Laminaria

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Laminaria
Laminaria hyperborea - Köhler–s Medizinal-Pflanzen-214.jpg
Laminaria hyperborea
Scientific classification
(unranked): SAR
Superphylum: Heterokonta
Class: Phaeophyceae
Order: Laminariales
Family: Laminariaceae
Genus: Laminaria
J. V. Lamouroux
Species

c. 30 species; see text

Laminaria is a genus of 31 species of brown algae commonly called "kelp". Some species are also referred to as tangle. This economically important genus is characterized by long, leathery laminae and relatively large size. Some species are referred to by the common name Devil's apron, due to their shape,[1] or sea colander, due to the perforations present on the lamina.[2] It is found in the north Atlantic Ocean and the northern Pacific Ocean at depths from 8 to 30 m (26 to 98 ft) (exceptionally to 120 m (390 ft) in the warmer waters of the Mediterranean Sea and off Brazil).[3] Laminaria form a habitat for many fish and invertebrates. [4]

The life cycle of Laminaria has heteromorphic alternating of generations which differs from Fucus. At meiosis the male and female zoospores are produced separate then germinate into male and female gametophytes. The female egg matures in the oogonium until the male sperm fertilizes it.[5] Life-Cycle: The most apparent form of Laminaria is its sporophyte phase, a structure composed of the holdfast, the stipe, and the blades. While it spends its time predominately in the sporophyte phase, it alternates between the sporophyte and its microscopic gametophyte phase.[3]

Laminaria japonica (J. E. Areschoug – Japón) [6] is now regarded as a synonym of Saccharina japonica[7] and Laminaria saccharina is now classified as Saccharina latissima.[8]

History[edit]

Laminaria arrived in China from Hokkaido, Japan in the late 1920s. Once in China, Laminaria was cultivated on a much larger industrial scale.[9] The rocky shores at Dalian, the northern coast of the Yellow Sea, along with the cold waters provided excellent growing conditions for these species. Laminaria was harvested for food and 1949 yielded 40.3 metric tons of dry weight.[9] Laminaria need cold water to survive and can only live 36° N latitude. With summer the heat difference in the summer, some of the southern plants quickly die due to increased temperatures.

In 1949, the Chinese started to commercially grow laminaria as a crop. This increased the production of dry weight to 6,200 metric tons. Farming laminaria is still a large production for China. However, after the 1980s production drop due to new technology in mariculture.[9]

Farming practices[edit]

Laminaria is generally farmed using the floating raft method in which young laminaria sporophytes are attached to submerged ropes. These ropes are then attached to floating rafts.[9]

Ecology[edit]

Laminaria is found in colder ocean waters, such as arctic regions.[10] Preferring to say in regions where there are rocky shores, this allows the laminaria to attach. Due to the height of the laminaria, they provide protection for creatures that the open ocean does not often give. Invertebrates are just one of the organisms that live among the algae. Sea snails and other invertebrates feed on the blades (leaves) of the laminaria. Other organisms like sea urchins feed on the holdfasts which end up killing the algae.[11] Red Sea Urchins, found on the North America Pacific Coast, can decimate kelp, like Laminaria, if the urchins are not managed by Sea Otters

The sexual life cycle of Laminaria

Life cycle[edit]

Laminaria expresses a haplo-diplophasic life history in which it alternates from a macroscopic thallic sporophyte structure, consisting of the holdfast, a stipe, and the blades, to a filamentous, microscopic gametophyte. The sporophyte structure of laminaria can grow to 7 metres (23 ft), which is large in comparison to other algae, but still smaller than the giant kelps such as Macrocystis and Nereocystic that can grow up to 40–50 metres (130–160 ft). The gametophyte structure, however is no more than a few millimeters in length. In opposition to the gametophyte phase, which only consists of one type of tissue, the more complex sporophyte phase is made up of different types of tissue. One of these tissues includes a sieve-like element which translocates photassimilates(Schmitz 1982). These structures are very similar to mesophyll cells found in higher plant leaves.[12]

Uses[edit]

Medical[edit]

A laminaria stick may be used to slowly dilate the cervix to induce labor and delivery, or for surgical procedures including abortions or to facilitate the placement of an Intrauterine Device. The stick is made up of a bundle of dried and compressed laminaria that expands as water is absorbed.

