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Pseudomonas Stutzeri
''Pseudomonas stutzeri'' is a Gram-negative soil bacterium that is motile, has a single polar flagellum, and is classified as bacillus, or rod-shaped. While this bacterium was first isolated from human spinal fluid, it has since been found in many different environments due to its various characteristics and metabolic capabilities. ''P. stutzeri'' is an opportunistic pathogen in clinical settings, although infections are rare. Based on 16S rRNA analysis, this bacterium has been placed in the ''P. stutzeri'' group, to which it lends its name. Taxonomy ''P. stutzeri'' is most easily differentiated from the other ''Pseudomonas spp.'' in that it does not produce fluorescent pigments''.'' ''P. mendocina, P. alcaligenes, P. pseudoalcaligenes'', and ''P. balearica'' are classified within the same branch of pseudomonads as ''P. stutzeri'' based on 16S rRNA sequences and other phylogenetic markers. Of this group, ''P. stutzeri'' is most closely related to ''P. balearica'' and they can b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walter Migula
Emil Friedrich August Walter (or Walther) Migula (born 1863 in Zyrowa, Prussia (present-day Poland); died 1938 in Eisenach, Germany) was a German botanist. In 1890, he was habilitated for botany at Karlsruhe Institute of Technology, where he spent several years as a professor. At Karlsruhe, he also worked in the bacteriology department of the Food Research Institute. He was Professor of Botany at the research academy at Eisenach. He published many articles on the subjects of cryptogamic botany, bacteriology, and plant physiology. Between 1892 and 1933 Migula issued exsiccata series, among them ''Kryptogamae Germaniae, Austriae et Helvetiae exsiccatae''.Triebel, D. & Scholz, P. 2001–2024 ''IndExs – Index of Exsiccatae''. – Botanische Staatssammlung München: http://indexs.botanischestaatssammlung.de. – München, Germany. He is remembered for describing the bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anaerobic Organism
An anaerobic organism or anaerobe is any organism that does not require oxygen, 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. The sea floor is possibly one of the largest accumulation of anaerobic organisms on Earth, where microbes are primarily concentrated around Hydrothermal_vent, hydrothermal vents. These microbes produce energy in absence of sunlight or oxygen through a process called chemosynthesis, whereby inorganic compounds such as hydrogen gas, hydrogen sulfide or ferrous ions are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen Fixation
Nitrogen fixation is a chemical process by which molecular dinitrogen () is converted into ammonia (). It occurs both biologically and abiological nitrogen fixation, abiologically in chemical industry, chemical industries. Biological nitrogen fixation or ''diazotrophy'' is catalyzed by enzymes called nitrogenases. These enzyme complexes are encoded by the Nif gene, ''Nif'' genes (or ''Nif'' homologs) and contain iron, often with a second metal (usually molybdenum, but sometimes vanadium). Some nitrogen-fixing bacteria have symbiotic relationships with plants, especially legumes, mosses and aquatic ferns such as ''Azolla''. Looser non-symbiotic relationships between diazotrophs and plants are often referred to as associative, as seen in nitrogen fixation on rice roots. Nitrogen fixation occurs between some termites and fungus, fungi. It occurs naturally in the air by means of NOx, NOx production by lightning. Fixed nitrogen is essential to life on Earth. Organic compounds such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pilus
A pilus (Latin for 'hair'; : pili) is a hair-like cell-surface appendage found on many bacteria and archaea. The terms ''pilus'' and '' fimbria'' (Latin for 'fringe'; plural: ''fimbriae'') can be used interchangeably, although some researchers reserve the term ''pilus'' for the appendage required for bacterial conjugation. All conjugative pili are primarily composed of pilin – fibrous proteins, which are oligomeric. Dozens of these structures can exist on the bacterial and archaeal surface. Some bacteria, viruses or bacteriophages attach to receptors on pili at the start of their reproductive cycle. Pili are antigenic. They are also fragile and constantly replaced, sometimes with pili of different composition, resulting in altered antigenicity. Specific host responses to old pili structures are not effective on the new structure. Recombination between genes of some (but not all) pili code for variable (V) and constant (C) regions of the pili (similar to immunoglobulin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Chloride
Sodium chloride , commonly known as Salt#Edible salt, edible salt, is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions. It is transparent or translucent, brittle, hygroscopic, and occurs as the mineral halite. In its edible form, it is commonly used as a condiment and curing (food preservation), food preservative. Large quantities of sodium chloride are used in many industrial processes, and it is a major source of sodium and chlorine compounds used as feedstocks for further Chemical synthesis, chemical syntheses. Another major application of sodium chloride is deicing of roadways in sub-freezing weather. Uses In addition to the many familiar domestic uses of salt, more dominant applications of the approximately 250 million tonnes per year production (2008 data) include chemicals and de-icing.Westphal, Gisbert ''et al.'' (2002) "Sodium Chloride" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim . Chem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterial Growth
250px, Growth is shown as ''L'' = log(numbers) where numbers is the number of colony forming units per ml, versus ''T'' (time.) Bacterial growth is proliferation of bacterium into two daughter cells, in a process called binary fission. Providing no mutation event occurs, the resulting daughter cells are genetically identical to the original cell. Hence, bacterial growth occurs. Both daughter cells from the division do not necessarily survive. However, if the surviving number exceeds unity on average, the bacterial population undergoes exponential growth. The measurement of an exponential bacterial growth curve in batch culture was traditionally a part of the training of all microbiologists; the basic means requires bacterial enumeration (cell counting) by direct and individual (microscopic, flow cytometry), direct and bulk (biomass), indirect and individual (colony counting), or indirect and bulk (most probable number, turbidity, nutrient uptake) methods. Models reconcile theor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Growth Medium
