Actinobacteria

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"Actinobacteria"
Actinomyces israelii.jpg
Scanning electron micrograph of Actinomyces israelii .
Scientific classification Red Pencil Icon.png
Domain: Bacteria
(unranked): Terrabacteria
Phylum: Actinobacteria
Goodfellow 2012 [1]
Classes [2]
Synonyms
  • "Actinobacteraeota" Oren et al. 2015
  • "Actinobacteriota" Whitman et al. 2018
  • "Actinobacteria" Stackebrandt, Rainey & Ward-Rainey 1997
  • "Actinobacteria" (ex Margulis 1974) Cavalier-Smith 2020
  • "Actinomycetes" Krasil'nikov 1949

The "Actinobacteria" are a phylum of mostly Gram-positive bacteria. They can be terrestrial or aquatic. [3] 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, Actinobacteria 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 (the actinomycetes), reflects that they were long believed to be fungi. Some soil actinobacteria (such as Frankia ) 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.

Contents

Beyond the great interest in "Actinobacteria" for their soil role, much is yet to be learned about them. Although currently understood primarily as soil bacteria, they might be more abundant in fresh waters. [4] "Actinobacteria" is one of the dominant bacterial phyla and contains one of the largest of bacterial genera, Streptomyces . [5] Streptomyces and other actinobacteria are major contributors to biological buffering of soils. [6] They are also the source of many antibiotics.

The "Actinobacteria" genus Bifidobacterium is the most common bacterium in the microbiome of human infants. [7] Although adults have fewer bifidobacteria, intestinal bifidobacteria help maintain the mucosal barrier and reduce lipopolysaccharide in the intestine. [8]

Although some of the largest and most complex bacterial cells belong to the "Actinobacteria", the group of marine Actinomarinales has been described as possessing the smallest free-living prokaryotic cells. [9]

Some Siberian or Antarctic "Actinobacteria" is said to be the oldest living organism on Earth, frozen in permafrost at around half a million years ago. [10] [11] The symptoms of life were detected by CO
2 release from permafrost samples 640 kya or younger. [12]

General

Most "Actinobacteria" of medical or economic significance are in class Actinobacteria , and belong to the order Actinomycetales . While many of these cause disease in humans, Streptomyces is notable as a source of antibiotics.[ citation needed ]

Of those "Actinobacteria" not in the Actinomycetales, Gardnerella is one of the most researched. Classification of Gardnerella is controversial, and MeSH catalogues it as both a Gram-positive and Gram-negative organism. [13]

"Actinobacteria", especially Streptomyces spp., are recognized as the producers of many bioactive metabolites that are useful to humans in medicine, such as antibacterials, [14] antifungals, [15] antivirals, antithrombotics, immunomodifiers, antitumor drugs, and enzyme inhibitors; and in agriculture, including insecticides, herbicides, fungicides, and growth-promoting substances for plants and animals. [16] [17] "Actinobacteria"-derived antibiotics that are important in medicine include aminoglycosides, anthracyclines, chloramphenicol, macrolide, tetracyclines, etc.

"Actinobacteria" have high guanine and cytosine content in their DNA. [18] The G+C content of "Actinobacteria" can be as high as 70%, though some may have a low G+C content. [19]

Analysis of glutamine synthetase sequence has been suggested for phylogenetic analysis of the "Actinobacteria". [20]

Phylogeny

The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN). [2] The phylogeny is based on whole-genome analysis. [21]

 
Actinobacteria (phylum)
 

Rubrobacteria

 
 
 

Thermoleophilia

 
 
 

Coriobacteriia

 
 
 

Acidimicrobiia

 
 
 

Nitriliruptoria

 
 

Actinobacteria (class)

 
 
 
 
 
 
outgroup

Chloroflexi

 
 

See also

Related Research Articles

Gram-positive bacteria Bacteria that give a positive result in the Gram stain test

In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall.

<i>Gardnerella vaginalis</i> Species of bacterium

Gardnerella is a genus of Gram-variable-staining facultative anaerobic bacteria of which Gardnerella vaginalis is the only species. The organisms are small non-spore-forming, nonmotile coccobacilli.

The Thermomicrobia is a group of thermophilic green non-sulfur bacteria. Based on species Thermomicrobium roseum and Sphaerobacter thermophilus, this bacteria class has the following description:

<i>Micromonosporaceae</i> Family of bacteria

Micromonosporaceae is a family of bacteria of the class Actinobacteria. They are gram-positive, spore-forming soil organisms that form a true mycelium.

<i>Streptomyces</i> Genus of bacteria

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 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.

<i>Actinomycetales</i> Order of Actinobacteria

The Actinomycetales are an order of Actinobacteria. 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 actinobacteria 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.

