Trichodesmium

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Trichodesmium
Trichodesmium bloom off Great Barrier Reef 2014-03-07 19-59.jpg
Trichodesmium bloom off the Great Barrier Reef
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Bacteria
Phylum: Cyanobacteria
Class: Cyanophyceae
Order: Oscillatoriales
Family: Microcoleaceae
Genus: Trichodesmium
Ehrenberg ex Gomont, 1892
Species

Trichodesmium contortum
Trichodesmium erythraeum
Trichodesmium hildebrandtii
Trichodesmium radians
Trichodesmium tenue
Trichodesmium thiebautii

Contents

Illustration Simplefilaments022 Trichodesmium.jpg
Illustration

Trichodesmium, also called sea sawdust, is a genus of filamentous cyanobacteria. They are found in nutrient poor tropical and subtropical ocean waters (particularly around Australia and in the Red Sea, where they were first described by Captain Cook). Trichodesmium is a diazotroph; that is, it fixes atmospheric nitrogen into ammonium, a nutrient used by other organisms. Trichodesmium is thought to fix nitrogen on such a scale that it accounts for almost half of the nitrogen fixation in marine systems globally. [1] Trichodesmium is the only known diazotroph able to fix nitrogen in daylight under aerobic conditions without the use of heterocysts. [2]

Trichodesmium can live as individual filaments, with tens to hundreds of cells strung together, or in colonies consisting of tens to hundreds of filaments clustered together. [3] These colonies are visible to the naked eye and sometimes form blooms, which can be extensive on surface waters. These large blooms led to widespread recognition as "sea sawdust/straw"; in fact, the Red Sea gets most of its eponymous colouration from the corresponding pigment in Trichodesmium erythraeum . Colonies of Trichodesmium provide a pseudobenthic substrate for many small oceanic organisms including bacteria, diatoms, dinoflagellates, protozoa, and copepods (which are its primary predator); in this way, the genus can support complex microenvironments.

Species

Trichodesmium erythraeum – described by Ehrenberg in 1830. [4] T. erythraeum is the species responsible for discoloring the Red Sea during blooms. This is the only sequenced genome in the genus thus far and is the focus of most laboratory studies (Trichodesmium IMS 101).

Trichodesmium thiebautii – Described by Gomont in 1892. [5]

Trichodesmium hildebrantii – Described by Gomont in 1892. [5]

Trichodesmium contortum – Described by Wille in 1904. [6]

Trichodesmium tenue – Described by Wille in 1904. [6]

Trichodesmium radians – Described by Wille in 1904. [6]

Cell structure

Like most cyanobacteria, Trichodesmium has a gram negative cell wall. However, unlike other aerobic diazotrophs, heterocysts (structures found in cyanobacteria which protect nitrogenase from oxygenation) are lacking in Trichodesmium. This is a unique characteristic among aerobic diazotrophs which fix nitrogen in daylight. Photosynthesis occurs using phycoerythrin – light-harvesting phycobiliprotein which is normally found within heterocysts in other diazotrophs.

Instead of having localized stacks of thylakoids, Trichodesmium has unstacked thylakoids found throughout the cell. Trichodesmium is highly vacuolated and the content and size of the vacuoles shows diurnal variation. Large gas vesicles (either along the periphery as seen in T. erythaeum or found distributed throughout the cell as seen in T. thiebautii) allow Trichodesmium to regulate buoyancy in the water column. These gas vesicles can withstand high pressure, presumably those up to 100–200 m in the water column, allowing Trichodesmium to move vertically through the water column harvesting nutrients. [7]

Nitrogen fixation

N2 is the most abundant chemical in the atmosphere. However, diatomic nitrogen is not usable for most biological processes. Nitrogen fixation is the process of converting atmospheric diatomic nitrogen into biologically usable forms of nitrogen such as ammonium and nitrogen oxides. This process requires a substantial amount of energy (in the form of ATP) in order to break the triple bond between the nitrogen atoms. [8]

