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Streptomyces griseus

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Streptomyces griseus is a rod shaped, spore forming bacterium commonly found in soil. It helps to naturally decompose organic matter. It is a streptomycin producer and can also sometimes be found in deep sea sediment. Sometimes referred to as Actinomyces grisues, these becteria are infrequent pathogens meaning they are infectous agents however they only have a Biohazard Level of 1 meaning they are relatively harmless to humans.

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Classification

Domain: Bacteria
Phylum: Actinobacteria
Order: Actinomycetales
Family: Streptomycetaceae
Genus: Streptomyces

Facts

Gram Stain
Positive
Growth Temperature
26 degrees celsius
Respiration
Aerobic
Energy Requirment
Heterotrophic (organic matter)
Reproduction
Asexual
Motility
Non-motile
Growth Media
YMG agar, YMG broth
Biohazard Level
1

Industrial Usage/Economic Implications

Streptomyces grisues is very commonly used in the production of antobiotics as are alot bacteria from the Streptomyces genus. The first antibiotic reported from a bacterium comes from strains of this. Antibiotics specifically made from Streptomyces griseus include:
*Streptomycin (and other clinical derivatives)
*Cycloheximide
*Candicidin B
*Grisein
Streptomyces griseus was most famously used to treat tuberculosis when Streptomycin was derived
from it in 1943 by Dr. Selman Waksman and co-workers. It can also be used to produce the anti- cancer drug streptocin and is now thought to be a good bacterium to use in the purifying of water.
The video to the right discusses the use of streptomycin in crops and the implications this might have.

Antibiotics

The discovery of antibiotics has improved the health and quality of life of individuals drastically. Different Streptomyces griseus strains are able to produce different antibiotics that have been exploited by the human population.

Streptomycin
Is a powerful antibiotic used to treat severe illness. It was first used to treat tuberculosis. Streptomycin can only be administered to the patient by injection and is usually injected into large muscles.
Cycloheximde
Not used for a therapeutic antibiotic in humans but used commonly in biomedical research as it inhibits protein synthesis within the cells.
Candicidin B
Is used in candidiasis, which is a variety of infections caused by the fungi species Candida. It uses the antifungal hepteane macrolides from Streptomyces griseus .
Grisein
This has a much narrower antibiotic spectrum than streptomycin and other antibiotics produced by Streptomyces grieus strains. It is not effective on the likes of tuberculosis, for example. Bacteria resistance to grisein is more rapid than in other antibiotics.

Interesting Facts

  • Streptomyces griseus gives soil its "earthy" smell. This is because it produces an organic compound known as geosmin. Humans are very sensitive to the smell of geosmin.
  • This bacterium is also involved in a symbiotic relationship with an ant species from the genus Attini. It inhabits the cuticles of the ant and helps them to maintain the fungal gardens that they produce as it contains special toxins that maintain the main type of weed in the ants fungal garden.
  • The word "Streptomyces" derives from the Latin word "strepto" meaning twisted and the Greek word "mukes" meaning fungus. This mostly refers to the shape of the bacterium.
  • The linear chromosome of this bacterium has a very high G-C content of 72.2%.

More Information

There are many interesting journal articles that talk about Streptomyces griseus and it's uses, applications and other interesting information. For more information on this bacteria and studies into this bacteria some links are provided below: