Diazotrophs are bacteria and archaea that Nitrogen fixation fix atmospheric nitrogen gas into a more usable form such as ammonia . ref name Postgate98 cite book author Postgate, J year 1998 title Nitrogen Fixation, 3rd Edition publisher Cambridge University Press, Cambridge UK ref A diazotroph is an organism that is able to grow without external sources of fixed nitrogen. Examples of organisms that do this are rhizobia and Frankia in symbiosis and Azospirillum . All diazotrophs contain iron molybdenum or vanadium nitrogenase systems. Two of the most studied systems are those of Klebsiella pneumoniae and Azotobacter vinelandii . These systems are used because of their genetic tractability and their fast growth. ref name DK94 cite journal author Dixon R and Kahn D year 2004 title Genetic regulation of biological nitrogen fixation journal Nat Rev Microbiol volume 2 issue 8 pages 621 31 doi 10.1038 nrmicro954 pmid 15263897 ref Types of diazotrophs Diazotrophs are scattered across bacterial taxonomic groups mostly in the Bacteria but also a couple of Archaea . Even within a species that can fix nitrogen there may be strains that do not fix nitrogen. ref name Postgate98 Fixation is shut off when other sources of nitrogen are available, and, for many species, when oxygen is at high partial pressure. Bacteria have different ways of dealing with the debilitating effects of oxygen on nitrogenases, listed below. Free living diazotrophs Anaerobes these are obligate anaerobes that cannot tolerate oxygen even if they are not fixing nitrogen. They live in habitats low in oxygen, such as soils and decaying vegetable matter. Clostridium is an example. Sulphate reducing bacteria are important in ocean sediments e.g. Desulfovibrio , and some Archean methanogens fix nitrogen in muds and animal intestines. ref name Postgate98 Facultative anaerobes these species can grow either with or without oxygen, but they only fix nitrogen anaerobically. Often, they respire oxygen as rapidly as it i ... more details
multiple issues context February 2012 orphan February 2012 overly detailed February 2012 technical February 2012 expert subject Genetics date February 2012 imagemap Image Genomic region.png thumb right 350px Genomic regions of the identified S. meliloti sRNA genes. The schematics drawn to scale summarize the bioinformatic predictions and the results of the experimental mapping. The smr genes are represented by red arrows and the flanking ORFs by blue arrows. Numbers indicate co ordinates in the S. meliloti 1021 genome database. Experimentally determined 5 and 3 ends of the Smr transcripts are indicated with numbers. 3 ends of the differentially expressed sRNAs were assigned to the last U in the consecutive stretch after extended stem loops of Rho independent terminators, which are denoted by green dots above the horizontal lines. The grey arrowhead indicates the processing site for Smr7C. rect 0 0 650 80 r7 RNA Smr7C rect 0 120 650 200 r9 RNA Smr9C rect 0 240 650 320 r14 RNA Smr14C2 rect 0 360 650 440 r15 RNA Smr15C1 & Smr15C2 rect 0 480 650 560 http rfam.sanger.ac.uk family 6S Smr22C rect 0 600 650 680 r35 RNA Smr35B rect 0 720 650 800 r45 RNA Smr45C imagemap Genome Post genomic research has rendered bacterial small non coding RNAs sRNAs as major players in post transcriptional regulation of gene expression in response to environmental stimuli. ref name Maj05 cite journal author Majdalani N, Vanderpool CK, Gottesman S title Bacterial small RNA regulators journal Crit Rev Biochem Mol Biol volume 40 pages 93 113 year 2005 pmid 15814430 doi 10.1080 10409230590918702 ref The subdivision of the Proteobacteria includes Gram negative microorganisms with diverse life styles frequently involving long term interactions with higher eukaryotes . ref name Bat04 cite journal author Batut J, Andersson SGE, O Callaghan D title The evolution of chronic infection strategies in the proteobacteria journal Nat Rev volume 2 pages 933 945 year 2004 pmid 15550939 doi 10.1038 nrm ... more details
