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Agarophyte
An agarophyte is a seaweed, typically a red alga, that produces the hydrocolloid agar in its cell walls. This agar can be harvested commercially for use in biological experiments and culturing. In some countries (especially in the developing world), the harvesting of agarophytes, either as natural stocks or a cultivated crop, is of considerable economic importance. Notable genera of commercially exploited agarophytes include ''Gracilaria'' and ''Gelidium ''Gelidium'' is a genus of thalloid red algae comprising 134 species. Its members are known by a number of common names.Recorded common names are tengusa, makusa, genso, niu mau tsai, japansche scheleiachtige mos, steen-or klipbloem, hay tsay, ol ...'' (such as ''Gelidium amansii'' and ''Gelidium corneum''). References Seaweeds {{Rhodophyta-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gelidium
''Gelidium'' is a genus of thalloid red algae comprising 134 species. Its members are known by a number of common names.Recorded common names are tengusa, makusa, genso, niu mau tsai, japansche scheleiachtige mos, steen-or klipbloem, hay tsay, olus marinus, sajur laut, tschintschau, tschoo-hoae, onikusa, hirakusa, obusa, rødalge-slaegt, gelídeos, punalevä-suku, tokoroten, kanten, tokoro-tengusa, kinukusa, isingglass, hai-ten-gusa, tocoroten, tengusa-agar, limu lo-loa, hai-tengusa, onigusa, oyakusa, kanten weed, goumaocai, hime tengusa, shihua and tanmae. Taxonomy and Nomenclature Gelidiaceae has 159 species, considered to be the largest family in Gelidiales with four major genera: ''Capreolia, Gelidium, Gelidiophycus,'' and ''Ptilophora'.'' ''Gelidium'' was first described by Lamouroux in 1813 and is regarded to be one the genus with the most species. Species diversity has been established by previous studies, whereas, molecular analysis reveals biogeographic relations that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agar
Agar ( or ), or agar-agar, is a jelly-like substance consisting of polysaccharides obtained from the cell walls of some species of red algae, primarily from ogonori (''Gracilaria'') and "tengusa" (''Gelidiaceae''). As found in nature, agar is a mixture of two components, the linear polysaccharide agarose and a heterogeneous mixture of smaller molecules called agaropectin. It forms the supporting structure in the cell walls of certain species of algae and is released on boiling. These algae are known as agarophytes, belonging to the Rhodophyta (red algae) phylum. The processing of food-grade agar removes the agaropectin, and the commercial product is essentially pure agarose. Agar has been used as an ingredient in desserts throughout Asia and also as a solid substrate to contain culture media for microbiological work. Agar can be used as a laxative; an appetite suppressant; a vegan substitute for gelatin; a thickener for soups; in fruit preserves, ice cream, and other desser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gracilaria
''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 within the genus are cultivated among Asia, South America, Africa and Oceania. Taxonomy ''Gracilaria'' contains the following subtaxa: *'' Gracilaria abbottiana'' M.D.Hoyle *'' Gracilaria abyssalis'' Gurgel & Yoneshigue-Valentin *'' Gracilaria aculeata'' (Hering) Papenfuss *'' Gracilaria aggregata'' Hooker f. & Harvey *'' Gracilaria ambigua'' Greville *'' Gracilaria apiculata'' P.Crouan & H.Crouan ** ''Gracilaria apiculata'' subsp. ''candelabriformis'' Gurgel, Fredericq & J.N.Norris *'' Gracilaria apiculifera'' J.Agardh ** ''Gracilaria arcuata'' f. ''rhizophora'' Børgesen ** ''Gracilaria arcuata'' var. ''attenuata'' Umamaheswara Rao ** ''Gracilaria arcuata'' var. ''snackeyi'' Weber Bosse *'' Gracilaria arcuata'' Zanardini *'' Gracilaria armata'' (C.Agardh) Greville *'' Gracilaria artic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seaweed
Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of '' Rhodophyta'' (red), ''Phaeophyta'' (brown) and ''Chlorophyta'' (green) macroalgae. Seaweed species such as kelps provide essential nursery habitat for fisheries and other marine species and thus protect food sources; other species, such as planktonic algae, play a vital role in capturing carbon, producing at least 50% of Earth's oxygen. Natural seaweed ecosystems are sometimes under threat from human activity. For example, mechanical dredging of kelp destroys the resource and dependent fisheries. Other forces also threaten some seaweed ecosystems; a wasting disease in predators of purple urchins has led to a urchin population surge which destroyed large kelp forest regions off the coast of California. Humans have a long history of cultivating seaweeds for their uses. In recent years, seaweed farming has become a global agricultural practic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Alga
Red algae, or Rhodophyta (, ; ), are one of the oldest groups of eukaryotic algae. The Rhodophyta also 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 (biology), class), and mostly consist of multicellular, ocean, marine algae, including many notable seaweed, 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. The red algae form a distinct group characterized by having eukaryotic cells without flagella and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrocolloid
A colloid is a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance. Some definitions specify that the particles must be dispersed in a liquid, while others extend the definition to include substances like aerosols and gels. The term colloidal suspension refers unambiguously to the overall mixture (although a narrower sense of the word ''suspension'' is distinguished from colloids by larger particle size). A colloid has a dispersed phase (the suspended particles) and a continuous phase (the medium of suspension). The dispersed phase particles have a diameter of approximately 1 nanometre to 1 micrometre. Some colloids are translucent because of the Tyndall effect, which is the scattering of light by particles in the colloid. Other colloids may be opaque or have a slight color. Colloidal suspensions are the subject of interface and colloid science. This field of study was introduced in 1845 by Italian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Wall
A cell wall is a structural layer surrounding some types of cells, just outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides the cell with both structural support and protection, and also acts as a filtering mechanism. Cell walls are absent in many eukaryotes, including animals, but are present in some other ones like fungi, algae and plants, and in most prokaryotes (except mollicute bacteria). A major function is to act as pressure vessels, preventing over-expansion of the cell when water enters. The composition of cell walls varies between taxonomic group and species and may depend on cell type and developmental stage. The primary cell wall of land plants is composed of the polysaccharides cellulose, hemicelluloses and pectin. Often, other polymers such as lignin, suberin or cutin are anchored to or embedded in plant cell walls. Algae possess cell walls made of glycoproteins and polysaccharides such as carrageenan and agar that are absent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
