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Azomonas Agilis
''Azomonas agilis'' is a species of motile, Gram-negative bacteria found in water and is capable of fixing atmospheric nitrogen. It is the type strain for the genus ''Azomonas''. ''A. agilis'' resembles protists with its ovoid, ellipsoidal, or coccoid cells. The cells are relatively large, usually 2.5-6.4 μm long and 2.0-2.8 μm wide, though giant cells that are 10.0-13.5 μm have been described. The cells have peritrichous flagella which enable motility. The species also produces a diffusible yellow-green or red-violet pigment which fluoresces bluish-white under ultraviolet light. ''A. agilis'' was first isolated and described by Martinus Beijerinck in 1901, who obtained the species from Dutch canal water in Delft. Beijernick's original strain has been lost, so the strain isolated by Albert Kluyver and van den Bout is now the neotype. Despite the fact that mannitol was used by Beijerinck in his enrichment medium for ''A. agilis'', the bacteria in pure culture cannot use it as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Bacteria also live in symbiotic and parasitic relationsh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flagellum
A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates. A microorganism may have from one to many flagella. A gram-negative bacterium ''Helicobacter pylori'' for example uses its multiple flagella to propel itself through the mucus lining to reach the stomach epithelium, where it may cause a gastric ulcer to develop. In some bacteria the flagellum can also function as a sensory organelle, being sensitive to wetness outside the cell. Across the three domains of Bacteria, Archaea, and Eukaryota the flagellum has a different structure, protein composition, and mechanism of propulsion but shares the same function of providing motility. The Latin word means " whip" to describe its lash-like swimming motion. The flagellum in archaea is called the archaellum to note its difference from the bacterial flagellum. Eukaryotic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioremediation
Bioremediation broadly refers to any process wherein a biological system (typically bacteria, microalgae, fungi, and plants), living or dead, is employed for removing environmental pollutants from air, water, soil, flue gasses, industrial effluents etc., in natural or artificial settings. The natural ability of organisms to adsorb, accumulate, and degrade common and emerging pollutants has attracted the use of biological resources in treatment of contaminated environment. In comparison to conventional physicochemical treatment methods bioremediation may offer considerable advantages as it aims to be sustainable, eco-friendly, cheap, and scalable. Most bioremediation is inadvertent, involving native organisms. Research on bioremediation is heavily focused on stimulating the process by inoculation of a polluted site with organisms or supplying nutrients to promote the growth. In principle, bioremediation could be used to reduce the impact of byproducts created from anthropogenic acti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iodoacetate
Iodoacetic acid is a derivative of acetic acid. It is a toxic compound, because, like many alkyl halides, it is an alkylating agent. It reacts with cysteine residues in proteins. It is often used to modify SH-groups to prevent the re-formation of disulfide bonds after the reduction of cystine residues to cysteine during protein sequencing. Peptidase inhibitor Iodoacetate is an irreversible inhibitor of all cysteine peptidases, with the mechanism of inhibition occurring from alkylation of the catalytic cysteine residue (see schematic). In comparison with its amide derivative, iodoacetamide, iodoacetate reacts substantially slower. This observation appears contradictory to standard chemical reactivity, however the presence of a favourable interaction between the positive imidazolium ion of the catalytic histidine and the negatively charged carboxyl-group of the iodoacetic acid is the reason for the increased activity of iodoacetamide. Possible cancer therapy Several studies hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mannitol
Mannitol is a type of sugar alcohol used as a sweetener and medication. It is used as a low calorie sweetener as it is poorly absorbed by the intestines. As a medication, it is used to decrease pressure in the eyes, as in glaucoma, and to lower increased intracranial pressure. Medically, it is given by injection or inhalation. Effects typically begin within 15 minutes and last up to 8 hours. Common side effects from medical use include electrolyte problems and dehydration. Other serious side effects may include worsening heart failure and kidney problems. It is unclear if use is safe in pregnancy. Mannitol is in the osmotic diuretic family of medications and works by pulling fluid from the brain and eyes. The discovery of mannitol is attributed to Joseph Louis Proust in 1806. It is on the World Health Organization's List of Essential Medicines. It was originally made from the flowering ash and called manna due to its supposed resemblance to the Biblical food. Mannitol is on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albert Kluyver
Albert Jan Kluyver ForMemRS (June 3, 1888 – May 14, 1956) was a Dutch microbiologist and biochemist. Career In 1926, Kluyver and Hendrick Jean Louis Donker published the now classic paper, "Die Einheit in der Biochemie" ("Unity in Biochemistry"). The paper helped establish Kluyver's vision that, at a biochemical level, all organisms are unified. Kluyver famously expressed the idea with the aphorism: "From elephant to butyric acid bacterium – it is all the same". The paper, and other work from Kluyver's lab, helped support both the concept of biochemical unity as well as the idea of "comparative biochemistry", which Kluyver envisioned as biochemically equivalent to comparative anatomy. The concept established a theoretical basis for studying chemical processes in bacteria and extrapolating those processes to higher organisms. The concepts of "biochemical unity" and "comparative biochemistry" were both very influential and probably Kluyver's most significant work. Kluyver's b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delft
