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Microaerobic
A microaerophile is a microorganism that requires environments containing lower levels of dioxygen than that are present in the atmosphere (i.e. < 21% O2; typically 2–10% O2) for optimal growth. A more restrictive interpretation requires the microorganism to be obligate in this requirement. Many microaerophiles are also capnophiles, requiring an elevated concentration of (e.g. 10% CO2 in the case of '' Campylobacter'' ). The original definiti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anaerobic
Anaerobic means "living, active, occurring, or existing in the absence of free oxygen", as opposed to aerobic which means "living, active, or occurring only in the presence of oxygen." Anaerobic may also refer to: * Anaerobic adhesive, a bonding agent that does not cure in the presence of air *Anaerobic respiration, respiration in the absence of oxygen, using some other molecule as the final electron acceptor **Anaerobic organism, any organism whose redox metabolism does not depend on free oxygen **Anammox, anaerobic ammonium oxidation, a globally important microbial process of the nitrogen cycle **Anaerobic filter, an anaerobic digester with a tank containing a filter medium where anaerobic microbes can establish themselves **Anaerobic digestion, the use of anaerobic bacteria to break down waste, with biogas as a byproduct ***Anaerobic clarigester, an anaerobic digester that treats dilute biodegradable feedstocks and allows different retention times for solids and liquids ***Anaer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastritis
Gastritis is inflammation of the lining of the stomach. It may occur as a short episode or may be of a long duration. There may be no symptoms but, when symptoms are present, the most common is upper abdominal pain (see dyspepsia). Other possible symptoms include nausea and vomiting, bloating, loss of appetite and heartburn. Complications may include stomach bleeding, stomach ulcers, and stomach tumors. When due to autoimmune problems, low red blood cells due to not enough vitamin B12 may occur, a condition known as pernicious anemia. Common causes include infection with '' Helicobacter pylori'' and use of nonsteroidal anti-inflammatory drugs ( NSAIDs). Less common causes include alcohol, smoking, cocaine, severe illness, autoimmune problems, radiation therapy and Crohn's disease. Endoscopy, a type of X-ray known as an upper gastrointestinal series, blood tests, and stool tests may help with diagnosis. The symptoms of gastritis may be a presentation of a myocardial infarcti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obligate Anaerobe
Obligate anaerobes are microorganisms killed by normal atmospheric concentrations of oxygen (20.95% O2). Oxygen tolerance varies between species, with some species capable of surviving in up to 8% oxygen, while others lose viability in environments with an oxygen concentration greater than 0.5%. Oxygen sensitivity The oxygen sensitivity of obligate anaerobes has been attributed to a combination of factors including oxidative stress and enzyme production. Oxygen can also damage obligate anaerobes in ways not involving oxidative stress. Because molecular oxygen contains two unpaired electrons in the highest occupied molecular orbital, it is readily reduced to superoxide () and hydrogen peroxide () within cells. A reaction between these two products results in the formation of a free hydroxyl radical (OH.). Superoxide, hydrogen peroxide, and hydroxyl radicals are a class of compounds known as reactive oxygen species (ROS), highly reactant products that are damaging to microbes, in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obligate Aerobe
An obligate aerobe is an organism that requires oxygen to grow. Through cellular respiration, these organisms use oxygen to metabolise substances, like sugars or fats, to obtain energy. In this type of respiration, oxygen serves as the terminal electron acceptor for the electron transport chain. Aerobic respiration has the advantage of yielding more energy ( adenosine triphosphate or ATP) than fermentation or anaerobic respiration, but obligate aerobes are subject to high levels of oxidative stress."Obligate aerobe - definition from Biology-Online.org." ''Biology Online.'' Biology-Online, n.d. Web. 12 Dec 2009. Examples Among organisms, almost all animals, most fungi, and several bacteria are obligate aerobes. Examples of obligately aerobic bacteria include ''Mycobacterium tuberculosis'' (acid-fast), ''Pseudomonas aeruginosa'' (Gram-negative), ''Bacillus'' (Gram-positive), and ''Nocardia asteroides'' (Gram-positive). With the exception of the yeasts, most fungi are obligate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fermentation
Fermentation is a metabolic process that produces chemical changes in organic substrates through the action of enzymes. In biochemistry, it is narrowly defined as the extraction of energy from carbohydrates in the absence of oxygen. In food production, it may more broadly refer to any process in which the activity of microorganisms brings about a desirable change to a foodstuff or beverage. The science of fermentation is known as zymology. In microorganisms, fermentation is the primary means of producing adenosine triphosphate (ATP) by the degradation of organic nutrients anaerobically. Humans have used fermentation to produce foodstuffs and beverages since the Neolithic age. For example, fermentation is used for preservation in a process that produces lactic acid found in such sour foods as pickled cucumbers, kombucha, kimchi, and yogurt, as well as for producing alcoholic beverages such as wine and beer. Fermentation also occurs within the gastrointestinal tracts of all a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Facultative Anaerobic Organism