Trichodesmium is the major diazotroph in marine pelagic systems [7] and is an important source of "new" nitrogen in the nutrient poor waters it inhabits. It has been estimated that the global input of nitrogen fixation by Trichodesmium is approximately 60–80 Tg (megatonnes or 1012 grams) N per year. [9] Nitrogen fixation in Trichodesmium is unique among diazotrophs because the process occurs concurrently with oxygen production (via photosynthesis [2] ). In other cyanobacteria, N2 and CO2 reduction are separated either in space (using heterocysts to protect the sensitive nitrogenase enzyme from oxygen) or time. However, Trichodesmium lacks heterocysts and nitrogen fixation peaks during daylight hours (following a diel flux initiated in the morning, reaching a maximum fixation rate midday, and ceasing activity at night). [7] Since the first realization of this enigma, Trichodesmium has been the focus of many studies to try and discover how nitrogen fixation is able to occur in the presence of oxygen production without any apparent structure separating the two processes.

Inhibitor studies even revealed that photosystem II activity is essential for nitrogen fixation in this organism. All this may seem contradictory at first glance, because the enzyme responsible for nitrogen fixation, nitrogenase, is irreversibly inhibited by oxygen. However, Trichodesmium utilises photosynthesis for nitrogen fixation by carrying out the Mehler reaction, during which the oxygen produced by PSII is reduced again after PSI. This regulation of photosynthesis for nitrogen fixation involves rapidly reversible coupling of their light-harvesting antenna, the phycobilisomes, with PSI and PSII. [10]

Ecology

Trichodesmium erythraeum bloom, between Vanuatu and New Caledonia, SW Pacific Ocean. Trichodesmium bloom, SW Pacific.jpg
Trichodesmium erythraeum bloom, between Vanuatu and New Caledonia, SW Pacific Ocean.
Examples of Trichodesmium colonies sorted into morphological classes (A) radial puffs, (B) non-radial puffs, (C) tufts. Trichodesmium colonies sorted into the morphological classes.jpg
Examples of Trichodesmium colonies sorted into morphological classes
(A) radial puffs, (B) non-radial puffs, (C) tufts.
Colonies of marine cyanobacteria Trichodesmium interact with other bacteria to acquire iron from dust a. The N2-fixing Trichodesmium spp., which commonly occurs in tropical and sub-tropical waters, is of large environmental significance in fertilizing the ocean with important nutrients. b. Trichodesmium can establish massive blooms in nutrient poor ocean regions with high dust deposition, partly due to their unique ability to capture dust, center it, and subsequently dissolve it. c. Proposed dust-bound Fe acquisition pathway: Bacteria residing within the colonies produce siderophores (C-I) that react with the dust particles in the colony core and generate dissolved Fe (C-II). This dissolved Fe, complexed by siderophores, is then acquired by both Trichodesmium and its resident bacteria (C-III), resulting in a mutual benefit to both partners of the consortium. Trichodesmium interact with bacteria to acquire iron from dust.webp
Colonies of marine cyanobacteria Trichodesmium
interact with other bacteria to acquire iron from dust
a. The N2-fixing Trichodesmium spp., which commonly occurs in tropical and sub-tropical waters, is of large environmental significance in fertilizing the ocean with important nutrients.
b. Trichodesmium can establish massive blooms in nutrient poor ocean regions with high dust deposition, partly due to their unique ability to capture dust, center it, and subsequently dissolve it.
c. Proposed dust-bound Fe acquisition pathway: Bacteria residing within the colonies produce siderophores (C-I) that react with the dust particles in the colony core and generate dissolved Fe (C-II). This dissolved Fe, complexed by siderophores, is then acquired by both Trichodesmium and its resident bacteria (C-III), resulting in a mutual benefit to both partners of the consortium.

Trichodesmium is found in oligotrophic waters, often when waters are calm and the mixed layer depth is shallow (around 100 m). [13] Trichodesmium is found primarily in water between 20 and 34 °C and is frequently encountered in tropical and sub-tropical oceans in western boundary currents. [13] Its presence is more pronounced in nitrogen poor water and can easily be seen when blooms form, trapping large Trichodesmium colonies at the surface. [14]

As a diazotroph, Trichodesmium contributes a large portion of the marine ecosystem's new nitrogen, estimated to produce between 60 and 80 Tg of nitrogen per year. [10] Nitrogen fixed by Trichodesmium can either be used directly by the cell, enter the food chain through grazers, be released into dissolved pools, or get exported to the deep sea. [8]