Laminaria is a main source of the rare element, iodine, which is commonly used to promote thyroid health.[12]

Certain carbohydrates such as mannitol, laminarin, and alginate can be extracted from laminaria. Mannitol is used to decrease high pressure in the eyes, and to lower excessive intracranial pressure. Laminarin has two forms, soluble and unsoluble. The soluble form of Laminarin has high antitumor activity, can be used in the treatment of antibiotic-resistant nosocomal infections, can aid in normalizing enteric metabolisms, helps to improve engymatic processes of the intestine and does not possess antigenic or pyrogenic properties. Laminarin continues to be of active study in today’s medical field.[13]

Laminaria has also been used for heartburn and indigestion relief under the brandname phycodol[14]

Food[edit]

Various species of Laminaria have been used for food purposes since ancient times wherever humans have encountered them. Typically, the prepared parts, usually the blade, are consumed either immediately after boiling in broth or water, or consumed after drying, or drying then re-hydrating. The greater proportion of commercial cultivation is for algin, iodine, and mannitol, which are used in a range of industrial applications. In South Korea it is processed into a sweetmeat known as Laminaria jelly, in other countries it is also used in fresh salad form, which is also canned for preservation for deliverу and selling purposes in other regions. Many countries produce and consume laminaria products, but the largest is China.[15]

Energy[edit]

Due to their ability to grow underwater and in salt water, algae is being looked into as a source of biofuel. Laminaria is one of the five macroalgaes farmed for products such as food. Those five genera contribute to 76% of the total tonnage for farmed macroalgae. Laminaria is less desired due to the high ash content when burned. Laminaria has an ash content of 33% while wood has about a 2% ash content when burned. The large amount of ash can be problematic for efficiency of the boilers. Algae have a large water content which requires a large about of energy to dry the algae out before being able to properly use it.[16]

More research is being done with anaerobic digestion, which is the most promising practice to extract energy from Laminaria. There are still issues with moving forward with anaerobic digestion, such as cost. [17]

Metal absorption[edit]

The ability of laminaria along with other brown algae to absorb heavy metals is a current area of interest in terms of potentially using them to remove heavy metals from wastewater.[18] Laminaria has been shown by recent research to have a favorable M/G ratio for heavy metal absorption in its alginate. This M/G ratio is the ratio between the L-gluronate (G) and D-mannuronate (M) in the alginate, a natural anionic polymer that is found in all brown algae. This alginate is able to form a gel that contains carboxyl groups that can bind heavy metal cations such as Cu2+
, Cd2+
, and Pb2+
, thereby allowing these metals to be removed from wastewater.[19]

Species[edit]

Laminaria digitata, Cyanotype by Anna Atkins, 1843

References[edit]

