways.-Microbiology and virology:A strain is a genetic variant or subtype of a micro-organism . For example, a "flu strain" is a certain biological form of the influenza or "flu" virus...
have been also reported from deep sea sediments. These are Gram positive bacterium with high GC content. Along with most other streptomycetes S. griseus strains are well known producer of antibiotics and other such commercially significant secondary metabolites. These strains are known to be producers of 32 different structural types of bioactive compounds. The first antibiotic that was ever reported from a bacterium comes from strains of S. griseus. Recently the whole genome sequence of one of its strains had been completed.
The taxonomic history of S. griseus and its phylogenetically related strains have been turbulent. S. griseus was first described by Waksman and Henrici in 1948. The interest towards these strains was sought because of their ability to produce streptomycin
Streptomycin
Streptomycin is an antibiotic drug, the first of a class of drugs called aminoglycosides to be discovered, and was the first antibiotic remedy for tuberculosis. It is derived from the actinobacterium Streptomyces griseus. Streptomycin is a bactericidal antibiotic. Streptomycin cannot be given...
, a compound which demonstrated significant bactericidal activity against organisms such as Yersinia pestis
Yersinia pestis
Yersinia pestis is a Gram-negative rod-shaped bacterium. It is a facultative anaerobe that can infect humans and other animals....
(the causative agent of plague) and Mycobacterium tuberculosis
Mycobacterium tuberculosis
Mycobacterium tuberculosis is a pathogenic bacterial species in the genus Mycobacterium and the causative agent of most cases of tuberculosis . First discovered in 1882 by Robert Koch, M...
(the causative agent of tuberculosis). For his work on these strains of bacteria and the antibiotic they produce, Waksman would later be awarded a Nobel Prize
Nobel Prize
The Nobel Prizes are annual international awards bestowed by Scandinavian committees in recognition of cultural and scientific advances. The will of the Swedish chemist Alfred Nobel, the inventor of dynamite, established the prizes in 1895...
.
Genus Streptomyces
Streptomyces is the largest genus of the ActinobacteriaActinobacteria
Actinobacteria are a group of Gram-positive bacteria with high guanine and cytosine content. They can be terrestrial or aquatic. Actinobacteria is one of the dominant phyla of the bacteria....
and is the type genus of the family Streptomycetaceae. These are Gram positive bacterium with high GC content and are characterised by a complex secondary metabolism
Secondary metabolism
Secondary metabolism is a term for pathways and small molecule products of metabolism that are not absolutely required for the survival of the organism. Examples of the products include antibiotics and pigments. To distinguish non-secondary metabolism, the term basic metabolism is sometimes used...
. They produce over two-thirds of the clinically useful antibiotic
Antibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
s of natural origin . Streptomycetes are found predominantly in soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
and in decaying vegetation, and most produce spores. Streptomycetes are noted for their distinct "earthy" odor which results from production of a volatile metabolite
Metabolite
Metabolites are the intermediates and products of metabolism. The term metabolite is usually restricted to small molecules. A primary metabolite is directly involved in normal growth, development, and reproduction. Alcohol is an example of a primary metabolite produced in large-scale by industrial...
, geosmin
Geosmin
Geosmin, which literally translates to "earth smell", is an organic compound with a distinct earthy flavour and aroma, and is responsible for the earthy taste of beets and a contributor to the strong scent that occurs in the air when rain falls after a dry spell of weather or when soil is...
.
Using S. griseus to Clean Water
Streptomyces griseus has been used as a plentiful source for antibiotics for a long time but is now beginning to come upon a new field, the purifying of water. In a recent test (as of 2010) it was shown that Streptomyces g. was able to reduce Copper (II) Nitrate levels in water from 1mg/L (a toxic level) to .1 mg/L which still not preferable but not as toxic. In addition it was able to bring down arsenic levels in water from 0.5 mg/L to 0.4 mg/L. The reason Streptomyces griseus is able to remove these contaminants is quite simple, the positively charged contaminants are attracted to the negatively charged cell walls of the Streptomyces g. then mucopolysaccharides bond the two together.Physiology and morphology
It has been recently demonstrated that S. griseus and its related strains are alkaliphilic, i.e., they grow best at alkaline pHPH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
values. Although these organisms grow on a wide range of pH (from 5 to 11), they show a growth optimum at pH 9. They produce grey spore
Spore
In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...
mass and grey-yellow reverse pigments when they grow as colonies. The spores have smooth surface and are arranged as straight chains.
Taxonomy
Like other streptomycetes, S. griseus have a high GC content in their genome with an average of 72.2%. The species was first described by Waksman and Henrici in 1948. The taxonomy of S. griseus and their evolutionarily related strains have been a considerable source of confusion for microbial systematists. 16S rRNA gene sequence data has been used to recognise the related strains, and are called S. griseus 16S rRNA gene clade. The strains of this clade have homogeneous phenotypic properties but show substantial genotypic heterogenecity based on genomic data. Several attempts are still made to solve this issue where techniques such as DNA:DNA homology and Multilocus sequence typingMultilocus sequence typing
Multilocus sequence typing is a technique in molecular biology for the typing of multiple loci. The procedure characterizes isolates of bacterial species using the DNA sequences of internal fragments of multiple housekeeping genes...
have been used. A whole genome sequence was recently carried out on IFO 13350 strain of S. griseus.
Ecology of S. griseus
Streptomyces griseus strains have been isolated from various ecologies including stell waste tips, rhizosphereRhizosphere
The rhizosphere is the narrow region of soil that is directly influenced by root secretions and associated soil microorganisms. Soil which is not part of the rhizosphere is known as bulk soil. The rhizosphere contains many bacteria that feed on sloughed-off plant cells, termed rhizodeposition, and...
, deep sea sediments and coastal beach and dune sand systems. Recent studies have indicated that the strains of S. griseus might be undergoing ecology specific evolution giving rise to genetic variation with the specific ecology, termed as ecovars.
Antibiotics from S. griseus
Interest in the genus Streptomyces for antibiotics came after the discovery of the antibiotic streptomycinStreptomycin
Streptomycin is an antibiotic drug, the first of a class of drugs called aminoglycosides to be discovered, and was the first antibiotic remedy for tuberculosis. It is derived from the actinobacterium Streptomyces griseus. Streptomycin is a bactericidal antibiotic. Streptomycin cannot be given...
in a S. griseus strain in 1943.
The discovery of streptomycin, an anti-tuberculosis
Tuberculosis
Tuberculosis, MTB, or TB is a common, and in many cases lethal, infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis. Tuberculosis usually attacks the lungs but can also affect other parts of the body...
antibiotic, earned Waksman the Nobel Prize
Nobel Prize
The Nobel Prizes are annual international awards bestowed by Scandinavian committees in recognition of cultural and scientific advances. The will of the Swedish chemist Alfred Nobel, the inventor of dynamite, established the prizes in 1895...
in 1952.
Now it is known that the strains of this species are a rich source of antibiotics and are known to produce 32 different structural types of commercially significant secondary metabolites. Furthermore, the genomic studies have revealed that a single strain of S. griseus IFO 13350 has the capacity to produce 34 different secondary metabolites.