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M17 Agar
This bacterial growth medium was developed in 1971 for '' Lactococcus'' species isolated from milk products. It was originally called M16 medium, but in 1975 Terzaghi and Sandine added disodium- β-glycerophosphate to the medium as a buffer, and named the new growth medium M17 medium. It was later found that the addition of disodium-β-glycerophosphate inhibits the growth of many ''Lactobacillus'' species. Typical composition Per 950 mL: *5.0 g Pancreatic digest of casein *5.0 g Soy Peptone *5.0 g Beef extract *2.5 g Yeast extract *0.5 g Ascorbic acid *0.25 g Magnesium sulfate *19.0 g Disodium- β-glycerophosphate *11.0 g 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, t ... Preparation: *1. Heat with frequent agitation and boil for 1 minute to completely dissolve. *2. Aut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactococcus
''Lactococcus'', from Latin 'lac', meaning "milk", and Ancient Greek κόκκος (''kókkos''), meaning "sphere", is a genus of lactic acid bacteria that were formerly included in the genus ''Streptococcus'' Group N1. They are known as homofermenters meaning that they produce a single product, lactic acid in this case, as the major or only product of glucose fermentation. Their homofermentative character can be altered by adjusting environmental conditions such as pH, glucose concentration, and nutrient limitation. They are gram-positive, catalase-negative, non-motile cocci that are found singly, in pairs, or in chains. The genus contains strains known to grow at or below 7˚C. Twelve species of ''Lactococcus'' are currently recognized. They are: *'' Lactococcus allomyrinae'' *'' Lactococcus carnosus'' *'' Lactococcus chungangensis'' *'' Lactococcus cremoris'' **''L. cremoris'' subsp. ''cremoris'' **''L. cremoris'' subsp. ''tructae'' *'' Lactococcus formosensis'' **''L. formose ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycerol 2-phosphate
Glycerol 2-phosphate is the conjugate base of phosphoric ester of glycerol. It is commonly known as β-glycerophosphate or BGP. Unlike glycerol 1-phosphate and glycerol 3-phosphate, this isomer is not chiral. It is also less common. Applications β-Glycerophosphate is an inhibitor of the enzyme serine/threonine phosphatase. It is often used in combination with other phosphatase/protease inhibitors for broad spectrum inhibition. Although previously presumed to be non-transportable and reliant on extracellular phosphatases such as alkaline phosphatase (PhoA) for utilization, recent research indicates that ''Escherichia coli'' can use β-Glycerophosphate as a sole phosphorus source in the absence of PhoA, relying on the Ugp transporter system encoded by the ugpBAECQ operon. β-Glycerophosphate is also used to drive osteogenic differentiation of bone marrow stem cells ''in vitro''. β-Glycerophosphate is used to buffer M17 media for ''Lactococcus'' culture Culture ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tryptone
Tryptone is the assortment of peptides formed by the digestion of casein by the protease trypsin. Tryptone is commonly used in microbiology to produce lysogeny broth, lysogeny broth (LB) for the growth of ''Escherichia coli, E. coli'' and other microorganisms. It provides a source of amino acids for the growing bacteria. Tryptone is similar to casamino acids, both being digests of casein, but casamino acids can be produced by acid hydrolysis and typically only have free amino acids and few peptide chains; tryptone by contrast is the product of an incomplete enzymatic hydrolysis with some oligopeptides present. Tryptone is also a component of some germination media used in plant propagation.Pierik, R. L. M., et al. (1988)Seed germination and further development of plantlets of ''Paphiopedilum ciliolare'' Pfitz. ''in vitro''.''Scientia Horticulturae'', 34(1), 139-153. See also *wikt:albumose, Albumose *Trypticase soy agar References Peptides Microbiological media ingredien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peptone
Peptides are short chains of amino acids linked by peptide bonds. A polypeptide is a longer, continuous, unbranched peptide chain. Polypeptides that have a molecular mass of 10,000 Da or more are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. Peptides fall under the broad chemical classes of biological polymers and oligomers, alongside nucleic acids, oligosaccharides, polysaccharides, and others. Proteins consist of one or more polypeptides arranged in a biologically functional way, often bound to ligands such as coenzymes and cofactors, to another protein or other macromolecule such as DNA or RNA, or to complex macromolecular assemblies. Amino acids that have been incorporated into peptides are termed residues. A water molecule is released during formation of each amide bond.. All peptides except cyclic peptides have an N-terminal (amine group) and C-terminal (carboxyl group) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beef Extract
