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Phosphate (Pho) Regulon
The Phosphate (Pho) regulon is a regulatory mechanism used for the conservation and management of inorganic phosphate within the cell. It was first discovered in ''Escherichia coli'' as an operating system for the bacterial strain, and was later identified in other species. The Pho system is composed of various components including extracellular enzymes and transporters that are capable of phosphate assimilation in addition to extracting inorganic phosphate from organic sources. This is an essential process since phosphate plays an important role in cellular membranes, genetic expression, and metabolism within the cell. Under low nutrient availability, the Pho regulon helps the cell survive and thrive despite a depletion of phosphate within the environment. When this occurs, phosphate starvation-inducible (''psi'') genes activate other proteins that aid in the transport of inorganic phosphate. Function The Pho regulon is controlled by a two-component regulatory system composed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pho Regulon Summary
Phở or pho (, , ; ) is a Vietnamese soup dish consisting of broth, rice noodles (), herbs, and meat (usually beef (), sometimes chicken ()). Phở is a popular food in Vietnam where it is served in households, street stalls and restaurants countrywide. Nam Định people were the first to create Vietnamese traditional phở. Phở is considered Vietnam's national dish. Phở originated in the early 20th century in Northern Vietnam, and was popularized throughout the world by refugees after the Vietnam War. Because phở's origins are poorly documented, there is disagreement over the cultural influences that led to its development in Vietnam, as well as the etymology of the name. The Hanoi (northern) and Saigon (southern) styles of pho differ by noodle width, sweetness of broth, and choice of herbs and sauce. History Phở likely evolved from similar noodle dishes. For example, villagers in say they ate phở long before the French colonial period. The modern form emerged be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yeast
Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to constitute 1% of all described fungal species. Yeasts are unicellular organisms that evolved from multicellular ancestors, with some species having the ability to develop multicellular characteristics by forming strings of connected budding cells known as pseudohyphae or false hyphae. Yeast sizes vary greatly, depending on species and environment, typically measuring 3–4 µm in diameter, although some yeasts can grow to 40 µm in size. Most yeasts reproduce asexually by mitosis, and many do so by the asymmetric division process known as budding. With their single-celled growth habit, yeasts can be contrasted with molds, which grow hyphae. Fungal species that can take both forms (depending on temperature or other conditions) are ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anaerobic Organism
An anaerobic organism or anaerobe is any organism that does not require molecular oxygen for growth. It may react negatively or even die if free oxygen is present. In contrast, an aerobic organism (aerobe) is an organism that requires an oxygenated environment. Anaerobes may be unicellular (e.g. protozoans, bacteria) or multicellular. Most fungi are obligate aerobes, requiring oxygen to survive. However, some species, such as the Chytridiomycota that reside in the rumen of cattle, are obligate anaerobes; for these species, anaerobic respiration is used because oxygen will disrupt their metabolism or kill them. Deep waters of the ocean are a common anoxic environment. First observation In his letter of 14 June 1680 to The Royal Society, Antonie van Leeuwenhoek described an experiment he carried out by filling two identical glass tubes about halfway with crushed pepper powder, to which some clean rain water was added. Van Leeuwenhoek sealed one of the glass tubes using a flame an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biofilm
A biofilm comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular polymeric substances (EPSs). The cells within the biofilm produce the EPS components, which are typically a polymeric conglomeration of extracellular polysaccharides, proteins, lipids and DNA. Because they have three-dimensional structure and represent a community lifestyle for microorganisms, they have been metaphorically described as "cities for microbes". Biofilms may form on living or non-living surfaces and can be prevalent in natural, industrial, and hospital settings. They may constitute a microbiome or be a portion of it. The microbial cells growing in a biofilm are physiologically distinct from planktonic cells of the same organism, which, by contrast, are single cells that may float or swim in a liquid medium. Biofilms can form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vibrio Cholerae
''Vibrio cholerae'' is a species of Gram-negative, facultative anaerobe and comma-shaped bacteria. The bacteria naturally live in brackish or saltwater where they attach themselves easily to the chitin-containing shells of crabs, shrimps, and other shellfish. Some strains of ''V. cholerae'' are pathogenic to humans and cause a deadly disease cholera, which can be derived from the consumption of undercooked or raw marine life species. ''V. cholerae'' was first described by Félix-Archimède Pouchet in 1849 as some kind of protozoa. Filippo Pacini correctly identified it as a bacterium and from him, the scientific name is adopted. The bacterium as the cause of cholera was discovered by Robert Koch in 1884. Sambhu Nath De isolated the cholera toxin and demonstrated the toxin as the cause of cholera in 1959. The bacterium has a flagellum at one pole and several pili throughout its cell surface. It undergoes respiratory and fermentative metabolism. Two serogroups called O1 and O139 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyocyanin
Pyocyanin (PCN−) is one of the many toxic compounds produced and secreted by the Gram negative bacterium ''Pseudomonas aeruginosa''. Pyocyanin is a blue secondary metabolite, turning red below pH 4.9, with the ability to oxidise and reduce other molecules and therefore kill microbes competing against ''P. aeruginosa'' as well as mammalian cells of the lungs which ''P. aeruginosa'' has infected during cystic fibrosis. Since pyocyanin is a zwitterion at blood pH, it is easily able to cross the cell membrane. There are three different states in which pyocyanin can exist: oxidized (blue), monovalently reduced (colourless) or divalently reduced (red). Mitochondria play an important role in the cycling of pyocyanin between its redox states. Due to its redox-active properties, pyocyanin generates reactive oxygen species. Biosynthesis Pyocyanin biosynthesis begins with the synthesis of the phenazine-1-carboxylic acid (PCA) core. In this reaction the enzyme PhzE catalyzes the loss of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacillus Subtilis
