Halocin

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Halocins are bacteriocins produced by halophilic Archaea [1] [2] and a type of archaeocin. [3]

Since their discovery in 1982, [4] halocins have been demonstrated to be diverse in a similar ways as the other bacteriocins. [5] [6] [7] Some are large proteins, some small polypeptides (microhalocins). This diversity is surprising for a number of reasons, including the original presumptions that Archaea, particularly extremophiles, live at relatively low densities under conditions that may not require antagonistic behavior.

The genetics, [8] [9] [10] [11] [12] mechanism of production [13] [14] and mechanism of action [15] [16] [17] [18] of the halocins have been studied, but not exhaustively. The ecology of the halocins [19] [20] [21] has been investigated as well. One interesting observation is that the halocins are active across the major divisions of archaea, [22] thus violating the dogma that they should be most effective against the most closely related strains.

Halocins are particularly interesting because of the way the pore-forming bacteriocins have been used to probe cell membrane structure and the production and maintenance of energetic ion gradients across the membrane. The halophiles live at such extreme ion concentrations that they represent a set of unusual solutions and adaptations with regard to their energetic gradients. The ability to use native halocins to study these gradients provides a motivation for their characterization.

They may have a role in human medicine. [23] [24]

They are also found in many of the type species that are used to learn about halophiles in general. [25]

Like other bacteriocins, the halocins are under investigation as antimicrobials for use in controlling spoilage during industrial processes; in this case, leather production. [26]

Because the literature about halocins is relatively circumscribed, it can be exhaustively cited. Several times they have been addressed in book chapters. [3] [27] [28] [29]

BACTIBASE [30] [31] database is an open-access database for bacteriocins including halocins (view complete list).

Related Research Articles

A halophile is an extremophile that thrives in high salt concentrations. In chemical terms, halophile refers to a Lewis acidic species that has some ability to extract halides from other chemical species.

<i>Halobacterium</i> Genus of archaea

Halobacterium is a genus in the family Halobacteriaceae.

Halobacteriaceae is a family in the order Halobacteriales and the domain Archaea. Halobacteriaceae represent a large part of halophilic Archaea, along with members in two other methanogenic families, Methanosarcinaceae and Methanocalculaceae. The family consists of many diverse genera that can survive extreme environmental niches. Most commonly, Halobacteriaceae are found in hypersaline lakes and can even tolerate sites polluted by heavy metals. They include neutrophiles, acidophiles, alkaliphiles, and there have even been psychrotolerant species discovered. Some members have been known to live aerobically, as well as anaerobically, and they come in many different morphologies. These diverse morphologies include rods in genus Halobacterium, cocci in Halococcus, flattened discs or cups in Haloferax, and other shapes ranging from flattened triangles in Haloarcula to squares in Haloquadratum, and Natronorubrum. Most species of Halobacteriaceae are best known for their high salt tolerance and red-pink pigmented members, but there are also non-pigmented species and those that require moderate salt conditions. Some species of Halobacteriaceae have been shown to exhibit phosphorus solubilizing activities that contribute to phosphorus cycling in hypersaline environments. Techniques such as 16S rRNA analysis and DNA-DNA hybridization have been major contributors to taxonomic classification in Halobacteriaceae, partly due to the difficulty in culturing halophilic Archaea.

<span class="mw-page-title-main">Halobacteriales</span> Order of archaea

Halobacteriales are an order of the Halobacteria, found in water saturated or nearly saturated with salt. They are also called halophiles, though this name is also used for other organisms which live in somewhat less concentrated salt water. They are common in most environments where large amounts of salt, moisture, and organic material are available. Large blooms appear reddish, from the pigment bacteriorhodopsin. This pigment is used to absorb light, which provides energy to create ATP. Halobacteria also possess a second pigment, halorhodopsin, which pumps in chloride ions in response to photons, creating a voltage gradient and assisting in the production of energy from light. The process is unrelated to other forms of photosynthesis involving electron transport; however, and halobacteria are incapable of fixing carbon from carbon dioxide.

<span class="mw-page-title-main">Haloarchaea</span> Class of salt-tolerant archaea

Haloarchaea are a class of the Euryarchaeota, found in water saturated or nearly saturated with salt. Halobacteria are now recognized as archaea rather than bacteria and are one of the largest groups. The name 'halobacteria' was assigned to this group of organisms before the existence of the domain Archaea was realized, and while valid according to taxonomic rules, should be updated. Halophilic archaea are generally referred to as haloarchaea to distinguish them from halophilic bacteria.

