Porphyra

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Porphyra
Porphyra umbilicalis, Porphyra purpurea Helgoland.JPG
Porphyra umbilicalis (right) and Porphyra purpurea (front), in Heligoland
Scientific classification OOjs UI icon edit-ltr.svg
(unranked): Archaeplastida
Division: Rhodophyta
Class: Bangiophyceae
Order: Bangiales
Family: Bangiaceae
Genus: Porphyra
C.Agardh 1824
Species [1]

see text

Synonyms [1]

Conchocelis Batters 1892
Phyllona J.Hill 1773

Porphyra is a genus of coldwater seaweeds that grow in cold, shallow seawater. More specifically, it belongs to red algae phylum of laver species (from which comes laverbread), comprising approximately 70 species. [2] It grows in the intertidal zone, typically between the upper intertidal zone and the splash zone in cold waters of temperate oceans. In East Asia, it is used to produce the sea vegetable products nori (in Japan) and gim (in Korea). There are considered to be 60–70 species of Porphyra worldwide [3] and seven around Britain and Ireland, where it has been traditionally used to produce edible sea vegetables on the Irish Sea coast. [4] The species Porphyra purpurea has one of the largest plastid genomes known, with 251 genes. [5]

Life cycle

Porphyra displays a heteromorphic alternation of generations. [6] The thallus we see is the haploid generation; it can reproduce asexually by forming spores which grow to replicate the original thallus. It can also reproduce sexually. Both male and female gametes are formed on the one thallus. The female gametes while still on the thallus are fertilized by the released male gametes, which are non-motile. The fertilized, now diploid, carposporangia after mitosis produce spores (carpospores) which settle, then bore into shells, germinate and form a filamentous stage. This stage was originally thought to be a different species of alga, and was referred to as Conchocelis rosea. That Conchocelis was the diploid stage of Porphyra was discovered in 1949 by the British phycologist Kathleen Mary Drew-Baker for the European species Porphyra umbilicalis . [7] It was later shown for species from other regions as well. [2] [8]

Food

Most human cultures with access to Porphyra use it as a food or somehow in the diet, making it perhaps the most domesticated of the marine algae, [9] known as laver, rong biển (Vietnamese), nori (Japanese:海苔), amanori (Japanese), [10] zakai, gim (Korean:), [10] zǐcài (Chinese:紫菜), [10] karengo, sloke or slukos. [3] The marine red alga Porphyra has been cultivated extensively in many Asian countries as an edible seaweed used to wrap the rice and fish that compose the Japanese food sushi and the Korean food gimbap . In Japan, the annual production of Porphyra species is valued at 100 billion yen (US$1 billion). [11]

P. umbilicalis is harvested from the coasts of Great Britain and Ireland, where it has a variety of culinary uses, including laverbread. [12] In Hawaii, "the species P. atropurpurea is considered a delicacy, called Limu luau". [12] Porphyra was also harvested by the Southern Kwakiutl, Haida, Seechelt, Squawmish, Nuu-chah-nulth, Nuxalk, Tsimshian, and Tlingit peoples of the North American Pacific coast. [12]

Vitamin B12

Porphyra contains vitamin B12 and one study suggests that it is the most suitable non-meat source of this essential vitamin. [13] In the view of the Academy of Nutrition and Dietetics, however, it may not provide an adequate source of B12 for vegans. [14]

Species

Porphyra currently contains 57 confirmed species and 14 unconfirmed species. [15]

Confirmed

Unconfirmed

Following a major reassessment of the genus in 2011, many species previously included in Porphyra have been transferred to Pyropia : for example Pyropia tenera , Pyropia yezoensis , and the species from New Zealand Pyropia rakiura and Pyropia virididentata , leaving only five species out of seventy still within Porphyra itself. [16]

See also

Related Research Articles

<span class="mw-page-title-main">Nori</span> Edible seaweed species of the red algae genus Pyropia

Nori(海苔) is a dried edible seaweed used in Japanese cuisine, usually made from species of the red algae genus Pyropia, including P. yezoensis and P. tenera. It has a strong and distinctive flavor, and is generally made into flat sheets and used to wrap rolls of sushi or onigiri.

<span class="mw-page-title-main">Sea lettuce</span> Genus of seaweeds

The sea lettuces comprise the genus Ulva, a group of edible green algae that is widely distributed along the coasts of the world's oceans. The type species within the genus Ulva is Ulva lactuca, lactuca being Latin for "lettuce". The genus also includes the species previously classified under the genus Enteromorpha, the former members of which are known under the common name green nori.

<span class="mw-page-title-main">Green laver</span> Type of edible green seaweed

Green laver, known as aonori in Japan, sea cabbage (海白菜) or hutai (滸苔) in China, and parae (파래) in Korean, is a type of edible green seaweed, including species from the genera Monostroma and Ulva. It is commercially cultivated in some bay areas in Japan, Korea, and Taiwan, such as Ise Bay. It is rich in minerals such as calcium, magnesium, lithium, vitamins, and amino acids such as methionine. It is also called aosa in some places in Japan.