  1. ^ "Devil's Apron". Webster's Revised Unabridged Dictionary. C. & G. Merriam Co. 1913. 
  2. ^ "Devil's apron - Sea Vegetable". Archived from the original on October 16, 2008. Retrieved 2009-02-06. [unreliable source?]
  3. ^ a b Guiry, Michael. "Kelps: Laminaria and Saccharina". Archived from the original on November 19, 2007. Retrieved 2009-02-06. [unreliable source?]
  4. ^ "Laminaria | algae". Encyclopædia Britannica. Retrieved 2017-03-30. 
  5. ^ Evert, Ray; Eichhorn, Susan (2013). Raven Biology of Plants. USA: W. H. Freeman and Company. p. 338. ISBN 978-1-4292-1961-7. 
  6. ^ T. Tori (1998). An Illustrated Atlas of the Life History of Algae. Uchida Rokakuho Publishing Co., Ltd. Tokyo. ISBN 4-7536-4057-4. [page needed]
  7. ^ M. D. Guiry & Wendy Guiry (2006-09-29). "Laminaria japonica J. E. Areschoug". AlgaeBase. 
  8. ^ Saccharina latissima (Linnaeus) J.V. Lamouroux The Seaweed Site. Retrieved 2011-09-20.
  9. ^ a b c d Culture of Kelp (Laminaria japonica) in China. FAO. June 1989.
  10. ^ Singh, V; Pande, P.C.; Jain, D.K. (2009). Textbooks of Botany. Meerut, IN: Rastogi Publications. 
  11. ^ Administration, US Department of Commerce, National Oceanic and Atmospheric. "What lives in a kelp forest". oceanservice.noaa.gov. Retrieved 2017-04-06. 
  12. ^ a b Crepineau, Florent; Roscoe, Thomas; Kaas, Raymond; Kloareg, Bernard; Boyen, Catherine (April 2000). "Characterisation of complementary DNAs from the expressed sequence tag analysis of life cycle stages of Laminaria digitata (Phaeophyceae)". Plant Molecular Biology. 43 (4): 503–513. doi:10.1023/A:1006489920808. 
  13. ^ Strusovskaya, O.G.; Byjuklinskaya, O.V. (2009). "Possibilities of laminarin use in medicine. Literature review.". Human Ecology. 11: 33–36. 
  14. ^ http://www.phycodol.com/
  15. ^ Culture of Kelp (Laminaria japonica) in China. FAO. June 1989. 
  16. ^ Milledge, John J.; Smith, Benjamin; Dyer, Philip W.; Harvey, Patricia (2014). "Macroalgae-Derived Biofuel: A Review of Methods of Energy Extraction from Seaweed Biomass" (PDF). Energies. 7. 
  17. ^ Bruton, Tom; Dr. Lyons, Henry; Dr. Lerat, Yannick; Dr. Stanley, Michele; Rasmussen, Michael Bo (February 2009). "A Review of the Potential of Marine Algae as a Source of Biofuel in Ireland" (PDF). Sustainable Energy. 
  18. ^ Nestle, Nikolaus F.E.I.; Kimich, Rainer (March 1996). "NMR Imaging of Heavy Metal Absorption in Alginate, Immobilized Cells, and Kombu Algal Biosorbents". Biotechnology and Bioengineering. 51: 538–543. 
  19. ^ Papageorgiou, Sergios K.; Katsaros, Fotios; Nolan, J. W.; Kanellopoulos, Nick K. (November 2006). "Heavy Metal Sorption by Calcium Alginate Beads From Laminaria digitata". Journal of Hazardous Materials. B137: 1765–1772. 
  20. ^ Yoneshigue-Valentin, Yocie (1990). "The life cycle of Laminaria abyssalis (Laminariales, Phaeophyta) en cultivo". Hydrobiologia. 204–205 (1): 461–466. doi:10.1007/BF00040271. 
  21. ^ M. D. Guiry (2006-03-26). "Laminaria abyssalis A. B. Joly & E. B. Oliveira". AlgaeBase. 
  22. ^ M. D. Guiry (2004-09-23). "Laminaria agardhii Kjellman". AlgaeBase. 
  23. ^ Taylor (1957). Marine Algae of Northeastern Coast of North America. Ann Arbor. ISBN 0-472-04904-6. [page needed]
  24. ^ M. D. Guiry & Olga Selivanova (2006-09-19). "Laminaria appressirhiza J. E. Petrov & V. B. Vozzhinskaya". AlgaeBase. 
  25. ^ M. D. Guiry (2006-04-24). "Laminaria brongardiana Postels & Ruprecht". AlgaeBase. 
  26. ^ a b c I. A. Abbott & G. J. Hollenberg (1976). Marine Algae of California. Stanford University Press, Stanford, California. ISBN 0-8047-0867-3. [page needed]
  27. ^ H. Stegenga, J. J. Bolton & R. J. Anderson (1997). Seaweeds of the South Africal West Coast. Bolus Herbarium Number 18, University of Cape Town. 
  28. ^ Guiry, M. D. (2004-09-23). "Laminaria pallida Greville". AlgaeBase. National University of Ireland, Galway. 

External links[edit]