Exiguobacterium aurantiacum

Exiguobacterium aurantiacum is a Gram-positive, alkaliphilic, halotolerant, and non-spore-forming bacterium.[2] Exiguobacterium spp. are facultative anaerobes that have been isolated from a broad range of environments with Exiguobacterium aurantiacum, the type species, being isolated from alkaline potato-processing effluent in 1980.[3] E. aurantiacum has been evaluated for use in bioremediation and as a source for natural pigments.[4][5] Two case studies have associated E. aurantiacum with infections in humans.[6][7]

Exiguobacterium aurantiacum
Scientific classification Edit this classification
Domain: Bacteria
Phylum: Bacillota
Class: Bacilli
Order: Caryophanales
Family: Bacillaceae
Genus: Exiguobacterium
Species:
E. aurantiacum
Binomial name
Exiguobacterium aurantiacum
Collins et al. 1984[1]

Name and classification

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The name Exiguobacterium aurantiacum derives from the Latin exiguus meaning "small" or "slender" and aurantiacus meaning "orange-colored". Exiguobacterium is one of 122 genera within the Bacillaceae family. As of 2024, the Exiguobacterium genus now hosts 19 species recognized by the International Code of Nomenclature of Prokaryotes (ICNP).[8]

History

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The classification, Exiguobacterium aurantiacum, was first assigned in 1983 by Collins et al. after five alkaliphilic bacteria were isolated from potato-processing effluent by Gee et al. in 1980.[9] The first genome was made available in 2014 by the U.S. Department of Energy Joint Genome Institute.[10] The E. aurantiacum DSM 6208 genome is composed of 3.04 Mbp with a GC content of 53%. Of note, the genome was found to have 90 transposases and two cold shock genes.

Description

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Exiguobacterium aurantiacum cells are pleomorphic, ranging from (~3.2 μm) rods in exponential phase to short (~1.2 μm) coccobacilli in stationary phase.[11] Cells are gram-positive, motile, and do not form spores. E. aurantiacum is classified as a facultative anaerobe able to grow on a range of sugars including, but not limited to, glucose, sucrose, and galactose. Aerobically grown colonies are glossy with a honey-orange pigment.

Application

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Exiguobacterium aurantiacum cells contain a bright orange carotenoid pigment that has been evaluated as a potential natural pigment source in industry.[12] E. aurantiacum has also been evaluated for its ability to degrade n-alkanes from diesel. Thus, E. aurantiacum could be used for bioremediation in oil-contaminated environments.[13] Additionally, E. aurantiacum has been found to produce a thermostable protease that functions in alkaline environments.[14]

Opportunistic infections

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Exiguobacterium aurantiacum has been associated with bacteremia in one case study after it was isolated from six human patients with three of the patients being in an immunocompromised state.[15] Prior to this case study, E. aurantiacum was linked to one other infection, a case of periodontitis, in 2003.[16]