Pyropia columbina, Southern laver, karengo in the Māori language and luche in the Spanish language, is a species of edible seaweed traditionally harvested by South Island Māori in New Zealand and Chilote people in Chile. It is closely related to Japanese Nori and Welsh laverbread.

<i>Gracilaria</i> Genus of seaweeds

Gracilaria is a genus of red algae (Rhodophyta) notable for its economic importance as an agarophyte, as well as its use as a food for humans and various species of shellfish. Various species in the genus are cultivated among Asia, South America, Africa and Oceania.

<span class="mw-page-title-main">Laverbread</span> Food made from edible seaweed

Laverbread is a food product made from laver, an edible seaweed consumed mainly in Wales as part of local traditional cuisine. The seaweed is commonly found around the west coast of Great Britain, and the coasts of Ireland, where it is known as sleabhac. It is smooth in texture and forms delicate, sheetlike thalli, often clinging to rocks. The principal variety is Porphyra umbilicalis, a red algae which tends to be a brownish colour, but boils down to a dark green pulp when prepared. Laver seaweed has a high content of dietary minerals, particularly iodine and iron. The high iodine content gives the seaweed a distinctive flavour in common with olives and oysters.

<span class="mw-page-title-main">Red algae</span> Division of plant life

Red algae, or Rhodophyta, are one of the oldest groups of eukaryotic algae. The Rhodophyta comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority of species (6,793) are found in the Florideophyceae (class), and mostly consist of multicellular, marine algae, including many notable seaweeds. Red algae are abundant in marine habitats but relatively rare in freshwaters. Approximately 5% of red algae species occur in freshwater environments, with greater concentrations found in warmer areas. Except for two coastal cave dwelling species in the asexual class Cyanidiophyceae, there are no terrestrial species, which may be due to an evolutionary bottleneck in which the last common ancestor lost about 25% of its core genes and much of its evolutionary plasticity.

<span class="mw-page-title-main">Edible seaweed</span> Algae that can be eaten and used for culinary purposes

Edible seaweed, or sea vegetables, are seaweeds that can be eaten and used for culinary purposes. They typically contain high amounts of fiber. They may belong to one of several groups of multicellular algae: the red algae, green algae, and brown algae. Seaweeds are also harvested or cultivated for the extraction of polysaccharides such as alginate, agar and carrageenan, gelatinous substances collectively known as hydrocolloids or phycocolloids. Hydrocolloids have attained commercial significance, especially in food production as food additives. The food industry exploits the gelling, water-retention, emulsifying and other physical properties of these hydrocolloids.

Bangia is an extant genus of division Rhodophyta that grows in marine or freshwater habitats. Bangia has small thalli with rapid growth and high reproductive output, and exhibits behavior characteristic of r-selected species. The plants are attached by down-growing rhizoids, usually in dense purple-black to rust-colored clumps. The chloroplasts of Bangia, like others in the division Rhodophyta, contain chlorophyll a and sometimes chlorophyll d, as well as accessory pigments such as phycobilin pigments and xanthophylls. Depending on the relative proportions of these pigments and the light conditions, the overall color of the plant can range from green to red to purple to grey; however, the red pigment, phycoerythrin, is usually dominant.

<span class="mw-page-title-main">Gamet</span> Dried edible seaweed from the Philippines

Gamet is a traditional dried edible seaweed from Ilocos Norte and Cagayan of the Philippines, particularly from the town of Burgos. Gamet are dried into sheets or thin cakes called pedazo, which are characteristically purplish-black in color. It is used widely in soups, salads, omelets and other dishes, in the cuisines of the northern Philippines.

<span class="mw-page-title-main">Bangiales</span> Order of red algae

Bangiales is an order of multicellular red algae of the class Bangiophyceae containing the families Bangiaceae, Granufilaceae, and possibly the extinct genus Rafatazmia with one species, Rafatazmia chitrakootensis. They are one of the oldest eukaryotic organisms, possibly dating back to 1.6 billion years old. Many species are used today as food in different cultures worldwide. Their sizes range from microscopic (Bangiomorpha) to up to two meters long. Many of its species are affected by Pythium porphyrae, a parasitic oomycete. Similar to many other species of red algae, they reproduce both asexually and sexually. They can be both filamentous or foliose, and are found worldwide.

<i>Laurencia</i> Genus of algae

Laurencia is a genus of red algae that grow in temperate and tropical shore areas, in littoral to sublittoral habitats, at depths up to 65 m (213 ft).

<i>Pyropia tenera</i> Species of seaweed

Pyropia tenera, also known as gim or nori, is a red algal species in the genus Pyropia. The specific name, tenera, means "delicate" and alludes to its small size. It typically grows to lengths between 20 and 50 cm. It is most typically found in the western Pacific Ocean and the Indian Ocean.

<i>Hypnea</i> Genus of algae

Hypnea is a genus of red algae, and a well known carrageenophyte.

<i>Pyropia</i> Genus of algae

Pyropia is a genus of red algae in the family Bangiaceae. It is found around the world in intertidal zones and shallow water. The genus has folding frond-like blades which are either red, brown or green. Some Pyropia species are used to create nori, and are thus important subjects for aquaculture.