<i>Halobacterium salinarum</i> Species of archaeon

Halobacterium salinarum, formerly known as Halobacterium cutirubrum or Halobacterium halobium, is an extremely halophilic marine obligate aerobic archaeon. Despite its name, this is not a bacterium, but a member of the domain Archaea. It is found in salted fish, hides, hypersaline lakes, and salterns. As these salterns reach the minimum salinity limits for extreme halophiles, their waters become purple or reddish color due to the high densities of halophilic Archaea. H. salinarum has also been found in high-salt food such as salt pork, marine fish, and sausages. The ability of H. salinarum to survive at such high salt concentrations has led to its classification as an extremophile.

<i>Haloarcula</i> Genus of archaea

Haloarcula is a genus of extreme halophilic Archaea in the class of Halobactaria.

<i>Haloferax</i> Genus of archaea

In taxonomy, Haloferax is a genus of the Haloferacaceae.

Halorubrum is a genus in the family Halorubraceae. Halorubrum species areusually halophilic and can be found in waters with high salt concentration such as the Dead Sea or Lake Zabuye.

In taxonomy, Natrialba is a genus of the Natrialbaceae. The genus consists of many diverse species that can survive extreme environmental niches, especially they are capable to live in the waters saturated or nearly saturated with salt (halophiles). They have certain adaptations to live within their salty environments. For example, their cellular machinery is adapted to high salt concentrations by having charged amino acids on their surfaces, allowing the cell to keep its water molecules around these components. The osmotic pressure and these amino acids help to control the amount of salt within the cell.

Archaeocin is the name given to a new type of potentially useful antibiotic that is derived from the Archaea group of organisms. Eight archaeocins have been partially or fully characterized, but hundreds of archaeocins are believed to exist, especially within the haloarchaea. Production of these archaeal proteinaceous antimicrobials is a nearly universal feature of the rod-shaped haloarchaea.

GvpA is a gas vesicle structural protein found in different phyla of bacteria and archaea for example in Halobacterium salinarum or Haloferax mediterranei. Gas vesicles are small, hollow, gas filled protein structures found in several cyanobacterial and archaebacterial microorganisms. They allow the positioning of the bacteria at a favourable depth for growth.

<i>Haloferax volcanii</i> Species of Halobacteria

Haloferax volcanii is a species of organism in the genus Haloferax in the Archaea.

<i>Haloquadratum walsbyi</i> Species of archaeon

Haloquadratum walsbyi is of the genus Haloquadratum, within the archaea domain known for its square halophilic nature. First discovered in a brine pool in the Sinai peninsula of Egypt, H. walsbyi is noted for its flat, square-shaped cells, and its unusual ability to survive in aqueous environments with high concentrations of sodium chloride and magnesium chloride. The species' genus name Haloquadratum translates from Greek and Latin as "salt square". This archaean is also commonly referred to as "Walsby's Square Bacterium" because of its identifying square shape which makes it unique. In accordance with its name, Haloquadratum walsbyi are most abundantly observed in salty environments.

Halobacterium noricense is a halophilic, rod-shaped microorganism that thrives in environments with salt levels near saturation. Despite the implication of the name, Halobacterium is actually a genus of archaea, not bacteria. H. noricense can be isolated from environments with high salinity such as the Dead Sea and the Great Salt Lake in Utah. Members of the Halobacterium genus are excellent model organisms for DNA replication and transcription due to the stability of their proteins and polymerases when exposed to high temperatures. To be classified in the genus Halobacterium, a microorganism must exhibit a membrane composition consisting of ether-linked phosphoglycerides and glycolipids.

<span class="mw-page-title-main">Gas vesicle</span>

Gas vesicles, also known as gas vacuoles, are nanocompartments in certain prokaryotic organisms, which help in buoyancy. Gas vesicles are composed entirely of protein; no lipids or carbohydrates have been detected.

<span class="mw-page-title-main">Shiladitya DasSarma</span>

Shiladitya DasSarma is a molecular biologist well-known for contributions to the biology of halophilic and extremophilic microorganisms. He is a Professor in the University of Maryland Baltimore. He earned a PhD degree in biochemistry from the Massachusetts Institute of Technology and a BS degree in chemistry from Indiana University Bloomington. Prior to taking a faculty position, he conducted research at the Massachusetts General Hospital, Harvard Medical School, and Pasteur Institute, Paris.

<span class="mw-page-title-main">Haloferacaceae</span> Family of bacteria

Haloferacaceae is a family of halophilic, chemoorganotrophic or heterotrophic archaea within the order Haloferacales. The type genus of this family is Haloferax. Its biochemical characteristics are the same as the order Haloferacales.

