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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" and " tengusa". 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 desserts; as a clarifying ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agarose
Agarose is a heteropolysaccharide, generally extracted from certain red algae. It is a linear polymer made up of the repeating unit of agarobiose, which is a disaccharide made up of D-galactose and 3,6-anhydro-L-galactopyranose. Agarose is one of the two principal components of agar, and is purified from agar by removing agar's other component, agaropectin. Agarose is frequently used in molecular biology for the separation of large molecules, especially DNA, by electrophoresis. Slabs of agarose gels (usually 0.7 - 2%) for electrophoresis are readily prepared by pouring the warm, liquid solution into a mold. A wide range of different agaroses of varying molecular weights and properties are commercially available for this purpose. Agarose may also be formed into beads and used in a number of chromatographic methods for protein purification. Structure Agarose is a linear polymer with a molecular weight of about 120,000, consisting of alternating D- galactose and 3,6-an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Growth Medium
A growth medium or culture medium is a solid, liquid, or semi-solid designed to support the growth of a population of microorganisms or cells via the process of cell proliferation or small plants like the moss ''Physcomitrella patens''. Different types of media are used for growing different types of cells. The two major types of growth media are those used for cell culture, which use specific cell types derived from plants or animals, and those used for microbiological culture, which are used for growing microorganisms such as bacteria or fungi. The most common growth media for microorganisms are nutrient broths and agar plates; specialized media are sometimes required for microorganism and cell culture growth. Some organisms, termed fastidious organisms, require specialized environments due to complex nutritional requirements. Viruses, for example, are obligate intracellular parasites and require a growth medium containing living cells. Types The most common growth media ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agaropectin
Agaropectin is one of the two main components of agar. Structure Agaropectin is a sulfated galactan mixture which composes agar by 30% composition. It is composed of varying percentages of organosulfates (sulfate esters), D-glucuronic acid and small amounts of pyruvic acid. It is made up of alternating units of D-galactose and L-galactose heavily modified with acidic side-groups which are usually sulfate, glucuronate, and pyruvate. Pyruvic acid is possibly attached in an acetal form to the D-galactose residues of the agarobiose skeleton. The sulfate content of the agar depends on the source of the raw material from which it is derived. Acetylation of agaropectin yields the chloroform-insoluble agaropectin acetate, as opposed to agarose acetate. This process can be used to separate the two polysaccharides via fractionation Fractionation is a separation process in which a certain quantity of a mixture (of gasses, solids, liquids, enzymes, or isotopes, or a suspension) is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhodophyta
Red algae, or Rhodophyta (, ; ), make up one of the oldest groups of eukaryotic algae. The Rhodophyta comprises one of the largest phyla of algae, containing over 7,000 recognized species within over 900 genera amidst ongoing taxonomic revisions. The majority of species (6,793) are Florideophyceae, and mostly consist of multicellular, marine algae, including many notable seaweeds. Red algae are abundant in marine habitats. Approximately 5% of red algae species occur in freshwater environments, with greater concentrations in warmer areas. Except for two coastal cave dwelling species in the asexual class Cyanidiophyceae, no terrestrial species exist, 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. Red algae form a distinct group characterized by eukaryotic cells without flagella and centrioles, chloroplasts without external endoplasmic reticulum or unstacked (stroma) thylako ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gracilaria Edulis
''Gracilaria'', also known as irish moss or ogonori, is a genus of red algae in the family Gracilariaceae. It is notable for its economic importance as an agarophyte meaning that it is used to make agar, 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. They produce over 90% of the world's agar. 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Algae
Red algae, or Rhodophyta (, ; ), make up one of the oldest groups of eukaryotic algae. The Rhodophyta comprises one of the largest Phylum, phyla of algae, containing over 7,000 recognized species within over 900 Genus, genera amidst ongoing taxonomic revisions. The majority of species (6,793) are Florideophyceae, and mostly consist of multicellular, ocean, marine algae, including many notable seaweeds. Red algae are abundant in marine habitats. Approximately 5% of red algae species occur in freshwater environments, with greater concentrations in warmer areas. Except for two coastal cave dwelling species in the asexual class Cyanidiophyceae, no terrestrial species exist, 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. Red algae form a distinct group characterized by eukaryotic cells without flagella and centrioles, chloroplasts without external endoplasmic reticulum or unstack ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gracilaria