Unreferenced type bacteria auto yes date December 2009 Taxobox color lightgrey name Oxalobacteraceae regnum Bacteria phylum Proteobacteria classis Beta Proteobacteria ordo Burkholderiales familia Oxalobacteraceae subdivision ranks Genera subdivision Collimonas br Duganella br Herbaspirillum br Herminiimonas br Janthinospirillum br Massilia bacterium Massilia br Naxibacter br Oxalobacter br Oxalicibacterium br Telluria The Oxalobacteraceae are a family of bacteria , included in the order Burkholderiales . Like all Proteobacteria , Oxalobacteraceae are gram negative . The family includes strict Anaerobic organism aerobes , strict Aerobic organism anaerobes , and also Diazotroph nitrogen xing diazotrophic members. The cells are curved, vibroid or straight rod shaped. References Garrity, George M. Brenner, Don J. Krieg, Noel R. Staley, James T. eds. 2005 . Bergey s Manual of Systematic Bacteriology, Volume Two The Proteobacteria, Part C The Alpha , Beta , Delta , and Epsilonproteobacteria. New York, New York Springer. pp. 354 361. ISBN 978 0 387 24145 6. Category Burkholderiales Proteobacteria stub de Oxalobacteraceae es Oxalobacteraceae fr Oxalobacteraceae it Oxalobacteraceae ... more details
italic title Expert subject Microbiology date November 2008 Taxobox color lightgrey name Azotobacter regnum Bacterium Bacteria phylum Proteobacteria classis Gamma Proteobacteria ordo Pseudomonadales familia Pseudomonadaceae genus Azotobacter species A. vinelandii binomial Azotobacter vinelandii binomial authority Jacob Goodale Lipman Lipman ref cite book title Review of American Chemical Research volume 10 year 1904 editor William A. Noyes page http books.google.com books?id LAoSAAAAIAAJ&pg PA75 v onepage&q&f false 75 ref Azotobacter vinelandii is diazotroph that can fix nitrogen while grown aerobic organism aerobically . It is a genomics genetically tractable system that is used to study nitrogen fixation . These bacteria are easily cultured and grown. It is a free living N sub 2 sub fixer which is known to produce many phytohormone s and vitamin s in the soil. The nitrogenase enzyme holoenzyme of Azotobacter vinelandii has been characterised via x ray crystallography in both Adenosine diphosphate ADP tetrafluoroaluminate bound ref Schindelin, H., Kisker, C., Schlessman, J.L., Howard, J.B., Rees, D.C. 1997 Structure of ADP x AIF4 stabilized nitrogenase complex and its implications for signal transduction. Nature 387 370 376 ref and Mg Adenosine triphosphate ATP bound ref Chiu, H., Peters, J.W., Lanzilotta, W.N., Ryle, M.J., Seefeldt, L.C., Howard, J.B., Rees, D.C. 2001 MgATP Bound and nucleotide free structures of a nitrogenase protein complex between the Leu 127 Delta Fe protein and the MoFe protein. Biochemistry 40 641 650 ref states. The enzyme possesses molybdenum iron sulfido cluster Cofactor biochemistry cofactors FeMoCo as active site s, each bearing 2 pseudo cubic iron sulfido structures. References reflist External links http www.azotobacter.org Azotobacter vinelandii Genome Project http www.micron.ac.uk organisms Avi.html Current research on Azotobacter vinelandii at the Norwich Research Park Category Pseudomonadales Proteobacteria stub es Azotobacter vin ... more details
italic title Refimprove type bacteria date December 2009 Taxobox color lightgrey name Azomonas image azomonas100x.jpg image width 250px image caption Azmonas under 100x oil immersion. regnum Bacterium Bacteria phylum Proteobacteria classis Gammaproteobacteria ordo Pseudomonadales familia Pseudomonadaceae Azotobacteraceae genus Azomonas genus authority Winogradsky, 1938 subdivision ranks Species subdivision Azomonas agilis br Azomonas insignis br Azomonas macrocytogenes Azomonas are typically motile, oval to spherical, and secrete large quantities of Slime layer capsular slime . They are distinguished from Azotobacter by their inability to form cysts, but like Azotobacter they can biologically fix nitrogen under aerobic conditions diazotroph . Etymology The name Azomonas derives from New Latin noun azotum from Fr. noun azote from Ancient Greek language Greek prep. , a , not Ancient Greek language Greek noun , z , life N. Ancient Greek language Greek noun , az , not sustaining life , nitrogen New Latin pref. azo , pertaining to nitrogen Latin grammatical gender feminine gender noun monas monas , nominally meaning a unit , but in effect meaning a bacterium New Latin grammatical gender feminine gender noun Azomonas , nitrogen monad. ref name main lpsn a azomonas.html Azomonas ref Members of the genus Azomonas can be referred to as azomonads viz. Bacterial taxonomy Vernacular names Trivialisation of names . References references Category Pseudomonadales Proteobacteria stub es Azomonas uk Azomonas ... more details
