Piezophile

Last updated

A piezophile (from Greek "piezo-" for pressure and "-phile" for loving) is an organism with optimal growth under high hydrostatic pressure i.e. an organism that has its maximum rate of growth at a hydrostatic pressure equal to or above 10 MPa (= 99 atm = 1,450 psi), when tested over all permissible temperatures. [1] Originally, the term barophile was used for these organisms, but since the prefix "baro-" stands for weight, the term piezophile was given preference. [2] [3] Like all definitions of extremophiles, the definition of piezophiles is anthropocentric, and humans consider that moderate values for hydrostatic pressure are those around 1 atm (= 0.1 MPa = 14.7 psi), whereas those "extreme" pressures are the normal living conditions for those organisms. Hyperpiezophiles are organisms that have their maximum growth rate above 50 MPa (= 493 atm = 7,252 psi). [4]

Contents

Though the high hydrostatic pressure has deleterious effects on organisms growing at atmospheric pressure, these organisms which are solely found at high pressure habitats at deep sea in fact need high pressures for their optimum growth. Often their growth is able to continue at much higher pressures (such as 100MPa) compared to those organisms which normally grow at low pressures. [5]

The first obligate piezophile found was a psychrophilic bacteria called Colwellia marinimaniae strain M-41. [6] [7] It was isolated from a decaying amphipod Hirondellea gigas from the bottom of Mariana Trench. The first thermophilic piezophilic archaea Pyrococcus yayanosii strain CH1 was isolated from the Ashadze site, a deep sea hydrothermal vent. [8] Strain MT-41 has an optimal growth pressure at 70MPa at 2 °C and strain CH1 has a optimal growth pressure at 52MPa at 98 °C. They are unable to grow at pressures lower than or equal to 20MPa, and both can grow at pressures above 100MPa.The current record for highest hydrostatic pressure where growth was observed is 140MPa shown by Colwellia marinimaniae MTCD1 [9] . The term "obligate piezophile" refers to organisms that are unable to grow under lower hydrostatic pressures, such as 0.1 MPa. In contrast, piezotolerant organisms are those that have their maximum rate of growth at a hydrostatic pressure under 10 MPa, but that nevertheless are able to grow at lower rates under higher hydrostatic pressures.

Most of the Earth's biosphere (in terms of volume) is subject to high hydrostatic pressure, and the piezosphere comprises the deep sea (at the depth of 1,000 m and greater) plus the deep subsurface (which can extend up to 5,000 m beneath the seafloor or the continental surface). [4] [10] The deep sea has a mean temperature around 1 to 3 °C, and it is dominated by psychropiezophiles. In contrast, deep subsurface and hydrothermal vents in the seafloor are dominated by thermopiezophiles that prosper in temperatures above 45 °C (113 °F).

Although the study of nutrient acquisition and metabolism within the piezosphere is still in its infancy, it is understood that most of the organic matter present are refractory complex polymers from the eutrophic zone. Both heterotrophic metabolism and autotrophic fixation are present within the piezosphere and additional research suggests significant metabolism of iron-bearing minerals and carbon monoxide. Additional research is required to fully understand and characterize piezosphere metabolism. [11]

Piezophilic adaptations

High pressure has several effects on biological systems. The application of pressure results in equilibrium shifting towards state occupying small volume and it changes intermolecular distances and affects conformations. This also has an effect on the functionality of the cells. Piezophiles employ several mechanisms to adapt themselves to these high hydrostatic pressures. They regulate gene expression according to pressure and also adapt their biomolecules to differences in pressure. [12]

Nucleic acids

High pressure stabilizes hydrogen bonds and stacking interactions of the DNA. Thus it favours the double stranded duplex structure of the DNA. However, to carry out several processes like DNA replication, transcription and translation, the transition to single-strand structure is necessary, which becomes difficult as high pressure increases the melting temperature, Tm. Thus, these processes may face difficulties. [5]

