Arthrospira: Difference between revisions

The common name, [[Spirulina (dietary supplement)|spirulina]], refers to the dried biomass of ''[[Arthrospira platensis]]'',<ref>{{cite book |last1=Gershwin |first1=ME |last2=Belay |first2=A |date=2007|title=Spirulina in human nutrition and health | publisher= CRC Press, USA}}</ref> whicha belongstype to the oxygenic photosynthetic bacteria that cover the groupsof [[Cyanobacteria]], andwhich Prochloralesare oxygenic photosynthetic bacteria. These photosynthetic organisms were first considered to be algae, a very large and diverse group of [[Eukaryote|eukaryotic]] organisms, until 1962 when they were reclassified as [[Prokaryote|prokaryotes]] and named Cyanobacteria.<ref>{{cite journal |last1=Stanier |first1=RY |last2=Van Niel |first2=Y |title=The concept of a bacterium |journal=ArchArchiv Mikrobiolfür Mikrobiologie |volume=42 |pages=17–35 |date=January 1962 |doi=10.1007/bf00425185 |pmid=13916221|s2cid=29859498 }}</ref> This designation was accepted and published in 1974 by ''[[Bergey's Manual of Determinative Bacteriology]]''.<ref name="ReferenceA">{{cite journal |last1=Sánchez |first1=Bernal-Castillo |last2=Van Niel |first2=J |last3=Rozo |first3=C | last4=Rodríguez |first4=I |title=''Spirulina (arthrospiraArthrospira)'': an edible microorganism: a review |journal=Universitas Scientiarum |volume=8 | issue=1 |pages=7–24 |date=2003 |url=https://www.researchgate.net/publication/292588254 }}</ref> Scientifically, quite a distinction exists between the ''Spirulina'' and ''Arthrospira'' genera. Stizenberger, in 1852, gave the name ''Arthrospira'' based on the presence of septa, its helical form, and its multicellular structure, and [[Maurice Gomont|Gomont]], in 1892, confirmed the aseptate form of the genus '' Spirulina''. Geitler in 1932 reunified both members designating them as ''Spirulina'' without considering the septum.<ref name=":0">{{Citecite journal |urllast1=Siva Kiran |first1=RR http://www.iapen.co.in/jnutres/34-98-6-PB.pdf|titlelast2=Madhu |first2=GM |last3=Satyanarayana |first3=SV |title=''Spirulina'' in combating Protein Energy Malnutrition (PEM) and Protein Energy Wasting (PEW) - A review|last |journal=Journal Sivaof Kiran|firstNutrition =Research RR|author2date=Madhu2016 GM|author3volume=Satyanarayana3 SV|date issue=1 2016|journal pages=62–79 Journal of Nutrition Research|accessdoi=10.55289/jnutres/v3i1.5|doi-date access= February 20, 2016free}}</ref> Research on [[microalgae]] was carried out in the name of ''Spirulina'', but the original species used to produce the dietary supplement spirulina belongs to the genus ''Arthrospira''. This misnomer has been difficult to correct.<ref name="ReferenceA"/>

At present, taxonomy states that the name spirulina for strains which are used as [[food supplement]]s is inappropriate, and agreement exists that ''Arthrospira'' is a distinct genus, consisting of over 30 different species, including ''A. platensis'' and ''A. maxima''.<ref>

| journal=DNA Res.Research

The genus ''Arthrospira'' comprises helical [[Trichome|trichomes]] of varying size and with various degrees of coiling, including tightly-coiled morphology to a straight form.<ref name="ciferri"/>

''Arthrospira'' is very rich in [[protein]]s,<ref name="ciferri" /><ref name="ReferenceBFAO Spirulina Review" /> and constitute 53 to 68 percent by dry weight of the contents of the cell.<ref>{{cite journal|last1=Phang|first1=S. M.|title=Spirulina cultivation in digested sago starch factory wastewater|journal=Journal of Applied Phycology|date=2000|volume=12|issue=3/5|pages=395–400|doi=10.1023/A:1008157731731|s2cid=20718419}}</ref>

Its protein harbours all [[Essential amino acid|essential amino acids]].<ref name="ReferenceBFAO Spirulina Review" /> ''Arthrospira'' also contain high amounts of [[polyunsaturated fatty acid]]s (PUFAs), about 1.5–2 percent, and a total lipid content of 5–6 percent.<ref name="ReferenceBFAO Spirulina Review" /> These PUFAs contain the [[γ-linolenic acid]] (GLA), an [[omega-6 fatty acid]].<ref>{{cite journal|last1=Spolaore|first1=Pauline|s2cid=16896655|display-authors=etal|title=Commercial applications of microalgae|journal=Journal of Bioscience and Bioengineering|date=2006|volume=101|issue=2|pages=87–96|doi=10.1263/jbb.101.87|pmid=16569602}}</ref> Further contents of ''Arthrospira'' include vitamins, minerals and [[Photosynthetic pigment|photosynthetic pigments]].<ref name="ReferenceBFAO Spirulina Review" />