<i>Haloferax mediterranei</i> Species of bacterium

Haloferax mediterranei is a species of archaea in the family Haloferacaceae.

Haloferacales is an order of halophilic, chemoorganotrophic or heterotrophic archaea within the class Haloarchaea. The type genus of this order is Haloferax.

References

  1. ↑ Li Y, Xiang H, Tan H (2002). "[Halocin: protein antibiotics produced by extremely halophilic archaea]". Wei Sheng Wu Xue Bao (in Chinese). 42 (4): 502–5. PMID   12557560.
  2. ↑ O'Connor EM, Shand RF (2002). "Halocins and sulfolobicins: the emerging story of archaeal protein and peptide antibiotics". Journal of Industrial Microbiology & Biotechnology . 28 (1): 23–31. doi: 10.1038/sj/jim/7000190 . PMID   11938468. S2CID   16583426.
  3. 1 2 Shand RF, Leyva KJ (2008). "Archaeal Antimicrobials: An Undiscovered Country". Archaea: New Models for Prokaryotic Biology. Caister Academic Press. ISBN   978-1-904455-27-1.
  4. ↑ Rodríguez-Valera F, Juez G, Kushner DJ (1982). "Halocins: salt-dependent bacteriocins produced by extremely halophilic rod". Canadian Journal of Microbiology. 28: 151–154. doi:10.1139/m82-019.
  5. ↑ Torreblanca M, Meseguer I, Rodríguez-Valera F (1989). "Halocin H6, a bacteriocin from Haloferax gibbonsii". Journal of General Microbiology. 135 (10): 2655–2661. doi: 10.1099/00221287-135-10-2655 .
  6. ↑ Price LB, Shand RF (2000). "Halocin S8: a 36-Amino-Acid Microhalocin from the Haloarchaeal Strain S8a". Journal of Bacteriology . 182 (17): 4951–8. doi:10.1128/JB.182.17.4951-4958.2000. PMC   111376 . PMID   10940040.
  7. ↑ Platas G, Meseguer I, Amils R (2002). "Purification and biological characterization of halocin H1 from Haloferax mediterranei M2a". International Microbiology . 5 (1): 15–9. doi:10.1007/s10123-002-0053-4. PMID   12102231. S2CID   45501770.
  8. ↑ Mei SS, Li Y, Lu QH, Xiang H (2006). "[Cloning and analysis of genes in the halocin C8 gene cluster]". Wei Sheng Wu Xue Bao (in Chinese). 46 (2): 318–22. PMID   16736600.
  9. ↑ Sun C, Li Y, Mei S, Lu Q, Zhou L, Xiang H (2005). "A single gene directs both production and immunity of halocin C8 in a haloarchaeal strain AS7092". Molecular Microbiology . 57 (2): 537–49. doi: 10.1111/j.1365-2958.2005.04705.x . PMID   15978083.
  10. ↑ Perez, AM (2000). Growth physiology of Haloferax mediterranei R4 and purification of halocin H4. Flagstaff, Arizona: Northern Arizona University. pp. Masters Thesis.
  11. ↑ Cheung J, Danna KJ, O'Connor EM, Price LB, Shand RF (1997). "Isolation, sequence, and expression of the gene encoding halocin H4, a bacteriocin from the halophilic archaeon Haloferax mediterranei R4". Journal of Bacteriology . 179 (2): 548–51. doi:10.1128/jb.179.2.548-551.1997. PMC   178729 . PMID   8990311.
  12. ↑ Platas G, Meseguer I, Amils R (1996). "Optimization of the production of a bacteriocin from Haloferax mediterranei Xia3". Microbiología . 12 (1): 75–84. PMID   9019137.
  13. ↑ Meseguer I, Rodríguez-Valera F (1985). "Production and purification of halocin H4". FEMS Microbiology Letters. 28 (2): 177–182. doi: 10.1111/j.1574-6968.1985.tb00787.x .
  14. ↑ Li Y, Xiang H, Liu J, Zhou M, Tan H (2003). "Purification and biological characterization of halocin C8, a novel peptide antibiotic from Halobacterium strain AS7092". Extremophiles . 7 (5): 401–7. doi:10.1007/s00792-003-0335-6. PMID   12811620. S2CID   32609554.
  15. ↑ Platas G (1995). Caracterizacíon de la actividad antimicrobiana de la haloarquea Haloferax mediterranei Xia3. Madrid, Spain: Universidad Autónoma de Madrid. pp. Doctoral Thesis.
