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Nif Gene
The ''nif'' genes are genes encoding enzymes involved in the fixation of atmospheric nitrogen into a form of nitrogen available to living organisms. The primary enzyme encoded by the ''nif'' genes is the nitrogenase complex which is in charge of converting atmospheric nitrogen (N2) to other nitrogen forms such as ammonia which the organism can use for various purposes. Besides the nitrogenase enzyme, the ''nif'' genes also encode a number of regulatory proteins involved in nitrogen fixation. The ''nif'' genes are found in both free-living nitrogen-fixing bacteria and in symbiotic bacteria associated with various plants. The expression of the ''nif'' genes is induced as a response to low concentrations of fixed nitrogen and oxygen concentrations (the low oxygen concentrations are actively maintained in the root environment of host plants). The first Rhizobium genes for nitrogen fixation (nif) and for nodulation (nod) were cloned in the early 1980s by Gary Ruvkun and Sharon R. Lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and non-coding genes. During gene expression (the synthesis of Gene product, RNA or protein from a gene), DNA is first transcription (biology), copied into RNA. RNA can be non-coding RNA, directly functional or be the intermediate protein biosynthesis, template for the synthesis of a protein. The transmission of genes to an organism's offspring, is the basis of the inheritance of phenotypic traits from one generation to the next. These genes make up different DNA sequences, together called a genotype, that is specific to every given individual, within the gene pool of the population (biology), population of a given species. The genotype, along with environmental and developmental factors, ultimately determines the phenotype ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Root Nodule
Root nodules are found on the roots of plants, primarily legumes, that form a symbiosis with nitrogen-fixing bacteria. Under nitrogen-limiting conditions, capable plants form a symbiotic relationship with a host-specific strain of bacteria known as rhizobia. This process has evolved multiple times within the legumes, as well as in other species found within the Rosid clade. Legume crops include beans, peas, and soybeans. Within legume root nodules, nitrogen gas (N2) from the atmosphere is converted into ammonia (NH3), which is then assimilated into amino acids (the building blocks of proteins), nucleotides (the building blocks of DNA and RNA as well as the important energy molecule ATP), and other cellular constituents such as vitamins, flavones, and hormones. Their ability to fix gaseous nitrogen makes legumes an ideal agricultural organism as their requirement for nitrogen fertilizer is reduced. Indeed, high nitrogen content blocks nodule development as there is no benefit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Legume
Legumes are plants in the pea family Fabaceae (or Leguminosae), or the fruit or seeds of such plants. When used as a dry grain for human consumption, the seeds are also called pulses. Legumes are grown agriculturally, primarily for human consumption, but also as livestock forage and silage, and as soil-enhancing green manure. Legumes produce a botanically unique type of fruit – a simple fruit, simple Dry fruits, dry fruit that develops from a simple carpel and usually Dehiscence (botany) , dehisces (opens along a seam) on two sides. Most legumes have Symbiosis , symbiotic nitrogen fixation , nitrogen-fixing bacteria, Rhizobia, in structures called root nodules. Some of the fixed nitrogen becomes available to later crops, so legumes play a key role in crop rotation. Terminology The term ''pulse'', as used by the United Nations' Food and Agriculture Organization (FAO), is reserved for legume crops harvested solely for the dry seed. This excludes green beans and Pea , green ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhizobium
''Rhizobium'' is a genus of Gram-negative soil bacteria that fix nitrogen. ''Rhizobium'' species form an endosymbiotic nitrogen-fixing association with roots of (primarily) legumes and other flowering plants. The bacteria colonize plant cells to form root nodules, where they convert atmospheric nitrogen into ammonia using the enzyme nitrogenase. The ammonia is shared with the host plant in the form of organic nitrogenous compounds such as glutamine or ureides. The plant, in turn, provides the bacteria with organic compounds made by photosynthesis. This mutually beneficial relationship is true of all of the rhizobia, of which the genus ''Rhizobium'' is a typical example. ''Rhizobium'' is also capable of solubilizing phosphate. History Martinus Beijerinck was the first to isolate and cultivate a microorganism from the nodules of legumes in 1888. He named it ''Bacillus radicicola'', which is now placed in '' Bergey's Manual of Determinative Bacteriology'' under the gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhodobacter
''Rhodobacter'' is a genus of bacteria in the family Rhodobacteraceae The Rhodobacteraceae are a family of Pseudomonadota in the order Rhodobacterales within the alpha subgroup.See the NCBIbr>webpage on Rhodobacteraceae Data extracted from the Like all Pseudomonadota, they are gram-negative. It contains chem .... The most famous species of ''Rhodobacter'' are '' Rhodobacter sphaeroides'' and '' Rhodobacter capsulatus'', which are used as model organisms to study bacterial photosynthesis. References Rhodobacteraceae Bacteria genera {{Rhodobacterales-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arginine
Arginine is the amino acid with the formula (H2N)(HN)CN(H)(CH2)3CH(NH2)CO2H. The molecule features a guanidinium, guanidino group appended to a standard amino acid framework. At physiological pH, the carboxylic acid is deprotonated (−CO2−) and both the amino and guanidino groups are protonated, resulting in a cation. Only the -arginine (symbol Arg or R) enantiomer is found naturally. Arg residues are common components of proteins. It is Genetic code, encoded by the DNA codon table, codons CGU, CGC, CGA, CGG, AGA, and AGG. The guanidine group in arginine is the Precursor (chemistry), precursor for the biosynthesis of nitric oxide. Like all amino acids, it is a white, water-soluble solid. The one-letter symbol R was assigned to arginine for its phonetic similarity. History Arginine was first isolated in 1886 from Lupinus luteus, yellow lupin seedlings by the German chemist Ernst Schulze (chemist), Ernst Schulze and his assistant Ernst Steiger. He named it from the Greek ''árg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ADP-ribosylation