Species of the genus ''Arthrospira'' have been isolated from alkaline [[Brackish water|brackish]] and [[Saline water|saline waters]] in tropical and subtropical regions. Among the various species included in the genus,'' A. platensis'' is the most widely distributed and is mainly found in Africa, but also in Asia. ''A. maxima'' is believed to be found in California and Mexico.<ref name=":0"/> ''A. platensis'' and ''A. maxima'' occur naturally in tropical and subtropical lakes with alkaline [[pH]] and high concentrations of [[carbonate]] and [[bicarbonate]].<ref name="FAO Spirulina Review">{{cite web|title=A Review on Culture, Production and Use of Spirulina as Food dor Humans and Feeds for Domestic Animals and Fish|url=ftp://ftp.fao.org/docrep/fao/011/i0424e/i0424e00.pdf|publisher=Food and Agriculture Organization of The United Nations|access-date=November 20, 2011|author=Habib, M. Ahsan B.|author2=Parvin, Mashuda|author3= Huntington, Tim C.|author4= Hasan, Mohammad R.|year=2008}}</ref> ''A. platensis'' occurs in Africa, Asia and South America, whereas ''A. maxima'' is confined to Central America. ''A. pacifica'' is endemic to the Hawaiian islands.<ref name="vonshak">{{cite book|last1=Vonshak, A. (ed.). |first1=Avigad|title=''Spirulina platensis (Arthrospira)'': Physiology, Cell-biologyBiology andAnd Biotechnology.'' London: Taylor & Francis,|date=2002|publisher=CRC 1997.Press|isbn=9780203483961|language=en}}</ref> Most cultivated spirulina is produced in open-channel [[Raceway pond|raceway ponds]], with paddle-wheels used to agitate the water.<ref name="FAO Spirulina Review" /> The largest commercial producers of spirulina are located in the United States, Thailand, India, Taiwan, China, Pakistan, Myanmar, Greece and Chile.<ref name="vonshak"/>

Spirulina is widely known as a [[food supplement]], but there are other possible uses for this cyanobacterium. As an example, it is suggested to be used medically for patients for whom it is difficult to chew or swallow food, or as a natural and cheap drug delivery system.<ref>{{cite journal|last1=Adiba|first1=B. D.|display-authors=etal|title=Preliminary characterization of food tablets from date ( ''Phoenix dactylifera'' L.) and spirulina ( ''Spirulina'' sp.) powders|journal=Powder Technology|date=2008|volume=208|issue=3|pages=725–730|doi=10.1016/j.powtec.2011.01.016}}</ref> Further, promising results in the treatment of certain cancers, allergies and anemia, as well as hepatotoxicity and vascular diseases were found.<ref>{{cite journal|last1=Asghari|first1=A.|display-authors=etal|title=A Review on Antioxidant P ropertiesProperties of Spirulin|journal=Journal of Applied Biotechnology Reports|date=2016}}</ref> Spirulina may also be used as a healthy addition to animal feed<ref>{{cite journal|last1=Holman|first1=B. W. B.|display-authors=etal|title=Spirulina as a livestock supplement and animal feed|journal=Journal of Animal Physiology and Animal Nutrition|date=2012|volume=97|issue=4|pages=615–623|doi=10.1111/j.1439-0396.2012.01328.x|pmid=22860698|doi-access=free}}</ref> if the price of its production can be further reduced. Spirulina can be used in technical applications, such as the biosynthesis of [[silver nanoparticle]]s, which allows the formation of metallic silver in an environmentally friendly way.<ref>{{cite journal|last1=Mahdieh|title=Green biosynthesis of silver nanoparticles by ''Spirulina platensis'' |journal=Scientia Iranica|date=2012|volume=19|issue=3|pages=926–929|doi=10.1016/j.scient.2012.01.010|doi-access=free}}</ref>

In the creation of textiles it harbors some advantages, since it can be used for the production of antimicrobial textiles<ref name="ReferenceC">{{cite journal|last1=Mahltig|first1=B|display-authors=etal|title=Modification of algae with zinc, copper and silver ions for usage as natural composite for antibacterial applications|journal=Materials Science and Engineering|date=2013|volume=33|issue=2|pages=979–983|doi=10.1016/j.msec.2012.11.033|pmid=25427514|doi-access=}}</ref> and paper or polymer materials.<ref name="ReferenceC"/> They also may have an antioxidant effect<ref>{{cite journal |last1=Kumaresan V,|first1=Venkatesh |last2=Sannasimuthu A,|first2=Anbazahan |last3=Arasu M,|first3=Mariadhas Valan |last4=Al-Dhabi NA,|first4=Naif Abdullah |last5=Arockiaraj J.|first5=Jesu |title=Molecular insight into the metabolic activities of a protein-rich micro alga, ''Arthrospira platensis'' by de novo transcriptome analysis. Mol|journal=Molecular BiolBiology RepReports (|date=2018). https://rdcu|volume=45 |issue=5 |pages=829–838 |doi=10.be1007/20jCs11033-018-4229-1|pmid=29978380 |s2cid=254835532 }}</ref> and may maintain the [[ecological balance]] in aquatic bodies and reduces various stresses in the aquatic environment.<ref>{{cite journal |last1=Kumaresan V,|first1=Venkatesh |last2=Nizam F,|first2=Faizal |last3=Ravichandran G,|first3=Gayathri |last4=Viswanathan K,|first4=Kasi |last5=Palanisamy R,|first5=Rajesh et|last6=Bhatt al.|first6=Prasanth |last7=Arasu |first7=Mariadhas Valan |last8=Al-Dhabi |first8=Naif Abdullah |last9=Mala |first9=Kanchana |last10=Arockiaraj |first10=Jesu |title=Transcriptome changes of blue-green algae, ''Arthrospira'' sp. in response to sulfate stress. |journal=Algal Research (|date=2017) |volume=23, 96-103.|pages=96–103 https://|doi.org/=10.1016/j.algal.2017.01.012}}</ref>