Delft () is a List of cities in the Netherlands by province, city and Municipalities of the Netherlands, municipality in the Provinces of the Netherlands, province of South Holland, Netherlands. It is located between Rotterdam, to the southeast, and The Hague, to the northwest. Together with them, it is part of both the Rotterdam–The Hague metropolitan area and the Randstad. Delft is a popular tourist destination in the Netherlands, famous for its historical connections with the reigning House of Orange-Nassau, for its Delftware, blue pottery, for being home to the painter Johannes Vermeer, Jan Vermeer, and for hosting Delft University of Technology (TU Delft). Historically, Delft played a highly influential role in the Dutch Golden Age. In terms of science and technology, thanks to the pioneering contributions of Antonie van Leeuwenhoek and Martinus Beijerinck, Delft can be considered to be the birthplace of microbiology. History Early history The city of Delft came into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Martinus Beijerinck
Martinus Willem Beijerinck (, 16 March 1851 – 1 January 1931) was a Dutch microbiologist and botanist who was one of the founders of virology and environmental microbiology. He is credited with the discovery of viruses, which he called "''contagium vivum fluidum''". Life Early life and education Born in Amsterdam, Beijerinck studied at the Technical School of Delft, where he was awarded the degree of Chemical Engineer in 1872. He obtained his Doctor of Science degree from the University of Leiden in 1877. At the time, Delft, then a Polytechnic, did not have the right to confer doctorates, so Leiden did this for them. He became a teacher in microbiology at the Agricultural School in Wageningen (now Wageningen University) and later at the ''Polytechnische Hogeschool Delft'' (Delft Polytechnic, currently Delft University of Technology) (from 1895). He established the Delft School of Microbiology. His studies of agricultural and industrial microbiology yielded fundamental disco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultraviolet
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nanometer, nm (with a corresponding frequency around 30 Hertz, PHz) to 400 nm (750 Hertz, THz), shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight, and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack the energy to ionization, ionize atoms, it can cause chemical reactions and causes many substances to glow or fluorescence, fluoresce. Consequently, the chemical and biological effects of UV are greater than simple heating effects, and many practical applications of UV radiation derive from its interactions with organic molecules. Short-wave ultraviolet light damages DNA and sterilizes surf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seventh in total abundance in the Milky Way and the Solar System. At standard temperature and pressure, two atoms of the element bond to form N2, a colorless and odorless diatomic gas. N2 forms about 78% of Earth's atmosphere, making it the most abundant uncombined element. Nitrogen occurs in all organisms, primarily in amino acids (and thus proteins), in the nucleic acids ( DNA and RNA) and in the energy transfer molecule adenosine triphosphate. The human body contains about 3% nitrogen by mass, the fourth most abundant element in the body after oxygen, carbon, and hydrogen. The nitrogen cycle describes the movement of the element from the air, into the biosphere and organic compounds, then back into the atmosphere. Many indus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudomonadota
Pseudomonadota (synonym Proteobacteria) is a major phylum of Gram-negative bacteria. The renaming of phyla in 2021 remains controversial among microbiologists, many of whom continue to use the earlier names of long standing in the literature. The phylum Proteobacteria includes a wide variety of pathogenic genera, such as ''Escherichia'', '' Salmonella'', ''Vibrio'', ''Yersinia'', ''Legionella'', and many others.Slonczewski JL, Foster JW, Foster E. Microbiology: An Evolving Science 5th Ed. WW Norton & Company; 2020. Others are free-living (nonparasitic) and include many of the bacteria responsible for nitrogen fixation. Carl Woese established this grouping in 1987, calling it informally the "purple bacteria and their relatives". Because of the great diversity of forms found in this group, it was later informally named Proteobacteria, after Proteus, a Greek god of the sea capable of assuming many different shapes (not after the Proteobacteria genus ''Proteus''). In 2021 the Internat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen Fixation
Nitrogen fixation is a chemical process by which molecular nitrogen (), with a strong triple covalent bond, in the air is converted into ammonia () or related nitrogenous compounds, typically in soil or aquatic systems but also in industry. Atmospheric nitrogen is molecular dinitrogen, a relatively nonreactive molecule that is metabolically useless to all but a few microorganisms. Biological nitrogen fixation or ''diazotrophy'' is an important microbials mediated process that converts dinitrogen (N2) gas to ammonia (NH3) using the nitrogenase protein complex (Nif). Nitrogen fixation is essential to life because fixed inorganic nitrogen compounds are required for the biosynthesis of all nitrogen-containing organic compounds, such as amino acids and proteins, nucleoside triphosphates and nucleic acids. As part of the nitrogen cycle, it is essential for agriculture and the manufacture of fertilizer. It is also, indirectly, relevant to the manufacture of all nitrogen chemical c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
