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Moenomycin Family Antibiotics
First described in 1965, the moenomycins are a family of phosphoglycolipid antibiotics, metabolites of the bacterial genus ''Streptomyces''. Moenomycin A is the founding member of the antibiotic family with the majority discovered by the end of the late 1970s. Structure The moenomycins can be reduced to three key structural features # A central 3-phosphoglyceric acid backbone. # A 25-carbon isoprenoid chain connected by an ether linkage to the C2-position of 3-phosphoglyceric acid. # A substituted tetrasaccharide tethered via a phosphodiester linkage to 3-phosphoglyceric acid. It is the combination of different isoprenoid chains and variously substituted tetrasaccharides that give rise to the diversity of the moenomycin family. Based on degradation experiments, the defining mark of a moenomycin is the presence of the 25-carbon alcohol moenocinol or diumycinol upon hydrolysis of the lipid tail; these alcohols originate from the L1 or L2 lipid respectively in the figure. These two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moenomycin A
First described in 1965, the moenomycins are a family of phosphoglycolipid antibiotics, metabolites of the bacterial genus ''Streptomyces''. Moenomycin A is the founding member of the antibiotic family with the majority discovered by the end of the late 1970s. Structure The moenomycins can be reduced to three key structural features # A central 3-phosphoglyceric acid backbone. # A 25-carbon isoprenoid chain connected by an ether linkage to the C2-position of 3-phosphoglyceric acid. # A substituted tetra saccharide tethered via a phosphodiester linkage to 3-phosphoglyceric acid. It is the combination of different isoprenoid chains and variously substituted tetrasaccharides that give rise to the diversity of the moenomycin family. Based on degradation experiments, the defining mark of a moenomycin is the presence of the 25-carbon alcohol moenocinol or diumycinol upon hydrolysis of the lipid tail; these alcohols originate from the L1 or L2 lipid respectively in the figure. These tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Engineering
Genetic engineering, also called genetic modification or genetic manipulation, is the modification and manipulation of an organism's genes using technology. It is a set of technologies used to change the genetic makeup of cells, including the transfer of genes within and across species boundaries to produce improved or novel organisms. New DNA is obtained by either isolating and copying the genetic material of interest using recombinant DNA methods or by artificially synthesising the DNA. A construct is usually created and used to insert this DNA into the host organism. The first recombinant DNA molecule was made by Paul Berg in 1972 by combining DNA from the monkey virus SV40 with the lambda virus. As well as inserting genes, the process can be used to remove, or "knock out", genes. The new DNA can be inserted randomly, or targeted to a specific part of the genome. An organism that is generated through genetic engineering is considered to be genetically modified (GM) an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antimicrobial Resistance
Antimicrobial resistance (AMR) occurs when microbes evolve mechanisms that protect them from the effects of antimicrobials. All classes of microbes can evolve resistance. Fungi evolve antifungal resistance. Viruses evolve antiviral resistance. Protozoa evolve antiprotozoal resistance, and bacteria evolve antibiotic resistance. Those bacteria that are considered extensively drug resistant (XDR) or totally drug-resistant (TDR) are sometimes called "superbugs".A.-P. Magiorakos, A. Srinivasan, R. B. Carey, Y. Carmeli, M. E. Falagas, C. G. Giske, S. Harbarth, J. F. Hinndler ''et al''Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria... Clinical Microbiology and Infection, Vol 8, Iss. 3 first published 27 July 2011 ia Wiley Online Library Retrieved 28 August 2020 Although antimicrobial resistance is a naturally-occurring process, it is often the result of improper usage of the drugs and management of the infections. Antibiotic resistance is a major subset o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bambermycins
Bambermycin (flavomycin) is a complex of antibiotics obtained from ''Streptomyces bambergiensis'' and ''Streptomyces ghanaensis'' used as a food additive for beef cattle, dairy cattle, poultry and swine. The complex consists mainly of moenomycins A and C. Bambermycin is a performance-enhancing antibiotic intended and available solely for use in animal nutrition. Its mechanism of action is to inhibit the synthesis of the bacterial wall The bacterium, despite its simplicity, contains a well-developed cell structure which is responsible for some of its unique biological structures and pathogenicity. Many structural features are unique to bacteria and are not found among archaea or .... Bambermycin is predominantly effective against Gram-positive pathogenic bacteria. However, it does not have significant action against '' Lactobacillus'', '' Bifidobacterium'', and other protective bacteria. Bambermycin has no precautions or warnings to humans on its label pertaining to mixin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-negative Bacteria
Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall sandwiched between an inner cytoplasmic cell membrane and a bacterial outer membrane. Gram-negative bacteria are found in virtually all environments on Earth that support life. The gram-negative bacteria include the model organism ''Escherichia coli'', as well as many pathogenic bacteria, such as ''Pseudomonas aeruginosa'', '' Chlamydia trachomatis'', and ''Yersinia pestis''. They are a significant medical challenge as their outer membrane protects them from many antibiotics (including penicillin), detergents that would normally damage the inner cell membrane, and lysozyme, an antimicrobial enzyme produced by animals that forms part of the innate immune system. Additionally, the outer leaflet of this membrane comprises a complex lipopol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minimum Inhibitory Concentration