A growth medium or culture medium is a solid, liquid, or semi-solid designed to support the growth of a population of microorganisms or cells via the process of cell proliferation or small plants like the moss ''Physcomitrella patens''. Different types of media are used for growing different types of cells. The two major types of growth media are those used for cell culture, which use specific cell types derived from plants or animals, and those used for microbiological culture, which are used for growing microorganisms such as bacteria or fungi. The most common growth media for microorganisms are nutrient broths and agar plates; specialized media are sometimes required for microorganism and cell culture growth. Some organisms, termed fastidious organisms, require specialized environments due to complex nutritional requirements. Viruses, for example, are obligate intracellular parasites and require a growth medium containing living cells. Types The most common growth media ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asparagine
Asparagine (symbol Asn or N) is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated −NH form under biological conditions), an α-carboxylic acid group (which is in the deprotonated −COO− form under biological conditions), and a side chain carboxamide, classifying it as a polar (at physiological pH), aliphatic amino acid. It is non-essential in humans, meaning the body can synthesize it. It is encoded by the codons AAU and AAC. The one-letter symbol N for asparagine was assigned arbitrarily, with the proposed mnemonic asparagi''N''e; History Asparagine was first isolated in 1806 in a crystalline form by French chemists Louis Nicolas Vauquelin and Pierre Jean Robiquet (then a young assistant). It was isolated from asparagus juice, in which it is abundant, hence the chosen name. It was the first amino acid to be isolated. Three years later, in 1809, Pierre Jean Robiquet identified a substance from l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doubling Time
The doubling time is the time it takes for a population to double in size/value. It is applied to population growth, inflation, resource extraction, consumption of goods, compound interest, the volume of malignant tumours, and many other things that tend to grow over time. When the relative growth rate (not the absolute growth rate) is constant, the quantity undergoes exponential growth and has a constant doubling time or period, which can be calculated directly from the growth rate. This time can be calculated by dividing the natural logarithm of 2 by the exponent of growth, or approximated by dividing 70 by the percentage growth rate (more roughly but roundly, dividing 72; see the rule of 72 for details and derivations of this formula). The doubling time is a characteristic unit (a natural unit of scale) for the exponential growth equation, and its converse for exponential decay is the half-life. As an example, Canada's net population growth was 2.7 percent in the year 202 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lysogeny Broth
Lysogeny broth (LB) is a Nutrient, nutritionally rich Growth medium, medium primarily used for the Bacterial growth, growth of bacteria. Its creator, Giuseppe Bertani, intended LB to stand for lysogeny broth, but LB has also come to colloquially mean Luria broth, Lennox broth, life broth or Salvador Luria, Luria–Bertani medium. The formula of the LB medium was published in 1951 in the first paper of Bertani on lysogeny. In this article he described the modified single-burst experiment and the isolation of the phages Enterobacteria phage P1, P1, Enterobacteria phage P2, P2, and Enterobacteria phage P3, P3. He had developed the LB medium to optimize ''Shigella'' growth and Virus Quantification#Plaque assay, plaque formation. LB medium formulations have been an industry standard for the cultivation of ''Escherichia coli (molecular biology), Escherichia coli'' as far back as the 1950s. These media have been widely used in molecular microbiology applications for the preparation of pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesophile
A mesophile is an organism that grows best in moderate temperature, neither too hot nor too cold, with an optimum growth range from . The optimum growth temperature for these organisms is 37 °C (about 99 °F). The term is mainly applied to microorganisms. Organisms that prefer extreme environments are known as extremophiles. Mesophiles have diverse classifications, belonging to two domains: Bacteria, Archaea, and to kingdom Fungi of domain Eucarya. Mesophiles belonging to the domain Bacteria can either be gram-positive or gram-negative. Oxygen requirements for mesophiles can be aerobic or anaerobic. There are three basic shapes of mesophiles: coccus, bacillus, and spiral. Habitat The habitats of mesophiles can include cheese and yogurt. They are often included during fermentation of beer and wine making. Since normal human body temperature is 37 °C, the majority of human pathogens are mesophiles, as are most of the organisms comprising the human microbiome. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidase Test
The oxidase test is used to determine whether an organism possesses the cytochrome c oxidase enzyme. The test is used as an aid for the differentiation of ''Neisseria'', ''Moraxella'', ''Campylobacter'' and ''Pasteurella'' species (oxidase positive). It is also used to differentiate pseudomonads from related species.MacFaddin JF, editor. Biochemical Tests for Identification of Medical Bacteria. 3rd ed. Philadelphia:Lippincott Williams and Wilkins; 2000. p. 363-7 Classification Strains may be either oxidase-positive (OX+) or oxidase-negative (OX-). OX+ OX+ normally means the bacterium contains cytochrome c oxidase (also known as Complex IV) and can therefore use oxygen for energy production by converting O2 to H2O2 or H2O with an electron transfer chain. The Pseudomonadaceae are typically OX+. The Gram-negative diplococci Neisseria and Moraxella are oxidase-positive. Many Gram-negative, spiral curved rods are also oxidase-positive, which includes ''Helicobacter pylori'', ''Vibrio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