Actinomycetia Class of bacteria

The Actinomycetia are a class of bacteria.

<i>Bifidobacteriaceae</i> Family of bacteria

The Bifidobacteriaceae are the only family of bacteria in the order Bifidobacteriales. According to the 16S rRNA-based LTP release 106 published by 'The All-Species Living Tree' Project, the order Bifidobacteriales is a clade nested within the suborder Micrococcineae, also the genus Bifidobacterium is paraphyletic to the other genera within the family, i.e. the other genera are nested within Bifidobacterium.

Streptomycetaceae Family of bacteria

The Streptomycetaceae are a family of Actinobacteria, making up the monotypic order Streptomycetales. It includes the important genus Streptomyces. This was the original source of many antibiotics, namely streptomycin, the first antibiotic against tuberculosis.

Actinomycetaceae Family of bacteria

The Actinomycetaceae are a family of bacteria in the order Actinomycetales that contains the medically important genus Actinomyces. These organisms are closely related to the mycobacteria, but were originally classified as fungi because they were thought to be transitional forms between bacteria and fungi.

The Pseudonocardiaceae are a family of bacteria in the order Actinomycetales and the only member of the suborder Pseudonocardineae.

<i>Streptomyces griseus</i> Species of bacterium

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.

Bacterial phyla Phyla or divisions of the domain Bacteria

Bacterial phyla constitute the major lineages of the domain Bacteria. While the exact definition of a bacterial phylum is debated, a popular definition is that a bacterial phylum is a monophyletic lineage of bacteria whose 16S rRNA genes share a pairwise sequence identity of ~75% or less with those of the members of other bacterial phyla.

Streptomyces thermocarboxydovorans is a streptomycete bacterium species. It is moderately thermophilic and carboxydotrophic, with type strain AT52.

Streptomyces thermocarboxydus is a streptomycete bacterium species. It is moderately thermophilic and carboxydotrophic, with type strain AT37.

Streptomyces antibioticus is a gram-positive bacterium discovered in 1941 by Nobel-prize-winner Selman Waksman and H. Boyd Woodruff. Its name is derived from the Greek "strepto-" meaning "twisted", alluding to this genus' chain-like spore production, and "antibioticus", referring to this species' extensive antibiotic production. Upon its first characterization, it was noted that S. antibioticus produces a distinct soil odor.

Streptomyces africanus is a bacterium species from the genus of Streptomyces which has been isolated from soil in Cape Town in South Africa.

Streptomyces ascomycinicus is a bacterium species from the genus of Streptomyces which has been isolated from soil from Kobe City in Japan. Streptomyces ascomycinicus produces ascomycin.

The Dermacoccaceae is a family of bacteria placed within the order of Actinomycetales. Bacteria af this familia are Gram-positive, non-spore-forming and non-motile. Dermacoccaceae bacteria occur on the skin.

The Dermatophilaceae is a Gram-positive family of bacteria placed within the order of Actinomycetales. Dermacoccaceae bacteria occur on animal and human skin and in fish guts.

