|Scanning electron micrograph of Actinomyces israelii.|
Stackebrandt et al. 1997
|Subclasses & Orders|
Actinobacteria is a phylum of Gram-positive bacteria with high guanine and cytosine content in their DNA. The G+C content of Actinobacteria can be as high as 70%, though some may have a low G+C content. They can be terrestrial or aquatic. Although understood primarily as soil bacteria, they might be more abundant in freshwaters. Actinobacteria is one of the dominant bacterial phyla and contains one of the largest of bacterial genera, Streptomyces. Analysis of glutamine synthetase sequence has been suggested for phylogenetic analysis of Actinobacteria.
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.
- General 1
- Phylogeny 2
- See also 3
- References 4
- Further reading 5
- External links 6
Most Actinobacteria of medical or economic significance are in subclass Actinobacteridae, and belong to the order: Actinomycetales. While many of these cause disease in humans, Streptomyces is notable as a source of antibiotics.
Of those Actinobacteria not in Actinomycetales,
- Actinomycetes genome database
- Pandey, B.; Ghimire, P.; Agrawal, V.P. (January 12–15, 2004). Studies on the antibacterial activity of the Actinomycetes isolated from the Khumbu Region of Nepal (PDF). International Conference on the Great Himalayas: Climate, Health, Ecology, Management and Conservation. Kathmandu.
- Baltz, R.H. (2005). "Antibiotic discovery from actinomycetes: Will a renaissance follow the decline and fall?". SIM News 55: 186–196.
- Baltz, R.H. (2007). "Antimicrobials from Actinomycetes: Back to the Future".
- 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.
- 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.
- 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.
- Ghai R, Rodriguez-Valera F, McMahon KD; et al. (2011). Lopez-Garcia, Purification, ed. "Metagenomics of the water column in the pristine upper course of the Amazon river". PloS ONE 6 (8): e23785.
- C.Michael Hogan. 2010. . Encyclopedia of Earth. eds. Sidney Draggan and C.J.Cleveland, National Council for Science and the Environment, Washington DCBacteria
- 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.
- 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.
- Gardnerella at the US National Library of Medicine Medical Subject Headings (MeSH)
- Mahajan, GB (2012). "Antibacterial agents from actinomycetes - a review". Frontiers in Bioscience 4: 240–53.
- Gupte, M.; Kulkarni, P.; Ganguli, B.N. (2002). "Antifungal Antibiotics". Appl. Microbiol. Biotechnol 58: 46–57.
- Bressan, W (2003). "Biological control of maize seed pathogenic fungi by use of actinomycetes". Biocontrol 48 (2): 233–240.
- Atta, M.A (2009). Austral. J. Basic and Appl. Sci. 3: 126–135.
- Ningthoujam, Debananda S.; Tamreihao, SuchitraSanasam K.; Nimaichand, Salam (2009). "Test". Afr. J. Microbiol. Res. 3 (11): 737–742.
- J.P. Euzéby. "Actinobacteria".
- Sayers; et al. "Actinobacteria".
♪ Prokaryotes where no pure (axenic) cultures are isolated or available, i. e. not cultivated or can not be sustained in culture for more than a few serial passages
♠ Strains found at the National Center for Biotechnology Information (NCBI) but not listed in the List of Prokaryotic names with Standing in Nomenclature (LSPN)
The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN)  and National Center for Biotechnology Information (NCBI) and the phylogeny is based on 16S rRNA-based LTP release 106 by The All-Species Living Tree Project 
Streptomyces and other actinobacteria are major contributors to biological buffering of soils and have roles in organic matter decomposition conductive to crop production.
Actinobacteria, especially Streptomyces sp., are recognized as the producers of many bioactive metabolites that are useful to humans in medicine, such as antibacterials, antifungals, antivirals, antithrombotics, immunomodifiers, anti-tumor drugs and enzyme inhibitors; and in agriculture, including insecticides, herbicides, fungicides and growth promoting substances for plants and animals. Actinobacteria-derived antibiotics that are important in medicine include aminoglycosides, anthracyclines, chloramphenicol, macrolide, tetracyclines etc.