Cell membranes

When pressure increases, the fluidity of the cell membrane is decreased as due to restrictions in volume they change their conformation and packing. This decreases the permeability of the cell membrane to water and different molecules. In response to flucatuation in environment, they change their membrane structures. Piezophilic bacteria do so by varying their acyl chain length, by accumulating unsaturated fatty acids, accumulating specific polar headgroups and branched fatty acids. [13] Piezophilic archaea synthesize archaeol and cadarchaeol-based polar lipids, bipolar tetraether lipids, incorporate cyclopentane rings and increase in unsaturation. [14] [12]

Proteins

The macromolecules bearing the largest effect of pressure are proteins. Just like lipids, they change their conformation and packing to accommodate changes in pressure. This affects their multimeric conformation, stability and also the structure of their catalytic sites, which changes their functionality. [15] In pressure-intolerant species, proteins tend to compact and unfold under high pressures as overall volume is reduced. Piezophilic proteins, however, tend to have less void space and smaller void spaces overall to mitigate compaction and unfolding pressures. There are also changes in the various interactions between amino acids. In general, they are very resistant to pressure. [16] [12]

Enzymes

Due to the functional nature of enzymes, piezophiles must maintain their activity to survive. High pressures tend to favor enzymes with higher flexibility at the cost of lower stability. Additionally, piezophilic enzymes often have high absolute (distinct from temperature or pressure) and relative catalytic activity. This allows the enzymes to maintain sufficient activity even with decreases due to temperature or pressure effects. Furthermore, some piezophilic enzymes have increasing catalytic activity with increasing pressures, though this is not a generalization for all piezophilic enzymes. [16]

Overall effect on cells

As a result of high pressure, several functions may be lost in organisms that are pressure-intolerant. Effects can include loss of flagellar motility, enzyme function, and thus metabolism. It can also lead to cell death due to modifications in the cellular structure. [17] High pressures also can cause an imbalance in oxidation and reduction reactions generating relatively high concentrations of reactive oxygen species (ROS). An increased amount of anti-oxidation genes and proteins are found in piezophiles to combat the ROS as they often cause cellular damage. [3]

See also

Related Research Articles

<span class="mw-page-title-main">Extremophile</span> Organisms capable of living in extreme environments

An extremophile is an organism that is able to live in extreme environments, i.e. environments with conditions approaching or expanding the limits of what known life can adapt to, such as extreme temperature, radiation, salinity, or pH level.

A hyperthermophile is an organism that thrives in extremely hot environments—from 60 °C (140 °F) upwards. An optimal temperature for the existence of hyperthermophiles is often above 80 °C (176 °F). Hyperthermophiles are often within the domain Archaea, although some bacteria are also able to tolerate extreme temperatures. Some of these bacteria are able to live at temperatures greater than 100 °C, deep in the ocean where high pressures increase the boiling point of water. Many hyperthermophiles are also able to withstand other environmental extremes, such as high acidity or high radiation levels. Hyperthermophiles are a subset of extremophiles. Their existence may support the possibility of extraterrestrial life, showing that life can thrive in environmental extremes.

<span class="mw-page-title-main">Psychrophile</span> Organism capable of growing and reproducing in the cold

Psychrophiles or cryophiles are extremophilic organisms that are capable of growth and reproduction in low temperatures, ranging from −20 °C (−4 °F) to 20 °C (68 °F). They are found in places that are permanently cold, such as the polar regions and the deep sea. They can be contrasted with thermophiles, which are organisms that thrive at unusually high temperatures, and mesophiles at intermediate temperatures. Psychrophile is Greek for 'cold-loving', from Ancient Greek ψυχρός (psukhrós) 'cold, frozen'.

<span class="mw-page-title-main">Sphingomyelin</span> Class of chemical compounds

Sphingomyelin is a type of sphingolipid found in animal cell membranes, especially in the membranous myelin sheath that surrounds some nerve cell axons. It usually consists of phosphocholine and ceramide, or a phosphoethanolamine head group; therefore, sphingomyelins can also be classified as sphingophospholipids. In humans, SPH represents ~85% of all sphingolipids, and typically make up 10–20 mol % of plasma membrane lipids.