ADP-ribosylation is the addition of one or more ADP-ribose moieties to a protein. It is a reversible post-translational modification that is involved in many cellular processes, including cell signaling, DNA repair, gene regulation and apoptosis. Improper ADP-ribosylation has been implicated in some forms of cancer. It is also the basis for the toxicity of bacterial compounds such as cholera toxin, diphtheria toxin, and others. History The first suggestion of ADP-ribosylation surfaced during the early 1960s. At this time, Pierre Chambon and coworkers observed the incorporation of ATP into hen liver nuclei extract. After extensive studies on the acid insoluble fraction, several different research laboratories were able to identify ADP-ribose, derived from NAD+, as the incorporated group. Several years later, the enzymes responsible for this incorporation were identified and given the name poly(ADP-ribose)polymerase. Originally, this group was thought to be a linear sequence of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhodospirillum Rubrum
''Rhodospirillum rubrum'' (''R. rubrum'') is a Gram-negative, pink-coloured bacterium, with a size of 0.8-1 μm. It is a facultative anaerobe with a large set of possible metabolisms depending on the conditions of its environment. It's capable of using oxygen for aerobic respiration under aerobic conditions, or an alternative terminal electron acceptor for anaerobic respiration under anaerobic conditions. Alternative terminal electron acceptors for ''R. rubrum'' include dimethyl sulfoxide or trimethylamine oxide. Under aerobic growth photosynthesis is genetically suppressed and ''R. rubrum'' is then colorless. After the exhaustion of oxygen, ''R. rubrum'' immediately starts the production of photosynthesis apparatus including membrane proteins, bacteriochlorophylls and carotenoids, i.e. the bacterium becomes photosynthesis active. The repression mechanism for the photosynthesis is poorly understood. The photosynthesis of ''R. rubrum'' differs from that of plants as it possesses ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molybdenum
Molybdenum is a chemical element; it has Symbol (chemistry), symbol Mo (from Neo-Latin ''molybdaenum'') and atomic number 42. The name derived from Ancient Greek ', meaning lead, since its ores were confused with lead ores. Molybdenum minerals have been known throughout history, but the element was discovered (in the sense of differentiating it as a new entity from the mineral salts of other metals) in 1778 by Carl Wilhelm Scheele. The metal was first isolated in 1781 by Peter Jacob Hjelm. Molybdenum does not occur naturally as a Native metal, free metal on Earth; in its minerals, it is found only in oxidation state, oxidized states. The free element, a silvery metal with a grey cast, has the List of elements by melting point, sixth-highest melting point of any element. It readily forms hard, stable carbides in alloys, and for this reason most of the world production of the element (about 80%) is used in steel alloys, including high-strength alloys and superalloys. Most molybdenum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron
Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's outer and inner core. It is the fourth most abundant element in the Earth's crust, being mainly deposited by meteorites in its metallic state. Extracting usable metal from iron ores requires kilns or furnaces capable of reaching , about 500 °C (900 °F) higher than that required to smelt copper. Humans started to master that process in Eurasia during the 2nd millennium BC and the use of iron tools and weapons began to displace copper alloys – in some regions, only around 1200 BC. That event is considered the transition from the Bronze Age to the Iron Age. In the modern world, iron alloys, such as steel, stainless steel, cast iron and special steels, are by far the most common industrial metals, due to their mechan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Klebsiella Pneumoniae
''Klebsiella pneumoniae'' is a Gram-negative, non-motile, encapsulated, lactose- fermenting, facultative anaerobic, rod-shaped bacterium. It appears as a mucoid lactose fermenter on MacConkey agar. Although found in the normal flora of the mouth, skin, and intestines, it can cause destructive changes to human and animal lungs if aspirated, specifically to the alveoli, resulting in bloody, brownish or yellow colored jelly-like sputum. In the clinical setting, it is the most significant member of the genus ''Klebsiella'' of the Enterobacteriaceae. ''K. oxytoca'' and ''K. rhinoscleromatis'' have also been demonstrated in human clinical specimens. In recent years, ''Klebsiella'' species have become important pathogens in nosocomial infections. It naturally occurs in the soil, and about 30% of strains can fix nitrogen in anaerobic conditions. As a free-living diazotroph, its nitrogen-fixation system has been much-studied, and is of agricultural interest, as ''K. pneumoniae'' has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genomic Island
A genomic island (GI) is part of a genome that has evidence of horizontal origins. The term is usually used in microbiology, especially with regard to bacteria. A GI can code for many functions, can be involved in symbiosis or pathogenesis, and may help an organism's adaptation. Many sub-classes of GIs exist that are based on the function that they confer. For example, a GI associated with pathogenesis is often called a pathogenicity island (PAIs), while GIs that contain many antibiotic resistant genes are referred to as antibiotic resistance islands. The same GI can occur in distantly related species as a result of various types of horizontal gene transfer (transformation, conjugation, transduction). This can be determined by base composition analysis, as well as phylogeny estimations. Computational prediction Various genomic island predictions programs have been developed. These tools can be broadly grouped into sequence based methods and comparative genomics/phylogeny bas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