''Gracilaria'', also known as irish moss or ogonori, is a genus of red algae in the family Gracilariaceae. It is notable for its economic importance as an agarophyte meaning that it is used to make agar, 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. They produce over 90% of the world's agar. 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agarophyte
An agarophyte is a seaweed, usually 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'' (such as ''Gelidium amansii'' and ''Gelidium corneum''). References Seaweeds {{Rhodophyta-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dessert
Dessert is a course (food), course that concludes a meal; the course consists of sweet foods, such as cake, biscuit, ice cream, and possibly a beverage, such as dessert wine or liqueur. Some cultures sweeten foods that are more commonly umami, savory to create desserts. In some parts of the world, there is no tradition of a dessert course to conclude a meal. Historically, the dessert course consisted entirely of foods 'from the storeroom' (''de l’office''), including fresh, stewed, preserved, and dried fruits; nuts; cheese and other dairy dishes; Cookie, dry biscuits (cookies) and wafers; and ices and Ice cream, ice creams. Sweet dishes from the kitchen, such as freshly prepared pastries, meringues, custards, puddings, and baked fruits, were served in the Entremet, entremets course, not in the dessert course. By the 20th century, though, sweet entremets had come to be included among the desserts. The modern term ''dessert'' can apply to many sweets, including fruit, custard ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tokoroten
is a gelatinous dish in Japanese cuisine, made from agarophyte seaweed. It was traditionally made by boiling ''tengusa'' (''Gelidium amansii'') and allowing the mixture to congeal into a jelly. The jelly is then pressed through an extruding device and shaped into noodles. Unlike gelatin desserts, ''tokoroten'' has a firmer texture. ''Tokoroten'' can be eaten hot (in solution) or cold (as a gel). Flavorings and garnishes can vary from region to region. In the present day, it is common to eat it with a mixture of vinegar and soy sauce, and sometimes nori, hot pepper, or sesame. In the Kansai region, ''tokoroten'' is eaten as a dessert with ''kuromitsu'' syrup. History ''Tokoroten'' has been eaten in Japan for over a thousand years. It is thought to have been introduced to Japan from China during the Nara period. During the Edo period, it was popular during the summer as a snack. It was originally made to be eaten immediately and was commonly sold around factories. In the 17 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Substrate (biology)
In biology, a substrate is the surface on which an organism (such as a plant, fungus, or animal) lives. A substrate can include biotic or abiotic materials and animals. For example, encrusting algae that lives on a rock (its substrate) can be itself a substrate for an animal that lives on top of the algae. Inert substrates are used as growing support materials in the hydroponic cultivation of plants. In biology substrates are often activated by the nanoscopic process of substrate presentation. In agriculture and horticulture * Cellulose substrate * Expanded clay aggregate (LECA) * Rock wool * Potting soil * Soil In animal biotechnology Requirements for animal cell and tissue culture Requirements for animal cell and tissue culture are the same as described for plant cell, tissue and organ culture (In Vitro Culture Techniques: The Biotechnological Principles). Desirable requirements are (i) air conditioning of a room, (ii) hot room with temperature recorder, (iii) microsc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southeast Asia
Southeast Asia is the geographical United Nations geoscheme for Asia#South-eastern Asia, southeastern region of Asia, consisting of the regions that are situated south of China, east of the Indian subcontinent, and northwest of the Mainland Australia, Australian mainland, which is part of Oceania. Southeast Asia is bordered to the north by East Asia, to the west by South Asia and the Bay of Bengal, to the east by Oceania and the Pacific Ocean, and to the south by Australia (continent), Australia and the Indian Ocean. Apart from the British Indian Ocean Territory and two out of Atolls of the Maldives, 26 atolls of the Maldives in South Asia, Maritime Southeast Asia is the only other subregion of Asia that lies partly within the Southern Hemisphere. Mainland Southeast Asia is entirely in the Northern Hemisphere. Timor-Leste and the southern portion of Indonesia are the parts of Southeast Asia that lie south of the equator. The region lies near the intersection of Plate tectonics, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