  16. ↑ Meseguer I, Torreblanca M, Konishi T (1995). "Specific inhibition of the halobacterial Na+/H+ antiporter by halocin H6". Journal of Biological Chemistry . 270 (12): 6450–5. doi: 10.1074/jbc.270.12.6450 . PMID   7896778.
  17. ↑ Meseguer I, Rodríguez-Valera F (1986). "Effect of halocin H4 on cells of Halobacterium halobium". Journal of General Microbiology. 132 (11): 3061–3068. doi: 10.1099/00221287-132-11-3061 .
  18. ↑ Girones F, Minagawa A, Hatano Y, Torreblanca M, Meseguer I, Sanchez M, Konishi T (2001). "Protein-protein interaction between halocin H7 and halobacterial membrane protein". Nippon Yakugakkai Nenkai Koen Yoshishu. 121 (4): 116.
  19. ↑ Kis-Papo T, Oren A (2000). "Halocins: are they involved in the competition between halobacteria in saltern ponds?". Extremophiles . 4 (1): 35–41. doi:10.1007/s007920050005. PMID   10741835. S2CID   24584604.
  20. ↑ Meseguer I, Rodríguez-Valera F, Ventosa A (1986). "Antagonistic interactions among halobacteria due to halocin production". FEMS Microbiology Letters. 36 (2–3): 177–182. doi: 10.1111/j.1574-6968.1986.tb01691.x .
  21. ↑ Oren A (1994). "The ecology of the halophilic archaea". FEMS Microbiology Reviews. 13 (4): 415–440. doi: 10.1111/j.1574-6976.1994.tb00060.x .
  22. ↑ Haseltine C, Hill T, Montalvo-Rodriguez R, Kemper SK, Shand RF, Blum P (2001). "Secreted Euryarchaeal Microhalocins Kill Hyperthermophilic Crenarchaea". Journal of Bacteriology . 183 (1): 287–91. doi:10.1128/JB.183.1.287-291.2001. PMC   94877 . PMID   11114928.
  23. ↑ Alberola A, Meseguer I, Torreblanca M, Moya A, Sancho S, Polo B, Soria B, Such L (1998). "Halocin H7 decreases infarct size and ectopic beats after mycardial reperfusion in dogs". Journal of Physiology.
  24. ↑ Lequerica JL, O'Connor JE, Such L, Alberola A, Meseguer I, Dolz M, Torreblanca M, Moya A, Colom F, Soria B (2006). "A halocin acting on Na+/H+ exchanger of haloarchaea as a new type of inhibitor in NHE of mammals". Journal of Physiology and Biochemistry . 62 (4): 253–62. doi:10.1007/BF03165754. PMID   17615951. S2CID   8822522.
  25. ↑ Soppa J, Oesterhelt D (1989). "Halobacterium sp. GRB: a species to work with!?". Canadian Journal of Microbiology . 35 (1): 205–9. doi:10.1139/m89-032. PMID   2720494.
  26. ↑ Birbir M, Eryilmaz S, Ogan A (2004). "Prevention of halophilic microbial damage on brine cured hides by extremely halophilic halocin producer strains". Journal of the Society of Leather Technologists and Chemists. 88 (3): 99–104.
  27. ↑ Rdest U, Sturm M (1987). "Bacteriocins from halobacteria". In Burgess R (ed.). Protein Purification: Micro to Macro. New York, New York: Alan R. Liss. pp. 271–278.
  28. ↑ Shand RF, Perez AM (1999). "Haloarchaeal growth physiology". In Seckback J (ed.). Enigmatic Organisms and Life in Extreme Environments. Dordrecht, The Netherlands: Kluwer Acadademic Press. pp. 413–424.
  29. ↑ Shand RF, Price LB, O'Connor EM (1999). "Halocins: protein antibiotics from hypersaline environments". In Oren A (ed.). Microbiology and Biogeochemistry of Hypersaline Environments. Boca Raton, FL: CRC Press. pp. 295–306.
  30. ↑ Hammami R, Zouhir A, Ben Hamida J, Fliss I (2007). "BACTIBASE: a new web-accessible database for bacteriocin characterization". BMC Microbiology. 7: 89. doi: 10.1186/1471-2180-7-89 . PMC   2211298 . PMID   17941971.
  31. ↑ Hammami R, Zouhir A, Le Lay C, Ben Hamida J, Fliss I (2010). "BACTIBASE second release: a database and tool platform for bacteriocin characterization". BMC Microbiology. 10: 22. doi: 10.1186/1471-2180-10-22 . PMC   2824694 . PMID   20105292.
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