<span class="mw-page-title-main">Thermoacidophile</span> Microorganisms which live in water with high temperature and high acidity

A thermoacidophile is an extremophilic microorganism that is both thermophilic and acidophilic; i.e., it can grow under conditions of high temperature and low pH. The large majority of thermoacidophiles are archaea or bacteria, though occasional eukaryotic examples have been reported. Thermoacidophiles can be found in hot springs and solfataric environments, within deep sea vents, or in other environments of geothermal activity. They also occur in polluted environments, such as in acid mine drainage.

<i>Pyrococcus furiosus</i> Species of archaeon

Pyrococcus furiosus is a heterotrophic, strictly anaerobic, extremophilic, model species of archaea. It is classified as a hyperthermophile because it thrives best under extremely high temperatures, and is notable for having an optimum growth temperature of 100 °C. P. furiosus belongs to the Pyrococcus genus, most commonly found in extreme environmental conditions of hydrothermal vents. It is one of the few prokaryotic organisms that has enzymes containing tungsten, an element rarely found in biological molecules.

Microbial metabolism is the means by which a microbe obtains the energy and nutrients it needs to live and reproduce. Microbes use many different types of metabolic strategies and species can often be differentiated from each other based on metabolic characteristics. The specific metabolic properties of a microbe are the major factors in determining that microbe's ecological niche, and often allow for that microbe to be useful in industrial processes or responsible for biogeochemical cycles.

<span class="mw-page-title-main">Acyl-(acyl-carrier-protein) desaturase</span> Class of enzymes

In enzymology, an acyl-[acyl-carrier-protein] desaturase (EC 1.14.19.2) is an enzyme that catalyzes the chemical reaction

<i>Photobacterium profundum</i> Species of bacterium

Photobacterium profundum is a deep sea Gammaproteobacterium, belonging to the family Vibrionaceae and genus Photobacterium. Like other members of this genus, P. profundum is a marine organism and has two circular chromosomes. P. profundum is a gram-negative rod with the ability for growth at temperatures from 0 °C to 25 °C and pressures from 0.1 MPa to 70 MPa depending on the strain. It has a requirement for salt, is able to metabolise a wide range of simple and complex carbohydrates and has two flagella systems. Cells are rod shape, 2-4μm long and 0.8-1.0μm wide, with a single unsheathed flagella. This bacterium was originally isolated in 1986 from the Sulu Sea and there are currently 4 cultured wild-type strains of P. profundum,.

<span class="mw-page-title-main">Archaea</span> Domain of single-celled organisms

Archaea is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria, but this term has fallen out of use.

Obcells are hypothetical proto-organisms or the earliest form of life. The term was first proposed by Thomas Cavalier-Smith in 2001. According to Cavalier-Smith's theory for the origin of the first cell, two cup-shaped obcells or hemicells fused to make a protocell with double-lipid layer envelope, internal genome and ribosomes, protocytosol, and periplasm.

Pascalization, bridgmanization, high pressure processing (HPP) or high hydrostatic pressure (HHP) processing is a method of preserving and sterilizing food, in which a product is processed under very high pressure, leading to the inactivation of certain microorganisms and enzymes in the food. HPP has a limited effect on covalent bonds within the food product, thus maintaining both the sensory and nutritional aspects of the product. The technique was named after Blaise Pascal, a 17th century French scientist whose work included detailing the effects of pressure on fluids. During pascalization, more than 50,000 pounds per square inch may be applied for approximately fifteen minutes, leading to the inactivation of yeast, mold, vegetative bacteria, and some viruses and parasites. Pascalization is also known as bridgmanization, named for physicist Percy Williams Bridgman.

Microbes can be damaged or killed by elements of their physical environment such as temperature, radiation, or exposure to chemicals; these effects can be exploited in efforts to control pathogens, often for the purpose of food safety.

Shewanella violacea DSS12 is a gram-negative bacterium located in marine sediment in the Ryukyu Trench at a depth of 5,110m. The first description of this organism was published in 1998 by Japanese microbiologists Yuichi Nogi, Chiaki Kato, and Koki Horikoshi, who named the species after its violet appearance when it is grown on Marine Agar 2216 Plates.

Methanococcoides burtonii is a methylotrophic methanogenic archaeon first isolated from Ace Lake, Antarctica. Its type strain is DSM 6242.