The optimal growth temperature for ''A. platensis'' is 35–38&nbsp;°C. This poses a major limiting factor outside the tropics, confining growth to the summer months.<ref>{{cite book|last1=Vonshak|first1=A|title=Spirulina platensis (Arthrospira). In Physiology, Cell Biology and Biotechnology|date=1997|publisher=Taylor and Francis|location=Basingstoke, Hants, London}}</ref> ''A. platensis'' has been grown in fresh water, as well as in brackish water and sea water.<ref>{{cite journal|last1=Materassi|first1=R|display-authors=etal|title=''Spirulina'' culture in sea-water|journal=Appl.Applied Microbiol.Microbiology and Biotechnology Biotechnol.|date=1984|volume=19|issue=6|pages=384–386|doi=10.1007/bf00454374|s2cid=31267876}}</ref> Apart from mineral fertilizer, various sources such as waste effluents, and effluents from fertilizer, starch and noodle factories have been used as a nutrient source.<ref name="vonshak"/>

Another problem includes water loss due to evaporation. Both of these problems can be addressed by covering the channels with transparent [[polyethylene]] film.<ref>{{cite web|last1name=Sánchez|first1=M.|display-authors=etal|title=Spirulina (Arthrospira): An edible microorganism. A Review.|url=http://yalor.yru.ac.th/~dolah/notes/SPIRULINA.pdf}}{{Dead link|date=October 2019 |bot=InternetArchiveBot |fix-attempted=yes }}<"ReferenceA"/ref>

Closed systems have the advantage of being able to control the physical, chemical and biological environment. This allows for increased yield, and more control of the nutrient level. Typical forms such as tubes or polyethylene bags, also offer a larger surface-to-volume ratios than open pond systems,<ref>{{cite journal|last1=Tredici|first1=M|last2=Materassi|first2=R|title=From open ponds to vertical alveolar panels: the Italian experience in the development of reactors for the mass cultivation of phototrophic microorganisms|journal=Journal of Applied Phycology|date=1992|volume=4|issue=3|pages=221–231|doi=10.1007/bf02161208|s2cid=20554506}}</ref> thus increasing the amount of sunlight available for photosynthesis. These closed systems help expanding the growing period into the winter months, but often lead to overheating in summer.<ref>{{cite journal|last1=Tomaselli|first1=L|display-authors=etal|title=Recent research on ''Spirulina'' in Italy|journal=Hydrobiology|date=1987|volume=151/152|pages=79–82|doi=10.1007/bf00046110|s2cid=9903582}}</ref>

Cultivation of ''Arthrospira'' has occurred for a long period of time,{{Vague|reason=date?|date=December 2020}} especially in Mexico and around Lake Chad on the African continent. During the 20th21st century however, its beneficial properties were rediscovered and therefore studies about ''Arthrospira'' and its production increased.<ref name="ahsan">{{citeFAO book|last1=Ahsan|first1=M|display-authors=etal|title=ASpirulina Review" on Culture, Production and use of Spirulina as Food for Humans and Feeds for Domestic Animals and Fish|date=2008|publisher=FAO Fisheries and Aquaculture Circular No. 1034|location=Rome}}</ref> In the past decades, large-scale production of the cyanobacterium developed.<ref name=":1">{{cite book|last1=Whitton|first1=B. A.|title=Ecology of Cyanobacteria II: Their Diversity in Space and Time|date=2012|publisher=Springer|pages=701–711}}</ref> Japan started in 1960, and in the following years Mexico and several other countries over all continents, such as China, India, Thailand, Myanmar and the United States started to produce on large-scale.<ref name="ahsanFAO Spirulina Review" /> In little time, China has become the largest producer worldwide.<ref name=":1" /> A particular advantage of the production and use of spirulina is that its production can be conducted at a number of different scales, from household culture to intensive commercial production over large areas.

The international market of spirulina is divided into two target groups: the one includes NGO’s and institutions focusing on malnutrition and the other includes health conscious people. There are still some countries, especially in Africa, that produce at a local level. Those could respond to the international demand by increasing production and [[economies of scale]]. Growing the product in Africa could offer an advantage in price, due to low costs of labour. On the other hand, African countries would have to surpass quality standards from importing countries, which could again result in higher costs.<ref name="smart fish" />

* {{AlgaeBase genus|name=Arthrospira|id=r81faff710221cf5a43076}}