Pleurocapsales

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Pleurocapsales
Scientific classification Red Pencil Icon.png
Domain: Bacteria
Phylum: Cyanobacteria
Class: Cyanophyceae
Order: Pleurocapsales
Geitler
Families [1]

The Pleurocapsales are an order of coccooid cyanobacteria. Pleurocapsales are characterized by having boocytes, specialized cells where multiple fission takes place. [2]

Their ecology is mainly endolytic and calcareous, they are found inside rocks and in low light conditions. [3] Pleurocapsales were thought to be related to Chroococcidiopsis but recent work with phylogenetics of the 16S rDNA gene has shown that Chroococcidiopsis belongs to its own order Chroococcidiopsidales. [4]

Some genera within Pleurocapsales form pseudo-ramifications such as Pleurocapsa sp., Odorella sp, and all the genera within the Hyellaceae family. [5]

Historically, the order Pleurocapsales has been one of the least studied orders of cyanobacteria, due to its endolithic ecology making them difficult to observe. [6]

Related Research Articles

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<span class="mw-page-title-main">Endolith</span> Organism living inside a rock

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Cyanotoxins are toxins produced by cyanobacteria. Cyanobacteria are found almost everywhere, but particularly in lakes and in the ocean where, under high concentration of phosphorus conditions, they reproduce exponentially to form blooms. Blooming cyanobacteria can produce cyanotoxins in such concentrations that they poison and even kill animals and humans. Cyanotoxins can also accumulate in other animals such as fish and shellfish, and cause poisonings such as shellfish poisoning.

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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.

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Ornithocercus is a genus of planktonic dinoflagellate that is known for its complex morphology that features considerable lists growing from its thecal plates, giving an attractive appearance. Discovered in 1883, this genus has a small number of species currently categorized but is widespread in tropical and sub-tropical oceans. The genus is marked by exosymbiotic bacteria gardens under its lists, the inter-organismal dynamics of which are a current field of research. As they reside only in warm water, the genus has been used as a proxy for climate change and has potential to be an indicator species for environmental change if found in novel environments.

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References

  1. Komárek J, Kaštovský J, Mareš J, Johansen JR (2014). "Taxonomic classification of cyanoprokaryotes (cyanobacterial genera) 2014, using a polyphasic approach" (PDF). Preslia. 86: 295–335.
  2. Waterbury, J B; Stanier, R Y (1978). "Patterns of growth and development in pleurocapsalean cyanobacteria". Microbiological Reviews. 42 (1): 2–44. doi: 10.1128/mmbr.42.1.2-44.1978 . ISSN   0146-0749. PMC   281417 . PMID   111023.
  3. Stivaletta, N.; Barbieri, R. (January 2009). "Endolithic microorganisms from spring mound evaporite deposits (southern Tunisia)". Journal of Arid Environments. 73 (1): 33–39. doi:10.1016/j.jaridenv.2008.09.024. ISSN   0140-1963.
  4. Fewer, David; Friedl, Thomas; Büdel, Burkhard (April 2002). "Chroococcidiopsis and Heterocyst-Differentiating Cyanobacteria Are Each Other's Closest Living Relatives". Molecular Phylogenetics and Evolution. 23 (1): 82–90. doi:10.1006/mpev.2001.1075. ISSN   1055-7903. PMID   12182405.
  5. Shalygin, Sergei; Huang, I‐Shuo; Allen, Elle H.; Burkholder, JoAnn M.; Zimba, Paul V. (2019-02-13). "Odorella benthonicagen. & sp. nov. (Pleurocapsales, Cyanobacteria): an odor and prolific toxin producer isolated from a California aqueduct". Journal of Phycology. 55 (3): 509–520. doi:10.1111/jpy.12834. ISSN   0022-3646. PMID   30637743. S2CID   58616115.
  6. Shalygin, Sergei; Kavulic, Katherine J.; Pietrasiak, Nicole; Bohunická, Markéta; Vaccarino, Melissa A.; Chesarino, Nicholas M.; Johansen, Jeffrey R. (2019-02-19). "Neotypification of Pleurocapsa fuliginosa and epitypification of P. minor (Pleurocapsales): resolving a polyphyletic cyanobacterial genus". Phytotaxa. 392 (4): 245. doi:10.11646/phytotaxa.392.4.1. ISSN   1179-3163. S2CID   92676499.