Persephonella marina is a Gram-negative, rod shaped bacteria that is a member of the Aquificota phylum. Stemming from Greek, the name Persephonella is based upon the mythological goddess Persephone. Marina stems from a Latin origin, meaning "belonging to the sea". It is a thermophile with an obligate chemolithoautotrophic metabolism. Growth of P. marina can occur in pairs or individually, but is rarely seen aggregating in large groups. The organism resides on sulfidic chimneys in the deep ocean and has never been documented as a pathogen.

Thermococcus barophilus is a piezophilic and hyperthermophilic archaeon isolated from a deep-sea hydrothermal vent. It is anaerobic and sulfur-metabolising, with type strain MPT.

Marinitoga piezophila is a species of rod-shaped, thermo-piezophilic bacteria. It is, anaerobic, chemo-organotrophic, sulfur-reducing, motile, have a mean length of 1-1.5 micrometres and stains Gram-negative. The type strain is KA3T.

Colwellia marinimaniae is a hyperpiezophilic bacterium from the genus Colwellia which has been isolated from deep regions of the Mariana Trench. It is, so far, the most piezophilic organism yet described, with an optimal growth pressure of 120 MPa.

<span class="mw-page-title-main">Hydrothermal vent microbial communities</span> Undersea unicellular organisms

The hydrothermal vent microbial community includes all unicellular organisms that live and reproduce in a chemically distinct area around hydrothermal vents. These include organisms in the microbial mat, free floating cells, or bacteria in an endosymbiotic relationship with animals. Chemolithoautotrophic bacteria derive nutrients and energy from the geological activity at Hydrothermal vents to fix carbon into organic forms. Viruses are also a part of the hydrothermal vent microbial community and their influence on the microbial ecology in these ecosystems is a burgeoning field of research.