Meat extract is highly concentrated meat stock, usually made from beef or chicken. It is used to add meat flavor in cooking, and to make broth for soups and other liquid-based foods. Meat extract was invented by Baron Justus von Liebig, a German 19th-century organic chemist. Liebig specialised in chemistry and the classification of food and wrote a paper on how the nutritional value of a meat is lost by boiling. Liebig's view was that meat juices, as well as the fibres, contained much important nutritional value and that these were lost by boiling or cooking in unenclosed vessels. Fuelled by a desire to help feed the undernourished, in 1840 he developed a concentrated beef extract, ''Extractum carnis Liebig'', to provide a nutritious meat substitute for those unable to afford the real thing. However, it took 30 kg of meat to produce 1 kg of extract, making the extract too expensive. Commercialization Liebig's Extract of Meat Company Liebig went on to co-found the L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yeast Extract
Yeast extracts consist of the cell contents of yeast without the cell walls; they are used as food additives or flavorings, or as nutrients for bacterial culture Growing media, media. They are often used to create savoury flavors and umami taste sensations and can be found in a large variety of packaged foods including frozen meals, crackers, snack foods, gravy, stock and more. They are rich in B vitamins (but not Vitamin B12, B12). Yeast extracts and Fermentation in food processing, fermented foods contain glutamic acid (free glutamates), an amino acid which adds an umami flavor. Glutamic acid is found in meat, cheese, fungi (mushrooms and yeast) and vegetables—such as broccoli and tomatoes. A number of other substances found in yeast extract provide aromas, some meat-like, when allowed to react under heat. The heat-autolytic process to make yeast extract of the autolysate type was invented in the 19th century by Justus von Liebig. Yeast cells are heated until they rupture, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ascorbic Acid
Ascorbic acid is an organic compound with formula , originally called hexuronic acid. It is a white solid, but impure samples can appear yellowish. It dissolves freely in water to give mildly acidic solutions. It is a mild reducing agent. Ascorbic acid exists as two enantiomers (mirror-image isomers), commonly denoted "" (for "levo") and "" (for "dextro"). The isomer is the one most often encountered: it occurs naturally in many foods, and is one form (" vitamer") of vitamin C, an essential nutrient for humans and many animals. Deficiency of vitamin C causes scurvy, formerly a major disease of sailors in long sea voyages. It is used as a food additive and a dietary supplement for its antioxidant properties. The "" form ( erythorbic acid) can be made by chemical synthesis, but has no significant biological role. Etymology The term ''ascorbic'' means antiscruvy and denotes the ability to fight off scurvy. It is related to combating Vitamin C deficiency. History The antiscor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnesium Sulfate
Magnesium sulfate or magnesium sulphate is a chemical compound, a salt with the formula , consisting of magnesium cations (20.19% by mass) and sulfate anions . It is a white crystalline solid, soluble in water but not in ethanol. Magnesium sulfate is usually encountered in the form of a hydrate , for various values of ''n'' between 1 and 11. The most common is the heptahydrate , known as Epsom salt, which is a household chemical with many traditional uses, including bath salts. The main use of magnesium sulfate is in agriculture, to correct soils deficient in magnesium (an essential plant nutrient because of the role of magnesium in chlorophyll and photosynthesis). The monohydrate is favored for this use; by the mid 1970s, its production was 2.3 million tons per year. The anhydrous form and several hydrates occur in nature as minerals, and the salt is a significant component of the water from some springs. Hydrates Magnesium sulfate can crystallize as several hy ... [...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" 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] |