''Bacillus subtilis'', known also as the hay bacillus or grass bacillus, is a Gram-positive, catalase-positive bacterium, found in soil and the gastrointestinal tract of ruminants, humans and marine sponges. As a member of the genus ''Bacillus'', ''B. subtilis'' is rod-shaped, and can form a tough, protective endospore, allowing it to tolerate extreme environmental conditions. ''B. subtilis'' has historically been classified as an obligate aerobe, though evidence exists that it is a facultative anaerobe. ''B. subtilis'' is considered the best studied Gram-positive bacterium and a model organism to study bacterial chromosome replication and cell differentiation. It is one of the bacterial champions in secreted enzyme production and used on an industrial scale by biotechnology companies. Description ''Bacillus subtilis'' is a Gram-positive bacterium, rod-shaped and catalase-positive. It was originally named ''Vibrio subtilis'' by Christian Gottfried Ehrenberg, and renamed ''B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudomonas Fluorescens
''Pseudomonas fluorescens'' is a common Gram-negative, rod-shaped bacterium. It belongs to the ''Pseudomonas'' genus; 16S rRNA analysis as well as phylogenomic analysis has placed ''P. fluorescens'' in the ''P. fluorescens'' group within the genus, Text was copied from this source, which is available under Creative Commons Attribution 4.0 International License to which it lends its name. General characteristics ''Pseudomonas fluorescens'' has multiple flagella. It has an extremely versatile metabolism, and can be found in the soil and in water. It is an obligate aerobe, but certain strains are capable of using nitrate instead of oxygen as a final electron acceptor during cellular respiration. Optimal temperatures for growth of ''P. fluorescens'' are 25–30° C. It tests positive for the oxidase test. It is also a nonsaccharolytic bacterial species. Heat-stable lipases and proteases are produced by ''P. fluorescens'' and other similar pseudomonads. These enzymes cause m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enterobacter Aerogenes
''Klebsiella aerogenes'', previously known as ''Enterobacter aerogenes,'' is a Gram-negative, oxidase negative, catalase positive, citrate positive, indole negative, rod-shaped bacterium. The bacterium is approximately 1-3 microns in length, and is capable of motility via peritrichous flagella. ''Klebsiella aerogenes'' is a nosocomial and pathogenic bacterium that causes opportunistic infections including most types of infections. The majority are sensitive to most antibiotics designed for this bacteria class, but this is complicated by their inducible resistance mechanisms, particularly lactamase, which means that they quickly become resistant to standard antibiotics during treatment, requiring a change in antibiotic to avoid worsening of the sepsis. Some of the infections caused by ''K. aerogenes'' result from specific antibiotic treatments, venous catheter insertions, and/or surgical procedures. ''K. aerogenes'' is generally found in the human gastrointestinal tract and does ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salmonella Enterica Subsp
''Salmonella'' is a genus of bacillus (shape), rod-shaped (bacillus) Gram-negative bacteria of the family Enterobacteriaceae. The two species of ''Salmonella'' are ''Salmonella enterica'' and ''Salmonella bongori''. ''S. enterica'' is the type species and is further divided into six subspecies that include over 2,600 serotypes. ''Salmonella'' was named after Daniel Elmer Salmon (1850–1914), an American veterinary surgeon. ''Salmonella'' species are non-Endospore, spore-forming, predominantly motility, motile enterobacteriaceae, enterobacteria with cell diameters between about 0.7 and 1.5 micrometre, μm, lengths from 2 to 5 μm, and peritrichous flagellum, flagella (all around the cell body, allowing them to move). They are chemotrophs, obtaining their energy from Redox, oxidation and reduction reactions, using organic sources. They are also facultative aerobic organism, facultative anaerobes, capable of generating Adenosine triphosphate, ATP with oxygen ("aerobically") wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudomonas Aeruginosa
''Pseudomonas aeruginosa'' is a common encapsulated, gram-negative, aerobic–facultatively anaerobic, rod-shaped bacterium that can cause disease in plants and animals, including humans. A species of considerable medical importance, ''P. aeruginosa'' is a multidrug resistant pathogen recognized for its ubiquity, its intrinsically advanced antibiotic resistance mechanisms, and its association with serious illnesses – hospital-acquired infections such as ventilator-associated pneumonia and various sepsis syndromes. The organism is considered opportunistic insofar as serious infection often occurs during existing diseases or conditions – most notably cystic fibrosis and traumatic burns. It generally affects the immunocompromised but can also infect the immunocompetent as in hot tub folliculitis. Treatment of ''P. aeruginosa'' infections can be difficult due to its natural resistance to antibiotics. When more advanced antibiotic drug regimens are needed adverse effects may re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photolyase
Photolyases () are DNA repair enzymes that repair damage caused by exposure to ultraviolet light. These enzymes require visible light (from the violet/blue end of the spectrum) both for their own activation and for the actual DNA repair. The DNA repair mechanism involving photolyases is called photoreactivation. They mainly convert pyrimidine dimers into a normal pair of pyrimidine bases. Function Photolyases bind complementary DNA strands and break certain types of pyrimidine dimers that arise when a pair of thymine or cytosine bases on the same strand of DNA become covalently linked. The bond length of this dimerization is shorter than the bond length of normal B-DNA structure which produces an incorrect template for replication and transcription. The more common covalent linkage involves the formation of a cyclobutane bridge. Photolyases have a high affinity for these lesions and reversibly bind and convert them back to the original bases. Evolution Photolyase is a ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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