Pythium porphyrae, is a parasitic species of oomycete in the family Pythiaceae. It is the cause of red rot disease or red wasting disease, also called akagusare (赤ぐされ) in Japanese. The specific epithet porphyrae (πορφυρα) stems from the genus of one of its common hosts, Porphyra, and the purple-red color of the lesions on the thallus of the host. However, many of its hosts have been moved from the genus Porphyra to Pyropia.

<span class="mw-page-title-main">Bangiaceae</span> Family of algae

Bangiaceae is a family of red algae in the order Bangiales. It contains laver, used to make laverbread, and various species in the genus of Pyropia are used to make nori.

<i>Dictyota</i> Genus of seaweed in the family Dictyotaceae

Dictyota is a genus of brown seaweed in the family Dictyotaceae. Species are predominantly found in tropical and subtropical seas, and are known to contain numerous chemicals (diterpenes) which have potential medicinal value. As at the end of 2017, some 237 different diterpenes had been identified from across the genus.

<i>Spatoglossum</i> Genus of algae

Spatoglossum is a marine brown algal genus in the family Dictyotaceae, with a worldwide distribution

References

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  2. 1 2 Brodie, J.A. and Irvine, L.M. 2003. Seaweeds of the British Isles. Volume 1 Part 3b. The Natural History Museum, London. ISBN   1 898298 87 4
  3. 1 2 Kain, J.M. 1991. Cultivation of attached seaweeds. in Guiry, M.D. and Blunden, G. 1992. Seaweed Resources in Europe: Uses and Potential. John Wiley and Sons, Chichester ISBN   0-471-92947-6
  4. Hardy, F.G. and Guiry, M.D. 2006. A Check-list and Atlas of the Seaweeds of Britain and Ireland. British Phycological Society, London. ISBN   3-906166-35-X
  5. The Chlamydomonas Sourcebook: Organellar and Metabolic Processes Volum 2
  6. Porphyra life cycle Archived 2007-04-11 at the Wayback Machine [ dead link ]
  7. Drew, Kathleen M. (1949). "Conchocelis-phase in the life-history of Porphyra umbilicalis (L.) Kütz". Nature. 164 (4174): 748–749. Bibcode:1949Natur.164..748D. doi:10.1038/164748a0. S2CID   4134419.
  8. Thomas, D. 2002. Seaweeds. The Natural History Museum, London. ISBN   0-565-09175-1
  9. Mumford, T.F. and Miura, A. 4.Porphyra as food: cultivation and economics. in Lembi, C.A. and Waaland, J.R. 1988. Algae and Human Affairs. Cambridge University Press, Cambridge. ISBN   0-521-32115-8
  10. 1 2 3 Abbott, Isabella A (1989). Lembi, Carole A.; Waaland, J. Robert (eds.). Algae and human affairs (Food and food products from seaweeds). Cambridge University Press, Phycological Society of America. p. 141. ISBN   978-0-521-32115-0.
  11. Aoki, Y. and Kamei, Y. 2006 Preparation of recombinant polysaccharide-degrading enzymes from the marine bacterium, Pseudomonas sp. ND137 for the production of protoplasts of Porphyra yezoensisEur. J. Phycol.41: 321-328.
  12. 1 2 3 "Laver Seaweed – A Foraging Guide to Its Food, Medicine and Other Uses". eatweeds.co.uk. 30 August 2018. Retrieved 22 March 2021.
  13. Watanabe F, Yabuta Y, Bito T, Teng F (May 2014). "Vitamin B₁₂-containing plant food sources for vegetarians". Nutrients. 6 (5): 1861–73. doi: 10.3390/nu6051861 . PMC   4042564 . PMID   24803097. A nutritional analysis of six vegan children who had consumed vegan diets including brown rice and dried purple laver (nori) for 4–10 years suggested that the consumption of nori may prevent Vitamin B12 deficiency in vegans.
  14. Melina V, Craig W, Levin S (2016). "Position of the Academy of Nutrition and Dietetics: Vegetarian Diets". J Acad Nutr Diet. 116 (12): 1970–1980. doi:10.1016/j.jand.2016.09.025. PMID   27886704. S2CID   4984228. Fermented foods (such as tempeh), nori, spirulina, chlorella algae, and unfortified nutritional yeast cannot be relied upon as adequate or practical sources of B-12.39,40 Vegans must regularly consume reliable sources— meaning B-12 fortified foods or B-12 containing supplements—or they could become deficient, as shown in case studies of vegan infants, children, and adults.
  15. Michael D. Guiry (2024). "Porphyra C.Agardh, 1824". WoRMS. World Register of Marine Species . Retrieved 17 April 2024.
  16. Sutherland; et al. (October 2011). "A New Look at an Ancient Order: Generic Revision of the Bangiales (Rhodophyta)". J. Phycol. 47 (5): 1131–1151. doi:10.1111/j.1529-8817.2011.01052.x. PMID   27020195. S2CID   2779596.