Compared to eukaryotic phytoplankton, Trichodesmium has a slow growth rate, which has been hypothesized to be an adaptation to survival in high energy but low nutrient conditions of oligotrophic waters. Growth rate is limited by iron and phosphate concentrations in the water. In order to obtain these limiting nutrients, Trichodesmium is able to regulate buoyancy using its gas vacuole and move vertically throughout the water column, harvesting nutrients. [13]

Colonies

Various species of Trichodesmium have been described based on morphology and structure of colonies formed. Colonies may consist of aggregates of several to several hundred trichomes and form fusiform (called "Tufts") colonies when aligned in parallel, or spherical (called "Puffs") colonies when aligned radially. [7]

Trichodesmium colonies have been shown to have large degree of associations with other organisms, including bacteria, fungi, diatoms, copepods, tunicates, hydrozoans, and protozoans among other groups. These colonies may provide a source of shelter, buoyancy, and possibly food in the surface waters. Most of these associations appear to be commensal, with the Trichodesmium providing substrate and nutrition while deriving no obvious benefit from the organisms dwelling within the colonies. [15]

Sociality

Trichodesmium are able to transfer between living as a single filament and as a colony. These different morphologies impact the way that the Trichodesmium interact with the environment. Switching between morphologies shows that there are different benefits and costs of existing in each form, and helps scientists understand why transferring from one form to another is necessary. [16] Trichomes, or free-floating single filaments, have higher rates of nitrogen fixation as opposed to colonies. [17] When iron and phosphorus are limiting in the environment, the filamentous Trichodesmium are stimulated to aggregate together to form colonies. [18] Colonies can outcompete trichomes when environmental factors such as predation and rate of respiration for nutrient fixing are at play. [19] The size of the colonies are also linked with the environmental oxygen content, due to the influence of oxygen in the process of photosynthesis. [20]

Trichodesmium colonies are microbially diverse and are considered to be a holobiont, where multiple epibiont bacteria form a singular colony. [21] In these holobionts, Trichodesmium is the core host, but the microbial diversity of the holobiont colony is an essential part of its ecological interactions. [22] Some examples of the Trichodesmium microbiome’s epibiont bacteria include diazotrophs and several cyanobacteria species such as Richelia. [23] Trichodesmium and the epibiont bacteria within the holobiont colonies may perform mutualistic interactions where limiting nutrients such as iron can be mobilized from dust. [24] Other interactions with organisms arise when trichomes start to accumulate together. When colonies of Trichodesmium aggregate in large numbers, it is possible for them to produce a phycotoxin that can affect the growth other microorganisms in the local space of the ocean. [25]

Blooms

Trichodesmium forms large, visible blooms in the surface waters. Blooms have been described in the Baltic Sea, the Red Sea, the Caribbean Sea, the Indian Ocean, the North and South Atlantic and the North Pacific, and off the coast of Australia. [26] One of the earliest blooms was described by E. Dupont in the Red Sea, noticed for turning the surface of the water a reddish color. This bloom was said to extend about 256 nautical miles. Most blooms are several kilometers long and last one to several months. Blooms can form in coastal or oceanic waters, most frequently when the water has been still for some time and surface temperatures exceed 27 °C. [27]

Trichodesmium blooms release carbon, nitrogen and other nutrients into the environment. Some species of Trichodesmium have been shown to release toxins which cause mortalities in some copepods, fish, and oysters. Blooms have also been credited with releasing the toxin which causes clupeotoxism in humans after ingesting fish which have bioaccumulated the toxin during Trichodesmium blooms. The larger impact of these blooms is likely important to the oceanic ecosystem and is the source of many studies. [10] Blooms are traced and tracked using satellite imaging where the highly reflective gas vacuole makes Trichodesmium blooms easily detectable. [28]

It is expected that blooms may increase due to anthropogenic effects in the coming years. Phosphate loading of the environment (through fertilizer pollution, waste disposal, and mariculture) will reduce the growth constraints associated with limited phosphate and likely increase bloom occurrences. [14] Likewise, global warming is projected to increase stratification and cause a shallowing of the mixed layer depth. Both of these factors are associated with Trichodesmium blooms and may also cause an increase in the occurrence of blooms in the future. [10]