References

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  1. ^ "Species: Exiguobacterium aurantiacum". LPSN.DSMZ.de.
  2. ^ Su, Zhaoying; Wang, Shaojing; Yang, Shicheng; Yin, Yujun; Cao, Yunke; Li, Guoqiang; Ma, Ting (January 2022). "Genetic and Comparative Genome Analysis of Exiguobacterium aurantiacum SW-20, a Petroleum-Degrading Bacteria with Salt Tolerance and Heavy Metal-Tolerance Isolated from Produced Water of Changqing Oilfield, China". Microorganisms. 10 (1): 66. doi:10.3390/microorganisms10010066. ISSN 2076-2607. PMC 8779447. PMID 35056515.
  3. ^ Collins, M. D.; Lund, B. M.; Farrow, J. A. E.; Schleifer, K. H. (1983-07-01). "Chemotaxonomic Study of an Alkalophilic Bacterium, Exiguobacterium aurantiacum gen. nov., sp. nov". Microbiology. 129 (7): 2037–2042. doi:10.1099/00221287-129-7-2037. ISSN 1350-0872.
  4. ^ Shatila, Fatima (2013). "Pigment production by Exiguobacterium aurantiacum FH, a novel Lebanese strain" (PDF). International Journal of Current Microbiology and Applied Sciences. 2 (12): 176–191.
  5. ^ Mohanty, Gita; Mukherji, Suparna (2008-04-01). "Biodegradation rate of diesel range n-alkanes by bacterial cultures Exiguobacterium aurantiacum and Burkholderia cepacia". International Biodeterioration & Biodegradation. 61 (3): 240–250. Bibcode:2008IBiBi..61..240M. doi:10.1016/j.ibiod.2007.06.011. ISSN 0964-8305.
  6. ^ Zijnge, V.; Harmsen, H. J. M.; Kleinfelder, J. W.; Van Der Rest, M. E.; Degener, J. E.; Welling, G. W. (February 2003). "Denaturing gradient gel electrophoresis analysis to study bacterial community structure in pockets of periodontitis patients". Oral Microbiology and Immunology. 18 (1): 59–65. doi:10.1034/j.1399-302x.2003.180110.x. ISSN 0902-0055. PMID 12588461.
  7. ^ Pitt, T.L.; Malnick, H.; Shah, J.; Chattaway, M.A.; Keys, C.J.; Cooke, F.J.; Shah, H.N. (September 2007). "Characterisation of Exiguobacterium aurantiacum isolates from blood cultures of six patients". Clinical Microbiology and Infection. 13 (9): 946–948. doi:10.1111/j.1469-0691.2007.01779.x. PMID 17645563.
  8. ^ "Genus: Exiguobacterium". lpsn.dsmz.de. Retrieved 2024-10-07.
  9. ^ Collins, M. D.; Lund, B. M.; Farrow, J. A. E.; Schleifer, K. H. (1983-07-01). "Chemotaxonomic Study of an Alkalophilic Bacterium, Exiguobacterium aurantiacum gen. nov., sp. nov". Microbiology. 129 (7): 2037–2042. doi:10.1099/00221287-129-7-2037. ISSN 1350-0872.
  10. ^ Vishnivetskaya, Tatiana A.; Chauhan, Archana; Layton, Alice C.; Pfiffner, Susan M.; Huntemann, Marcel; Copeland, Alex; Chen, Amy; Kyrpides, Nikos C.; Markowitz, Victor M.; Palaniappan, Krishna; Ivanova, Natalia; Mikhailova, Natalia; Ovchinnikova, Galina; Andersen, Evan W.; Pati, Amrita (2014-10-30). "Draft Genome Sequences of 10 Strains of the Genus Exiguobacterium". Genome Announcements. 2 (5). doi:10.1128/genomeA.01058-14. ISSN 2169-8287. PMC 4200161. PMID 25323723.
  11. ^ Collins, M. D.; Lund, B. M.; Farrow, J. A. E.; Schleifer, K. H. (1983-07-01). "Chemotaxonomic Study of an Alkalophilic Bacterium, Exiguobacterium aurantiacum gen. nov., sp. nov". Microbiology. 129 (7): 2037–2042. doi:10.1099/00221287-129-7-2037. ISSN 1350-0872.
  12. ^ Shatila, Fatima (2013). "Pigment production by Exiguobacterium aurantiacum FH, a novel Lebanese strain" (PDF). International Journal of Current Microbiology and Applied Sciences. 2 (12): 176–191.
  13. ^ Mohanty, Gita; Mukherji, Suparna (2008-04-01). "Biodegradation rate of diesel range n-alkanes by bacterial cultures Exiguobacterium aurantiacum and Burkholderia cepacia". International Biodeterioration & Biodegradation. 61 (3): 240–250. Bibcode:2008IBiBi..61..240M. doi:10.1016/j.ibiod.2007.06.011. ISSN 0964-8305.
  14. ^ Femi-Ola, T. O.; Oladokun, D. O. (March 2012). "Partial purification and characterization of a thermostable alkaline protease from Lactobacillus brevis". Malaysian Journal of Microbiology. doi:10.21161/mjm.28310. ISSN 2231-7538.
  15. ^ Pitt, T.L.; Malnick, H.; Shah, J.; Chattaway, M.A.; Keys, C.J.; Cooke, F.J.; Shah, H.N. (September 2007). "Characterisation of Exiguobacterium aurantiacum isolates from blood cultures of six patients". Clinical Microbiology and Infection. 13 (9): 946–948. doi:10.1111/j.1469-0691.2007.01779.x. PMID 17645563.
  16. ^ Zijnge, V.; Harmsen, H. J. M.; Kleinfelder, J. W.; Van Der Rest, M. E.; Degener, J. E.; Welling, G. W. (February 2003). "Denaturing gradient gel electrophoresis analysis to study bacterial community structure in pockets of periodontitis patients". Oral Microbiology and Immunology. 18 (1): 59–65. doi:10.1034/j.1399-302x.2003.180110.x. ISSN 0902-0055. PMID 12588461.