In microbiology, the minimum inhibitory concentration (MIC) is the lowest concentration of a chemical, usually a drug, which prevents visible growth of a bacterium or bacteria. MIC depends on the microorganism, the affected human being (in vivo only), and the antibiotic itself. It is often expressed in micrograms per milliliter (μg/mL) or milligrams per liter (mg/L). The MIC is determined by preparing solutions of the chemical in vitro at increasing concentrations, incubating the solutions with separate batches of cultured bacteria, and measuring the results using agar dilution or broth microdilution. Results have been graded into susceptible (often called sensitive), increased exposure, or resistant to a particular antimicrobial by using a breakpoint. Breakpoints are agreed upon values, published in guidelines of a reference body, such as the U.S. Clinical and Laboratory Standards Institute (CLSI), the British Society for Antimicrobial Chemotherapy (BSAC) or the European Committee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-positive Bacteria
In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bacteria take up the crystal violet stain used in the test, and then appear to be purple-coloured when seen through an optical microscope. This is because the thick peptidoglycan layer in the bacterial cell wall retains the stain after it is washed away from the rest of the sample, in the decolorization stage of the test. Conversely, gram-negative bacteria cannot retain the violet stain after the decolorization step; alcohol used in this stage degrades the outer membrane of gram-negative cells, making the cell wall more porous and incapable of retaining the crystal violet stain. Their peptidoglycan layer is much thinner and sandwiched between an inner cell membrane and a bacterial outer membrane, causing them to take up the counterstain (sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycosyltransferases
Glycosyltransferases (GTFs, Gtfs) are enzymes ( EC 2.4) that establish natural glycosidic linkages. They catalyze the transfer of saccharide moieties from an activated nucleotide sugar (also known as the "glycosyl donor") to a nucleophilic glycosyl acceptor molecule, the nucleophile of which can be oxygen- carbon-, nitrogen-, or sulfur-based. The result of glycosyl transfer can be a carbohydrate, glycoside, oligosaccharide, or a polysaccharide. Some glycosyltransferases catalyse transfer to inorganic phosphate or water. Glycosyl transfer can also occur to protein residues, usually to tyrosine, serine, or threonine to give O-linked glycoproteins, or to asparagine to give N-linked glycoproteins. Mannosyl groups may be transferred to tryptophan to generate C-mannosyl tryptophan, which is relatively abundant in eukaryotes. Transferases may also use lipids as an acceptor, forming glycolipids, and even use lipid-linked sugar phosphate donors, such as dolichol phosphates in eukaryotic o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peptidoglycan
Peptidoglycan or murein is a unique large macromolecule, a polysaccharide, consisting of sugars and amino acids that forms a mesh-like peptidoglycan layer outside the plasma membrane, the rigid cell wall (murein sacculus) characteristic of most bacteria (domain ''Bacteria''). The sugar component consists of alternating residues of β-(1,4) linked ''N''-acetylglucosamine (NAG) and ''N''-acetylmuramic acid (NAM). Attached to the ''N''-acetylmuramic acid is a oligopeptide chain made of three to five amino acids. The peptide chain can be cross-linked to the peptide chain of another strand forming the 3D mesh-like layer. Peptidoglycan serves a structural role in the bacterial cell wall, giving structural strength, as well as counteracting the osmotic pressure of the cytoplasm. This repetitive linking results in a dense peptidoglycan layer which is critical for maintaining cell form and withstanding high osmotic pressures, and it is regularly replaced by peptidoglycan production. Pep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptomyces Ghanaensis
''Streptomyces viridosporus'' is a bacterium species from the genus of ''Streptomyces''.Deutsche Sammlung von Mikroorganismen und Zellkulturenbr>/ref> ''Streptomyces viridosporus'' produces sistomycine and lignin peroxidase. ''Streptomyces viridosporus'' can degrade lignin and humic acids. ''Streptomyces viridosporus'' also produces moenomycin A, a component of bambermycin.Deutsche Sammlung von Mikroorganismen und Zellkulturen The Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures GmbH (German: ''Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH''), located in Braunschweig, is a research infrastructure in th ...br>/ref> See also * List of Streptomyces species, List of ''Streptomyces'' species References Further reading * * * * * * * * * * * * * External linksType strain of ''Streptomyces viridosporus'' at Bac''Dive'' – the Bacterial Diversity Metadatabase viridosporus Bacteria descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrophosphate
In chemistry, pyrophosphates are phosphorus oxyanions that contain two phosphorus atoms in a P–O–P linkage. A number of pyrophosphate salts exist, such as disodium pyrophosphate (Na2H2P2O7) and tetrasodium pyrophosphate (Na4P2O7), among others. Often pyrophosphates are called diphosphates. The parent pyrophosphates are derived from partial or complete neutralization of pyrophosphoric acid. The pyrophosphate bond is also sometimes referred to as a phosphoanhydride bond, a naming convention which emphasizes the loss of water that occurs when two phosphates form a new P–O–P bond, and which mirrors the nomenclature for anhydrides of carboxylic acids. Pyrophosphates are found in ATP and other nucleotide triphosphates, which are important in biochemistry. The term pyrophosphate is also the name of esters formed by the condensation of a phosphorylated biological compound with inorganic phosphate, as for dimethylallyl pyrophosphate. This bond is also referred to as a high-energy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geranyl
Geraniol is a monoterpenoid and an alcohol. It is the primary component of citronella oil and is a primary component of rose oil, palmarosa oil. It is a colorless oil, although commercial samples can appear yellow. It has low solubility in water, but it is soluble in common organic solvents. The functional group derived from geraniol (in essence, geraniol lacking the terminal −OH) is called geranyl. Uses and occurrence In addition to rose oil, palmarosa oil, and citronella oil, it also occurs in small quantities in geranium, lemon, and many other essential oils. With a rose-like scent, it is commonly used in perfumes. It is used in flavors such as peach, raspberry, grapefruit, red apple, plum, lime, orange, lemon, watermelon, pineapple, and blueberry. Geraniol is produced by the scent glands of honeybees to mark nectar-bearing flowers and locate the entrances to their hives. It is also commonly used as an insect repellent, especially for mosquitoes. The scent of geraniol is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