Related Research Articles

Nitrogen fixation is a chemical process by which molecular nitrogen (N
2), which has a strong triple covalent bond, is converted into ammonia (NH
3) or related nitrogenous compounds, typically in soil or aquatic systems but also in industry. The nitrogen in air is molecular dinitrogen, a relatively nonreactive molecule that is metabolically useless to all but a few microorganisms. Biological nitrogen fixation or diazotrophy is an important microbe-mediated process that converts dinitrogen (N2) gas to ammonia (NH3) using the nitrogenase protein complex (Nif).

<span class="mw-page-title-main">Cyanobacteria</span> Phylum of photosynthesising prokaryotes that can produce toxic blooms in lakes and other waters

Cyanobacteria, also called Cyanobacteriota or Cyanophyta, are a phylum of autotrophic gram-negative bacteria that can obtain biological energy via photosynthesis. The name 'cyanobacteria' refers to their color, which similarly forms the basis of cyanobacteria's common name, blue-green algae, although they are not scientifically classified as algae. They appear to have originated in a freshwater or terrestrial environment.

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

Heterocysts or heterocytes are specialized nitrogen-fixing cells formed during nitrogen starvation by some filamentous cyanobacteria, such as Nostoc, Cylindrospermum, and Anabaena. They fix nitrogen from dinitrogen (N2) in the air using the enzyme nitrogenase, in order to provide the cells in the filament with nitrogen for biosynthesis.

Diazotrophs are bacteria and archaea that fix atmospheric nitrogen(N2) in the atmosphere into bioavailable forms such as ammonia.

<span class="mw-page-title-main">Algal mat</span> Microbial mat that forms on the surface of water or rocks

Algal mats are one of many types of microbial mat that forms on the surface of water or rocks. They are typically composed of blue-green cyanobacteria and sediments. Formation occurs when alternating layers of blue-green bacteria and sediments are deposited or grow in place, creating dark-laminated layers. Stromatolites are prime examples of algal mats. Algal mats played an important role in the Great Oxidation Event on Earth some 2.3 billion years ago. Algal mats can become a significant ecological problem, if the mats grow so expansive or thick as to disrupt the other underwater marine life by blocking the sunlight or producing toxic chemicals.

<i>Aphanizomenon flos-aquae</i> Species of bacterium

Aphanizomenon flos-aquae is a brackish and freshwater species of cyanobacteria of the genus Aphanizomenon found around the world, including the Baltic Sea and the Great Lakes.

<span class="mw-page-title-main">Cyanophage</span> Virus that infects cyanobacteria

Cyanophages are viruses that infect cyanobacteria, also known as Cyanophyta or blue-green algae. Cyanobacteria are a phylum of bacteria that obtain their energy through the process of photosynthesis. Although cyanobacteria metabolize photoautotrophically like eukaryotic plants, they have prokaryotic cell structure. Cyanophages can be found in both freshwater and marine environments. Marine and freshwater cyanophages have icosahedral heads, which contain double-stranded DNA, attached to a tail by connector proteins. The size of the head and tail vary among species of cyanophages. Cyanophages infect a wide range of cyanobacteria and are key regulators of the cyanobacterial populations in aquatic environments, and may aid in the prevention of cyanobacterial blooms in freshwater and marine ecosystems. These blooms can pose a danger to humans and other animals, particularly in eutrophic freshwater lakes. Infection by these viruses is highly prevalent in cells belonging to Synechococcus spp. in marine environments, where up to 5% of cells belonging to marine cyanobacterial cells have been reported to contain mature phage particles.