References

  1. ↑ Yayanos, A Aristides (2008-12-15). "Piezophiles". In John Wiley & Sons, Ltd (ed.). Encyclopedia of Life Sciences. John Wiley & Sons, Ltd. pp. a0000341.pub2. doi:10.1002/9780470015902.a0000341.pub2. ISBN   9780470016176.
  2. ↑ Yayanos, A A (October 1995). "Microbiology To 10,500 Meters in the Deep Sea". Annual Review of Microbiology. 49 (1): 777–805. doi:10.1146/annurev.mi.49.100195.004021. ISSN   0066-4227. PMID   8561479.
  3. 1 2 Zhang, Yu; Li, Xuegong; Bartlett, Douglas H; Xiao, Xiang (2015-06-01). "Current developments in marine microbiology: high-pressure biotechnology and the genetic engineering of piezophiles". Current Opinion in Biotechnology. Environmental biotechnology • Energy biotechnology. 33: 157–164. doi:10.1016/j.copbio.2015.02.013. ISSN   0958-1669. PMID   25776196.
  4. 1 2 Fang, Jiasong; Zhang, Li; Bazylinski, Dennis A. (September 2010). "Deep-sea piezosphere and piezophiles: geomicrobiology and biogeochemistry". Trends in Microbiology. 18 (9): 413–422. doi:10.1016/j.tim.2010.06.006. PMID   20663673.
  5. 1 2 Oger, Philippe M.; Jebbar, Mohamed (2010-12-01). "The many ways of coping with pressure". Research in Microbiology. 161 (10): 799–809. doi: 10.1016/j.resmic.2010.09.017 . ISSN   0923-2508. PMID   21035541. S2CID   7197287.
  6. ↑ Yayanos, A. A.; Dietz, A. S.; Van Boxtel, R. (August 1981). "Obligately barophilic bacterium from the Mariana trench". Proceedings of the National Academy of Sciences of the United States of America. 78 (8): 5212–5215. Bibcode:1981PNAS...78.5212Y. doi: 10.1073/pnas.78.8.5212 . ISSN   0027-8424. PMC   320377 . PMID   6946468.
  7. ↑ Peoples, Logan M.; Kyaw, Than S.; Ugalde, Juan A.; Mullane, Kelli K.; Chastain, Roger A.; Yayanos, A. Aristides; Kusube, Masataka; Methé, Barbara A.; Bartlett, Douglas H. (2020-10-06). "Distinctive gene and protein characteristics of extremely piezophilic Colwellia". BMC Genomics. 21 (1): 692. doi:10.1186/s12864-020-07102-y. ISSN   1471-2164. PMC   7542103 . PMID   33023469.{{cite journal}}: CS1 maint: unflagged free DOI (link)
  8. ↑ Zeng, Xiang; Birrien, Jean-Louis; Fouquet, Yves; Cherkashov, Georgy; Jebbar, Mohamed; Querellou, Joël; Oger, Philippe; Cambon-Bonavita, Marie-Anne; Xiao, Xiang; Prieur, Daniel (July 2009). "Pyrococcus CH1, an obligate piezophilic hyperthermophile: extending the upper pressure-temperature limits for life". The ISME Journal. 3 (7): 873–876. doi: 10.1038/ismej.2009.21 . ISSN   1751-7370. PMID   19295639. S2CID   1106209.
  9. ↑ Kusube, Masataka; Kyaw, Than S.; Tanikawa, Kumiko; Chastain, Roger A.; Hardy, Kevin M.; Cameron, James; Bartlett, Douglas H. (2017-04-01). "Colwellia marinimaniae sp. nov., a hyperpiezophilic species isolated from an amphipod within the Challenger Deep, Mariana Trench". International Journal of Systematic and Evolutionary Microbiology. 67 (4): 824–831. doi: 10.1099/ijsem.0.001671 . ISSN   1466-5026. PMID   27902293.
  10. ↑ Kieft, Thomas L. (2016), "Microbiology of the Deep Continental Biosphere", in Hurst, Christon J. (ed.), Their World: A Diversity of Microbial Environments, Advances in Environmental Microbiology, vol. 1, Springer International Publishing, pp. 225–249, doi:10.1007/978-3-319-28071-4_6, ISBN   9783319280691
  11. ↑ Fang, Jiasong; Zhang, Li; Bazylinski, Dennis A. (2010-09-01). "Deep-sea piezosphere and piezophiles: geomicrobiology and biogeochemistry". Trends in Microbiology. 18 (9): 413–422. doi:10.1016/j.tim.2010.06.006. ISSN   0966-842X. PMID   20663673.
  12. 1 2 3 Oger, Philippe M.; Jebbar, Mohamed (December 2010). "The many ways of coping with pressure". Research in Microbiology. 161 (10): 799–809. doi: 10.1016/j.resmic.2010.09.017 . ISSN   1769-7123. PMID   21035541. S2CID   7197287.
  13. ↑ Tamby, Anandi; Sinninghe-Damste, Jaap; Villanueva, Laura. "Microbial membrane lipid adaptations to high hydrostatic pressure in the marine environment". Frontiers in Molecular Biosciences. Retrieved 23 October 2023.
  14. ↑ Winter, Roland; Jeworrek, Christoph (2009-08-18). "Effect of pressure on membranes". Soft Matter. 5 (17): 3157–3173. Bibcode:2009SMat....5.3157W. doi:10.1039/B901690B. ISSN   1744-6848.
  15. ↑ Balny, Claude; Masson, Patrick; Heremans, Karel (March 2002). "High pressure effects on biological macromolecules: from structural changes to alteration of cellular processes". Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology. 1595 (1–2): 3–10. doi:10.1016/s0167-4838(01)00331-4. ISSN   0167-4838. PMID   11983383.
  16. 1 2 Ichiye, Toshiko (2018-12-01). "Enzymes from piezophiles". Seminars in Cell & Developmental Biology. SI: Antigen presentation. 84: 138–146. doi:10.1016/j.semcdb.2018.01.004. ISSN   1084-9521. PMC   6050138 . PMID   29331641.
  17. ↑ Abe, F.; Horikoshi, K. (March 2001). "The biotechnological potential of piezophiles". Trends in Biotechnology. 19 (3): 102–108. doi:10.1016/s0167-7799(00)01539-0. ISSN   0167-7799. PMID   11179803.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.