A facultative anaerobic organism is an organism that makes Adenosine triphosphate, ATP by aerobic respiration if oxygen is present, but is capable of switching to Fermentation (biochemistry), fermentation if oxygen is absent. Some examples of facultatively anaerobic bacteria are ''Staphylococcus'' Species, spp., ''Escherichia coli'', ''Salmonella'', ''Listeria'' spp., ''Shewanella oneidensis'' and ''Yersinia pestis''. Certain eukaryotes are also facultative anaerobes, including fungi such as ''Saccharomyces cerevisiae'' and many aquatic invertebrates such as Nereid (worm), nereid polychaetes. See also * Aerobic respiration * Anaerobic respiration * Fermentation * Obligate aerobe * Obligate anaerobe * Microaerophile References External links Facultative Anaerobic Bacteria {{Bacteria Anaerobic respiration Cellular respiration ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anaerobic Respiration
Anaerobic respiration is respiration using electron acceptors other than molecular oxygen (O2). Although oxygen is not the final electron acceptor, the process still uses a respiratory electron transport chain. In aerobic organisms undergoing respiration, electrons are shuttled to an electron transport chain, and the final electron acceptor is oxygen. Molecular oxygen is an excellent electron acceptor. Anaerobes instead use less-oxidizing substances such as nitrate (), fumarate (), sulfate (), or elemental sulfur (S). These terminal electron acceptors have smaller reduction potentials than O2. Less energy per oxidized molecule is released. Therefore, anaerobic respiration is less efficient than aerobic. As compared with fermentation Anaerobic cellular respiration and fermentation generate ATP in very different ways, and the terms should not be treated as synonyms. Cellular respiration (both aerobic and anaerobic) uses highly reduced chemical compounds such as NADH and FADH2 ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerobic Respiration
Cellular respiration is the process by which biological fuels are oxidised in the presence of an inorganic electron acceptor such as oxygen to produce large amounts of energy, to drive the bulk production of ATP. Cellular respiration may be described as a set of metabolic reactions and processes that take place in the cells of organisms to convert chemical energy from nutrients into adenosine triphosphate (ATP), and then release waste products. The reactions involved in respiration are catabolic reactions, which break large molecules into smaller ones, releasing energy. Respiration is one of the key ways a cell releases chemical energy to fuel cellular activity. The overall reaction occurs in a series of biochemical steps, some of which are redox reactions. Although cellular respiration is technically a combustion reaction, it is an unusual one because of the slow, controlled release of energy from the series of reactions. Nutrients that are commonly used by animal and pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetotactic Bacteria
Magnetotactic bacteria (or MTB) are a polyphyletic group of bacteria that orient themselves along the magnetic field lines of Earth's magnetic field. Discovered in 1963 by Salvatore Bellini and rediscovered in 1975 by Richard Blakemore, this alignment is believed to aid these organisms in reaching regions of optimal oxygen concentration. To perform this task, these bacteria have organelles called magnetosomes that contain magnetic crystals. The biological phenomenon of microorganisms tending to move in response to the environment's magnetic characteristics is known as magnetotaxis. However, this term is misleading in that every other application of the term taxis involves a stimulus-response mechanism. In contrast to the magnetoreception of animals, the bacteria contain fixed magnets that force the bacteria into alignment—even dead cells are dragged into alignment, just like a compass needle. Introduction The first description of magnetotactic bacteria was in 1963 by Salvat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetospirillum Gryphiswaldense
''Magnetospirillum'' is a Gram-negative, microaerophilic genus of magnetotactic bacterium, first isolated from pond water by the microbiologist R. P. Blakemore in 1975. They have a spiral (helical) shape and are propelled by a polar flagellum at each end of their cells. Four species have been described: ''M. magnetotacticum'' strain MS-1 (originally classified as ''Aquaspirillum magnetotacticum''; ''M. magneticum'' strain AMB-1; ''M. gryphiswaldense'' and ''M. bellicus''. Habitat The typical habitat of ''Magnetospirillum'' species consists of shallow fresh water and sediments, characterized by low concentrations of oxygen for growth (microaerophilic) where they live in the upper portion of the sediment (oxic/anoxic interface) and prefer an oxygen gradient of around 1–3%. Magnetotaxis Probably the most peculiar characteristic of ''Magnetospirillum'' species is their capacity to orient themselves according to Earth's magnetic field, magnetotaxis. This is achieved through th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactobacillaceae
The ''Lactobacillaceae'' are a family of lactic acid bacteria. It is the only family in the lactic acid bacteria which includes homofermentative and heterofermentative organisms; in the ''Lactobacillaceae,'' the pathway used for hexose fermentation is a genus-specific trait. ''Lactobacillaceae'' include the homofermentative lactobacilli ''Lactobacillus'', ''Holzapfelia'', ''Amylolactobacillus'', ''Bombilactobacillus'', ''Companilactobacillus'', ''Lapidilactobacillus'', ''Agrilactobacillus'', ''Schleiferilactobacillus'', ''Loigolactobacillus'', ''Lacticaseibacillus'', ''Latilactobacillus'', ''Dellaglioa'', ''Liquorilactobacillus'', ''Ligilactobacillus'', and ''Lactiplantibacillus''; the heterofermentative lactobacilli ''Furfurilactobacillus'', ''Paucilactobacillus'', ''Limosilactobacillus'', ''Fructilactobacillus'', ''Acetilactobacillus'', ''Apilactobacillus'', ''Levilactobacillus'', ''Secundilactobacillus'', and ''Lentilactobacillus,'' which were previously classified in the genus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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