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

An akinete is an enveloped, thick-walled, non-motile, dormant cell formed by filamentous, heterocyst-forming cyanobacteria under the order Nostocales and Stigonematales. Akinetes are resistant to cold and desiccation. They also accumulate and store various essential material, both of which allows the akinete to serve as a survival structure for up to many years. However, akinetes are not resistant to heat. Akinetes usually develop in strings with each cell differentiating after another and this occurs next to heterocysts if they are present. Development usually occurs during stationary phase and is triggered by unfavorable conditions such as insufficient light or nutrients, temperature, and saline levels in the environment. Once conditions become more favorable for growth, the akinete can then germinate back into a vegetative cell. Increased light intensity, nutrients availability, oxygen availability, and changes in salinity are important triggers for germination. In comparison to vegetative cells, akinetes are generally larger. This is associated with the accumulation of nucleic acids which is important for both dormancy and germination of the akinete. Despite being a resting cell, it is still capable of some metabolic activities such as photosynthesis, protein synthesis, and carbon fixation, albeit at significantly lower levels.

<i>Aphanizomenon</i> Genus of bacteria

Aphanizomenon is a genus of cyanobacteria that inhabits freshwater lakes and can cause dense blooms. They are unicellular organisms that consolidate into linear (non-branching) chains called trichomes. Parallel trichomes can then further unite into aggregates called rafts. Cyanobacteria such as Aphanizomenon are known for using photosynthesis to create energy and therefore use sunlight as their energy source. Aphanizomenon bacteria also play a big role in the Nitrogen cycle since they can perform nitrogen fixation. Studies on the species Aphanizomenon flos-aquae have shown that it can regulate buoyancy through light-induced changes in turgor pressure. It is also able to move by means of gliding, though the specific mechanism by which this is possible is not yet known.

Cyanobionts are cyanobacteria that live in symbiosis with a wide range of organisms such as terrestrial or aquatic plants; as well as, algal and fungal species. They can reside within extracellular or intracellular structures of the host. In order for a cyanobacterium to successfully form a symbiotic relationship, it must be able to exchange signals with the host, overcome defense mounted by the host, be capable of hormogonia formation, chemotaxis, heterocyst formation, as well as possess adequate resilience to reside in host tissue which may present extreme conditions, such as low oxygen levels, and/or acidic mucilage. The most well-known plant-associated cyanobionts belong to the genus Nostoc. With the ability to differentiate into several cell types that have various functions, members of the genus Nostoc have the morphological plasticity, flexibility and adaptability to adjust to a wide range of environmental conditions, contributing to its high capacity to form symbiotic relationships with other organisms. Several cyanobionts involved with fungi and marine organisms also belong to the genera Richelia, Calothrix, Synechocystis, Aphanocapsa and Anabaena, as well as the species Oscillatoria spongeliae. Although there are many documented symbioses between cyanobacteria and marine organisms, little is known about the nature of many of these symbioses. The possibility of discovering more novel symbiotic relationships is apparent from preliminary microscopic observations.

<span class="mw-page-title-main">Bacterioplankton</span> Bacterial component of the plankton that drifts in the water column

Bacterioplankton refers to the bacterial component of the plankton that drifts in the water column. The name comes from the Ancient Greek word πλανκτος, meaning "wanderer" or "drifter", and bacterium, a Latin term coined in the 19th century by Christian Gottfried Ehrenberg. They are found in both seawater and freshwater.

CandidatusAtelocyanobacterium thalassa, also referred to as UCYN-A, is a diazotrophic species of cyanobacteria commonly found in measurable quantities throughout the world's oceans and some seas. Members of A. thalassa are spheroid in shape and are 1-2 μm in diameter, and provide nitrogen to ocean regions by fixing non biologically available atmospheric nitrogen into biologically available ammonium that other marine microorganisms can use.

Raphidiopsis raciborskii is a freshwater cyanobacterium.

<i>Cyanothece</i> Genus of bacteria

Cyanothece is a genus of unicellular, diazotrophic, oxygenic photosynthesizing cyanobacteria.

<i>Gloeotrichia</i> Genus of bacteria

Gloeotrichia is a large (~2 mm) colonial genus of Cyanobacteria, belonging to the order Nostocales. The name Gloeotrichia is derived from its appearance of filamentous body with mucilage matrix. Found in lakes across the globe, gloeotrichia are notable for the important roles that they play in the nitrogen and phosphorus cycles. Gloeotrichia are also a species of concern for lake managers, as they have been shown to push lakes towards eutrophication and produce deadly toxins.