References

  1. ↑ Goodfellow M (2012). "Phylum XXVI. Actinobacteria phyl. nov.". In Goodfellow M, Kämpfer P, Trujillo ME, Suzuki K, Ludwig W, Whitman WB (eds.). Bergey's Manual of Systematic Bacteriology. 5 (2nd ed.). New York, NY: Springer. pp. 33–34.
  2. 1 2 Euzéby JP, Parte AC. "Actinobacteria". List of Prokaryotic names with Standing in Nomenclature (LPSN). Retrieved June 7, 2021.
  3. ↑ Servin JA, Herbold CW, Skophammer RG, Lake JA (January 2008). "Evidence excluding the root of the tree of life from the actinobacteria". Mol. Biol. Evol. 25 (1): 1–4. doi: 10.1093/molbev/msm249 . PMID   18003601.
  4. ↑ Ghai R, Rodriguez-Valera F, McMahon KD, et al. (2011). Lopez-Garcia P (ed.). "Metagenomics of the water column in the pristine upper course of the Amazon river". PLOS ONE. 6 (8): e23785. Bibcode:2011PLoSO...623785G. doi: 10.1371/journal.pone.0023785 . PMC   3158796 . PMID   21915244.
  5. ↑ C.Michael Hogan.. 2010. Bacteria. Encyclopedia of Earth. eds. Sidney Draggan and C.J.Cleveland, National Council for Science and the Environment, Washington DC Archived 2011-05-11 at the Wayback Machine
  6. ↑ Ningthoujam, Debananda S.; Sanasam, Suchitra; Tamreihao, K; Nimaichand, Salam (November 2009). "Antagonistic activities of local actinomycete isolates against rice fungal pathogens". African Journal of Microbiology Research. 3 (11): 737–742.
  7. ↑ Turroni F, Peano C, Pass DA, Foroni E, Severgnini M, Claesson MJ, Kerr C, Hourihane J, Murray D, Fuligni F, Gueimonde M, Margolles A, De Bellis G, O'Toole PW, van Sinderen D, Marchesi JR, Ventura M (2012-05-11). "Diversity of bifidobacteria within the infant gut microbiota". PLOS ONE. 7 (5): e36957. Bibcode:2012PLoSO...736957T. doi: 10.1371/journal.pone.0036957 . PMC   3350489 . PMID   22606315.
  8. ↑ Pinzone MR, Celesia BM, Di Rosa M, Cacopardo B, Nunnari G (2012). "Microbial translocation in chronic liver diseases". International Journal of Microbiology. 2012: 694629. doi: 10.1155/2012/694629 . PMC   3405644 . PMID   22848224.
  9. ↑ Ghai R, Mizuno CM, Picazo A, Camacho A, Rodriguez-Valera F (2013). "Metagenomics uncovers a new group of low GC and ultra-small marine Actinobacteria". Scientific Reports. 3: 2471. Bibcode:2013NatSR...3E2471G. doi:10.1038/srep02471. PMC   3747508 . PMID   23959135.
  10. ↑ Sussman: Oldest Plants, The Guardian, 2 May 2010
  11. ↑ "It's Okay to be Smart • the oldest living thing in the world: These". Archived from the original on 2018-07-13. Retrieved 2018-07-13.
  12. ↑ Johnson, S. S.; Hebsgaard, M. B.; Christensen, T. R.; Mastepanov, M.; Nielsen, R.; Munch, K.; Brand, T.; Gilbert, M. T. P.; Zuber, M. T.; Bunce, M.; Ronn, R.; Gilichinsky, D.; Froese, D.; Willerslev, E. (2007). "Ancient bacteria show evidence of DNA repair". Proceedings of the National Academy of Sciences. 104 (36): 14401–14405. Bibcode:2007PNAS..10414401J. doi: 10.1073/pnas.0706787104 . PMC   1958816 . PMID   17728401.
  13. ↑ Gardnerella at the US National Library of Medicine Medical Subject Headings (MeSH)
  14. ↑ Mahajan, GB (2012). "Antibacterial agents from actinomycetes - a review". Frontiers in Bioscience. 4: 240–53. doi:10.2741/e373.
  15. ↑ Gupte, M.; Kulkarni, P.; Ganguli, B.N. (2002). "Antifungal Antibiotics". Appl. Microbiol. Biotechnol. 58 (1): 46–57. doi:10.1007/s002530100822. PMID   11831475. S2CID   8015426.
  16. ↑ Bressan, W (2003). "Biological control of maize seed pathogenic fungi by use of actinomycetes". Biocontrol. 48 (2): 233–240. doi:10.1023/a:1022673226324. S2CID   29320215.
  17. ↑ Atta, M.A (2009). "Antimycin-A Antibiotic Biosynthesis Produced by Streptomyces Sp. AZ-AR-262: Taxonomy, Fermentation, Purification and Biological Activities". Austral. J. Basic and Appl. Sci. 3: 126–135.
  18. ↑ Ventura, M.; Canchaya, C.; Tauch, A.; Chandra, G.; Fitzgerald, G. F.; Chater, K. F.; van Sinderen, D. (5 September 2007). "Genomics of Actinobacteria: Tracing the Evolutionary History of an Ancient Phylum". Microbiology and Molecular Biology Reviews. 71 (3): 495–548. doi:10.1128/MMBR.00005-07. hdl:11381/1721088. PMC   2168647 . PMID   17804669.
  19. ↑ Ghai R, McMahon KD, Rodriguez-Valera F (2012). "Breaking a paradigm:cosmopolitan and abundant freshwater actinobacteria are low GC". Environmental Microbiology Reports. 4 (1): 29–35. doi:10.1111/j.1758-2229.2011.00274.x. PMID   23757226.
  20. ↑ Hayward D, van Helden PD, Wiid IJ (2009). "Glutamine synthetase sequence evolution in the mycobacteria and their use as molecular markers for "Actinobacteria" speciation". BMC Evol. Biol. 9: 48. doi:10.1186/1471-2148-9-48. PMC   2667176 . PMID   19245690.
  21. ↑ Nouioui I, Carro L, García-López M, Meier-Kolthoff JP, Woyke T, Kyrpides NC, Pukall R, Klenk HP, Goodfellow M, Markus Göker M (2018). "Genome-Based Taxonomic Classification of the Phylum Actinobacteria". Front. Microbiol. 9: 2007. doi: 10.3389/fmicb.2018.02007 . PMC   6113628 . PMID   30186281.

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