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Metallotolerants
Metallotolerants are extremophile organisms that are able to survive in environments with a high concentration of dissolved heavy metals. They can be found in environments containing arsenic, cadmium, copper, and zinc. Known metallotolerants include ''Ferroplasma'' sp. and ''Cupriavidus metallidurans''. Metallotolerants adapt to their environment by reducing energy loss by excreting less. ''Sinorhizobium ''Ensifer'' (often referred to in literature by its synonym ''Sinorhizobium'') is a genus of nitrogen-fixing bacteria ( rhizobia), three of which ('' Ensifer meliloti'', ''Ensifer medicae'' and '' Ensifer fredii'') have been sequenced. Etymolo ... sp. M14'' is a metallotolerant bacterium. References * {{microbiology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cupriavidus Metallidurans
''Cupriavidus metallidurans'' is a non-spore-forming, Gram-negative bacterium which is adapted to survive several forms of heavy metal stress. As a model and industrial system It is an ideal subject to study heavy metal disturbance of cellular processes. This bacterium shows a unique combination of advantages not present in this form in other bacteria. * Its genome (strain CH34) has been fully sequenced (preliminary, annotated sequence data were obtained from the DOE Joint Genome Institute) * It is not pathogenic, therefore, models of the cell can also be tested in artificial environments similar to its natural habitats. * It is related to the plant pathogen '' Ralstonia solanacearum''. * It is of ecological importance since related bacteria are predominant in mesophilic heavy metal-contaminated environments. * It is of industrial importance and used for heavy metal remediation and sensing. * It is an aerobic chemolithoautotroph, facultatively able to grow in a mineral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferroplasma
''Ferroplasma'' is a genus of Archaea that belong to the family Ferroplasmaceae. Members of the ''Ferroplasma'' are typically acidophillic, pleomorphic, irregularly shaped cocci. The archaean family Ferroplasmaceae was first described in the early 2000s. To date very few species of ''Ferroplasma'' have been isolated and characterized. Isolated species include ''Ferroplasma acidiphilum'', ''Ferroplasma acidarmanus,'' and ''Ferroplasma thermophilum''. A fourth isolate ''Ferroplasma cupricumulans'' was later determined to belong to a separate genus''.'' All known ''Ferroplasma sp.'' are iron-oxidizers. Cell characteristics and Physiology ''Ferroplasma'' cells are pleomorphic and lack a cell-wall. All known members of the genera are acidophiles that thrive in environments where pH ranges from 0.0 to 2.0. They are also mesophilic to moderately thermophilic with optimal temperatures ranging from 35-55 °C. Tetraether-based lipids are an important part of the ''Ferroplasma'' cel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extremophile
An extremophile (from Latin ' meaning "extreme" and Greek ' () meaning "love") is an organism that is able to live (or in some cases thrive) in extreme environments, i.e. environments that make survival challenging such as due to extreme temperature, radiation, salinity, or pH level. These organisms are ecologically dominant in the evolutionary history of the planet. Some spores and cocooned bacteria samples have been dormant for more than 40 million years, extremophiles have continued to thrive in the most extreme conditions, making them one of the most abundant lifeforms. Characteristics In the 1980s and 1990s, biologists found that microbial life has great flexibility for surviving in extreme environments—niches that are acidic, extraordinarily hot or within irregular air pressure for example—that would be completely inhospitable to complex organisms. Some scientists even concluded that life may have begun on Earth in hydrothermal vents far under the ocean's surfa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organism
In biology, an organism () is any living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are classified by taxonomy into groups such as multicellular animals, plants, and fungi; or unicellular microorganisms such as protists, bacteria, and archaea. All types of organisms are capable of reproduction, growth and development, maintenance, and some degree of response to stimuli. Beetles, squids, tetrapods, mushrooms, and vascular plants are examples of multicellular organisms that differentiate specialized tissues and organs during development. A unicellular organism may be either a prokaryote or a eukaryote. Prokaryotes are represented by two separate domains – bacteria and archaea. Eukaryotic organisms are characterized by the presence of a membrane-bound cell nucleus and contain additional membrane-bound compartments called organelles (such as mitochondria in animals and plants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heavy Metal (chemistry)
upright=1.2, Crystals of osmium, a heavy metal nearly twice as dense as lead">lead.html" ;"title="osmium, a heavy metal nearly twice as dense as lead">osmium, a heavy metal nearly twice as dense as lead Heavy metals are generally defined as metals with relatively high density, densities, atomic weights, or atomic numbers. The criteria used, and whether metalloids are included, vary depending on the author and context. In metallurgy, for example, a heavy metal may be defined on the basis of density, whereas in physics the distinguishing criterion might be atomic number, while a chemist would likely be more concerned with chemical property, chemical behaviour. More specific definitions have been published, but none of these have been widely accepted. The definitions surveyed in this article encompass up to 96 out of the 118 known chemical elements; only mercury, lead and bismuth meet all of them. Despite this lack of agreement, the term (plural or singular) is widely used in s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arsenic
Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, but only the gray form, which has a metallic appearance, is important to industry. The primary use of arsenic is in alloys of lead (for example, in car batteries and ammunition). Arsenic is a common n-type dopant in semiconductor electronic devices. It is also a component of the III-V compound semiconductor gallium arsenide. Arsenic and its compounds, especially the trioxide, are used in the production of pesticides, treated wood products, herbicides, and insecticides. These applications are declining with the increasing recognition of the toxicity of arsenic and its compounds. A few species of bacteria are able to use arsenic compounds as respiratory metabolites. Trace quantities of arsenic are an essential dietary element in rats, ham ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cadmium
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Like zinc, it demonstrates oxidation state +2 in most of its compounds, and like mercury, it has a lower melting point than the transition metals in groups 3 through 11. Cadmium and its congeners in group 12 are often not considered transition metals, in that they do not have partly filled ''d'' or ''f'' electron shells in the elemental or common oxidation states. The average concentration of cadmium in Earth's crust is between 0.1 and 0.5 parts per million (ppm). It was discovered in 1817 simultaneously by Stromeyer and Hermann, both in Germany, as an impurity in zinc carbonate. Cadmium occurs as a minor component in most zinc ores and is a byproduct of zinc production. Cadmium was used for a long time as a corrosion-resistant plating on steel, and cadmium compounds are used as red, orang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper
Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement. Copper is one of the few metals that can occur in nature in a directly usable metallic form ( native metals). This led to very early human use in several regions, from circa 8000 BC. Thousands of years later, it was the first metal to be smelted from sulfide ores, circa 5000 BC; the first metal to be cast into a shape in a mold, c. 4000 BC; and the first metal to be purposely alloyed with another metal, tin, to create ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zinc
Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic table. In some respects, zinc is chemically similar to magnesium: both elements exhibit only one normal oxidation state (+2), and the Zn2+ and Mg2+ ions are of similar size.The elements are from different metal groups. See periodic table. Zinc is the 24th most abundant element in Earth's crust and has five stable isotopes. The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral. The largest workable lodes are in Australia, Asia, and the United States. Zinc is refined by froth flotation of the ore, roasting, and final extraction using electricity ( electrowinning). Zinc is an essential trace element for humans, animals, plants and for microorganisms and is necessary for prenatal and postnatal development. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinorhizobium
''Ensifer'' (often referred to in literature by its synonym ''Sinorhizobium'') is a genus of nitrogen-fixing bacteria ( rhizobia), three of which ('' Ensifer meliloti'', ''Ensifer medicae'' and '' Ensifer fredii'') have been sequenced. Etymology The generic epithet ''Ensifer'' derives from the Latin noun ''ensifer'', "sword-bearer". The synonym ''Sinorhizobium'' is a combination of Medieval Latin noun ''sino'' ("China"), the Classical Greek noun ''rhiza'' ("root"), and the Classical Greek noun ''bium'' ("life"). Thus, the Neo-Latin generic epithet of the synonym ''Sinorhizobium'' means "a ''Rhizobium'' isolated from China", in turn referring to the related genus '' Rhizobium'' ("root-associated life form"). Proper name The name ''Ensifer'' was published in 1982 and the name ''Sinorhizobium'' was published in 1988 thus the latter is regarded as a later synonym and by the rules of the Bacteriological Code (1990 Revision) of the International Committee on Systematics of Prokaryote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metals
A metal (from Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typically ductile (can be drawn into wires) and malleable (they can be hammered into thin sheets). These properties are the result of the ''metallic bond'' between the atoms or molecules of the metal. A metal may be a chemical element such as iron; an alloy such as stainless steel; or a molecular compound such as polymeric sulfur nitride. In physics, a metal is generally regarded as any substance capable of conducting electricity at a temperature of absolute zero. Many elements and compounds that are not normally classified as metals become metallic under high pressures. For example, the nonmetal iodine gradually becomes a metal at a pressure of between 40 and 170 thousand times atmospheric pressure. Equally, some materials regarded as metals c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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