Trichodesmium erythraeum is a marine cyanobacteria species characterized by its prolific diazotrophic capabilities. They play a dominant role in the ocean ecosystem, supplying a steady and significant source of new, biologically available nitrogen and cycling phosphorus. By nature of its filamentous morphology, T. erythraeum is also known to congregate into large, long colonies, sizeable enough to be seen as sawdust-like particles to the naked eye and pigmented marine regions in satellite images, typically found in oligotrophic tropical and subtropical waters. These blooms are responsible for the famous coloration of the Red Sea.

<i>Crocosphaera watsonii</i> Species of bacterium

Crocosphaera watsonii is an isolate of a species of unicellular diazotrophic marine cyanobacteria which represent less than 0.1% of the marine microbial population. They thrive in offshore, open-ocean oligotrophic regions where the waters are warmer than 24 degrees Celsius. Crocosphaera watsonii cell density can exceed 1,000 cells per milliliter within the euphotic zone; however, their growth may be limited by the concentration of phosphorus. Crocosphaera watsonii are able to contribute to the oceanic carbon and nitrogen budgets in tropical oceans due to their size, abundance, and rapid growth rate. Crocosphaera watsonii are unicellular nitrogen fixers that fix atmospheric nitrogen to ammonia during the night and contribute to new nitrogen in the oceans. They are a major source of nitrogen to open-ocean systems. Nitrogen fixation is important in the oceans as it not only allows phytoplankton to continue growing when nitrogen and ammonium are in very low supply but it also replenishes other forms of nitrogen, thus fertilizing the ocean and allowing more phytoplankton growth.

Trichodesmium thiebautii is a cyanobacteria that is often found in open oceans of tropical and subtropical regions and is known to be a contributor to large oceanic surface blooms. This microbial species is a diazotroph, meaning it fixes nitrogen gas (N2), but it does so without the use of heterocysts. T. thiebautii is able to simultaneously perform oxygenic photosynthesis. T. thiebautii was discovered in 1892 by M.A. Gomont. T. thiebautii are important for nutrient cycling in marine habitats because of their ability to fix N2, a limiting nutrient in ocean ecosystems.

Richelia is a genus of nitrogen-fixing, filamentous, heterocystous and cyanobacteria. It contains the single species Richelia intracellularis. They exist as both free-living organisms as well as symbionts within potentially up to 13 diatoms distributed throughout the global ocean. As a symbiont, Richelia can associate epiphytically and as endosymbionts within the periplasmic space between the cell membrane and cell wall of diatoms.

Margaret Ruth Mulholland is professor at Old Dominion University known for her work on nutrients in marine and estuarine environments.

References

  1. ↑ Bergman, B.; Sandh, G.; Lin, S.; Larsson, H.; Carpenter, E. J. (2012). "Trichodesmium – a widespread marine cyanobacterium with unusual nitrogen fixation properties". FEMS Microbiol. Rev. 37 (3): 1–17. doi:10.1111/j.1574-6976.2012.00352.x. PMC   3655545 . PMID   22928644.
  2. 1 2 Carpenter, E.J.; Capone, D.G.; Rueter, J.G., eds. (1991). Marine Pelagic Cyanobacteria: Trichodesmium and other diazothrophs. Dordrecht.: Kluwer Academic Publishers.
  3. ↑ Capone, Douglas G.; Zehr, Jonathan P.; Paerl, Hans W.; Bergman, Birgitta; Carpenter, Edward J. (1997-05-23). "Trichodesmium, a Globally Significant Marine Cyanobacterium". Science. 276 (5316): 1221–1229. doi:10.1126/science.276.5316.1221. ISSN   0036-8075. S2CID   53710858.
  4. ↑ Ehrenberg,E.O. (1830). "Neue Beobachtungen über blutartige Erscheinungen in Ägypten, Arabien und Sibirien, nebst einer Übersicht und Kritik der früher bekannnten". Ann Phys Chem. 18 (4): 477–514. Bibcode:1830AnP....94..477E. doi:10.1002/andp.18300940402.
  5. 1 2 Gomont, M. (1892). "Monographie des oscillariees (Nostocacees Homocystees) I and II". Ann Sci Nat Bot Ser. 7 (15): 263–368.
  6. 1 2 3 Wille, N. (1904). Hensen,V. (ed.). "Die Schizophyceen der plankton-expedition.Ergebnisse der Plankton-Expedition der Humbol-Stiftung".{{cite journal}}: Cite journal requires |journal= (help)
  7. 1 2 3 4 Siddiqui P.J.A.; Carpenter E.J.; Bergman B. (1991). Carpenter E.J.; Capone D.G.; Rueter J.G. (eds.). "Trichodesmium: Ultrastructure and protein localization". Marine Pelagic Cyanobacteria: Trichodesmium and Other Diazotrophs.
  8. 1 2 Zehr J.P. (2008). Kirchmad (ed.). "Molecular ecological aspects of nitrogen fixation in the marine environment". Microbial Ecology of the Oceans: 481–525. doi:10.1002/9780470281840.ch13. ISBN   9780470281840.
  9. ↑ Bergman, Birgitta; Sandh, Gustaf; Lin, Senjie; Larsson, John; Carpenter, Edward J. (May 2013). "Trichodesmium – a widespread marine cyanobacterium with unusual nitrogen fixation properties". FEMS Microbiology Reviews. 37 (3): 286–302. doi:10.1111/j.1574-6976.2012.00352.x. PMC   3655545 . PMID   22928644.
  10. 1 2 3 4 Bergman, B.; Sandh, G.; Lin, S.; Larsson, H. & Carpenter, E.J. (2012). "Trichodesmium – a widespread marine cyanobacterium with unusual nitrogen fixation properties". FEMS Microbiology Reviews. 37 (3): 1–17. doi:10.1111/j.1574-6976.2012.00352.x. PMC   3655545 . PMID   22928644.
  11. ↑ Gradoville, Mary R.; Crump, Byron C.; Letelier, Ricardo M.; Church, Matthew J.; White, Angelicque E. (2017). "Microbiome of Trichodesmium Colonies from the North Pacific Subtropical Gyre". Frontiers in Microbiology. 8: 1122. doi: 10.3389/fmicb.2017.01122 . PMC   5498550 . PMID   28729854. CC-BY icon.svg Material was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
  12. ↑ Basu, Subhajit; Gledhill, Martha; De Beer, Dirk; Prabhu Matondkar, S. G.; Shaked, Yeala (2019). "Colonies of marine cyanobacteria Trichodesmium interact with associated bacteria to acquire iron from dust". Communications Biology. 2: 284. doi:10.1038/s42003-019-0534-z. PMC   6677733 . PMID   31396564. CC-BY icon.svg Material was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
  13. 1 2 3 Capone D.G.; Zehr J.P.; Paerl H.W.; Bergman B.; Carpenter E.J. (1997). "Trichodesmium, a globally significant marine cyanobacterium". Science. 276 (5316): 1221–1229. doi:10.1126/science.276.5316.1221. S2CID   53710858.
  14. 1 2 Post, A.F. (2005). Huisman J.; Matthijs H.C.P.; Visser P.M. (eds.). "Nutrient limitation of marine cyanobacteria: Molecular ecology of nitrogen limitation in an oligotrophic sea". Harmful Cyanobacteria. Aquatic Ecology Series. 3: 87–108. doi:10.1007/1-4020-3022-3_5. ISBN   978-1-4020-3009-3.
  15. ↑ O'Neil J.M.; Roman M.R. (1991). Carpenter E.J.; Capone D.G.; Rueter J.G. (eds.). "Grazers and associated organisms of Trichodesmium". Marine Pelagic Cyanobacteria: Trichodesmium and Other Diazotrophs: 61–74.
  16. ↑ Eichner, Meri; Inomura, Keisuke; Pierella Karlusich, Juan José; Shaked, Yeala (October 2023). "Better together? Lessons on sociality from Trichodesmium". Trends in Microbiology. 31 (10): 1072–1084. doi: 10.1016/j.tim.2023.05.001 . ISSN   0966-842X. PMID   37244772.
  17. ↑ Eichner, Meri; Thoms, Silke; Rost, Björn; Mohr, Wiebke; Ahmerkamp, Soeren; Ploug, Helle; Kuypers, Marcel M. M.; de Beer, Dirk (April 2019). "N 2 fixation in free-floating filaments of Trichodesmium is higher than in transiently suboxic colony microenvironments". New Phytologist. 222 (2): 852–863. doi:10.1111/nph.15621. ISSN   0028-646X. PMC   6590460 . PMID   30507001.
  18. ↑ Tzubari, Yael; Magnezi, Liel; Be'er, Avraham; Berman-Frank, Ilana (June 2018). "Iron and phosphorus deprivation induce sociality in the marine bloom-forming cyanobacterium Trichodesmium". The ISME Journal. 12 (7): 1682–1693. doi:10.1038/s41396-018-0073-5. ISSN   1751-7370. PMC   6018766 . PMID   29463890.
  19. ↑ Agarwal, Vitul; Inomura, Keisuke; Mouw, Colleen B. (2022-12-21). Veach, Allison (ed.). "Quantitative Analysis of the Trade-Offs of Colony Formation for Trichodesmium". Microbiology Spectrum. 10 (6): e0202522. doi:10.1128/spectrum.02025-22. ISSN   2165-0497. PMC   9769814 . PMID   36374046.
  20. ↑ Eichner, Meri; Basu, Subhajit; Wang, Siyuan; de Beer, Dirk; Shaked, Yeala (June 2020). "Mineral iron dissolution in Trichodesmium colonies: The role of O 2 and pH microenvironments". Limnology and Oceanography. 65 (6): 1149–1160. doi:10.1002/lno.11377. hdl: 21.11116/0000-0005-F9DB-C . ISSN   0024-3590.
  21. ↑ Rouco, Mónica; Haley, Sheean T.; Dyhrman, Sonya T. (December 2016). "Microbial diversity within the T richodesmium holobiont". Environmental Microbiology. 18 (12): 5151–5160. doi:10.1111/1462-2920.13513. ISSN   1462-2912. PMID   27581522.
  22. ↑ academic.oup.com https://academic.oup.com/ismej/article/11/9/2090/7537991 . Retrieved 2024-04-09.{{cite web}}: Missing or empty |title= (help)
  23. ↑ Gradoville, Mary R.; Crump, Byron C.; Letelier, Ricardo M.; Church, Matthew J.; White, Angelicque E. (2017). "Microbiome of Trichodesmium Colonies from the North Pacific Subtropical Gyre". Frontiers in Microbiology. 8: 1122. doi: 10.3389/fmicb.2017.01122 . ISSN   1664-302X. PMC   5498550 . PMID   28729854.
  24. ↑ Basu, Subhajit; Gledhill, Martha; de Beer, Dirk; Prabhu Matondkar, S. G.; Shaked, Yeala (2019-08-02). "Colonies of marine cyanobacteria Trichodesmium interact with associated bacteria to acquire iron from dust". Communications Biology. 2 (1): 284. doi:10.1038/s42003-019-0534-z. ISSN   2399-3642. PMC   6677733 . PMID   31396564.
  25. ↑ Bif, Mariana Bernardi; de Souza, Márcio Silva; Costa, Luiza Dy Fonseca; Yunes, João Sarkis (2019). "Microplankton Community Composition Associated With Toxic Trichodesmium Aggregations in the Southwest Atlantic Ocean". Frontiers in Marine Science. 6. doi: 10.3389/fmars.2019.00023 . ISSN   2296-7745.
  26. ↑ Sellner K.G. (1991). Carpenter E.J.; Capone D.G.; Rueter J.G. (eds.). "Trophodynamics of marine cyanobacteria blooms". Marine Pelagic Cyanobacteria: Trichodesmium and Other Diazotrophs: 75–94.
  27. ↑ Carpenter E.J.; Capone D.G. (1991). Carpenter E.J.; Capone D.G.; Rueter J.G. (eds.). "Nitrogen fixation in Trichodesmium blooms". Marine Pelagic Cyanobacteria: Trichodesmium and Other Diazotrophs: 75–94.
  28. ↑ Zehr J.P.; Paerl H.W. (2008). Kirchman D.L. (ed.). "Molecular ecological aspects of nitrogen fixation in the marine environment". Microbial Ecology of the Oceans (2nd ed.): 481–525. doi:10.1002/9780470281840.ch13. ISBN   9780470281840.

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