italictitle Taxobox image image width image caption name regnum Bacteria phylum Cyanobacteria classis see http ijs.sgmjournals.org cgi content abstract 54 5 1895 proposal ordo Nostocales familia Nostocaceae genus Nostoc species N. punctiforme binomial Nostoc punctiforme Nostoc punctiforme is a species of filamentous cyanobacteria . Under non limiting nutritional environmental conditions, its filaments are composed of Photosynthesis photosynthetic vegetative cells upon nutrient limitation, some of these cells undergo Cell differentiation differentiation into Heterocyst heterocysts , Akinete akinetes or Hormogonium hormogonia ref name Meeks cite journal last Meeks first JC coauthors EL Campbell, ML Summers, FC Wong title Cellular differentiation in the cyanobacterium Nostoc punctiforme journal Arch Microbiol year 2002 volume 178 issue 6 pages 395 403 doi 10.1007 s00203 002 0476 5 url http www.springerlink.com content y12gjnj8hfjj48cb accessdate 11 December 2011 ref . N. punctiforme is one of the Nostoc strains able to maintain Diazotroph diazotrophic symbiosis with Vascular plant higher plants such as the bryophyte bryophytes Anthocerus punctatus and Blasia pusilla , water ferns from the genus Azolla , the cycads Macrozamia spp., and the angiosperm Gunnera ref name Meeks2 cite journal last Meeks first JC title Symbiosis between Nitrogen Fixing Cyanobacteria and Plants journal BioScience year 1998 volume 48 issue 4 pages 266 276 url http www.jstor.org stable 1313353 accessdate 11 December 2011 ref . References reflist External links http genome.jgi.doe.gov nospu nospu.home.html Genome sequencing project page of Nostoc punctiforme PCC 73102 Category Cyanobacteria bacteria stub cs Nostoc punctiforme ... more details
unreferenced date July 2009 File Centaurea maculosa.jpg thumb Centaurea maculosa , an example of pioneer species Pioneer species are species which Colonisation biology colonize previously uncolonized land, usually leading to ecological succession . They are the first organisms to start the chain of events leading to a livable biosphere or ecosystem . Since uncolonized land may have thin, poor quality soils with few nutrients, pioneer species are often hearty plants with adaptations such as long roots, root nodes containing Diazotroph nitrogen fixing bacteria , and leaves that employ transpiration . Pioneer species will die creating plant litter , and break down as leaf mold after some time, making new soil for secondary succession see below , and nutrients for small fish and aquatic plant s in adjacent bodies of water. Pioneer flora Pioneer species are often Poaceae grass es such as Ammophila Poaceae marram grass , which grows on sand dunes . In more rocky and damp conditions, they are usually lichen , and small ephemeral bunchgrass es and wildflower s in crevices. The plants, or anything that has the system of a plant, to be specially to the extremes that may be experienced, and once they have modified the environment may be out competed by less specific plants, eventually leading to a climax community . Examples of the plants and organism that colonize such areas are Barren sand Leymus Lyme grass Leymus arenarius , Agropyron Sea couch grass Agropyron pungens , Ammophila Poaceae Marram grass Ammophila breviligulata Salt water green algae , Zostera Marine eel grass Zostera Zostera spp. , Pickleweed Salicornia virginica , and Spartina Cordgrass hybrid Spartina townsendii and Spartina anglica . Clear water algae , mosses , Vallisneria Freshwater eel grass Vallisneria americana . Pioneer fauna Pioneering fauna are not responsible for initial colonisation of an area, but will colonize an area only flora and fungi previously inhabited, leading the way for others. A good ... more details
Taxobox image Desulfobacter hydrogenophilus viable cells.png image width 250px image caption Phase contrast micrograph of Desulfobacter hydrogenophilus viable cells . Bar 10 m. regnum Bacterium Bacteria phylum Proteobacteria classis Deltaproteobacteria ordo Desulfobacterales familia Desulfobacteraceae genus Desulfobacter species D. hydrogenophilus binomial Desulfobacter hydrogenophilus binomial authority Widdell, 1987 Desulfobacter hydrogenophilus is a strictly anaerobic sulfate reducing bacterium. ref name Widdel cite journal author F. Widdel year 1987 title New types of acetate oxidizing, sulfate reducing Desulfobacter species, D. hydrogenophilus sp. nov., D. latus sp. nov., and D. curvatus sp. nov. journal Archives of Microbiology volume 148 issue 4 pages 286 291 doi 10.1007 BF00456706 ref It was isolated and characterized in 1987 by Friedrich Widdel of the University of Konstanz Germany . Like most sulfate reducing bacteria SRB , D. hydrogenophilus is capable of completely oxidizing organic compounds specifically acetate , pyruvate and ethanol to carbon dioxide CO sub 2 sub , and therefore plays a key role in biomineralization in wikt anaerobic anaerobic marine environments. ref cite journal author Bo Barker J rgensen year 1982 title Mineralization of organic matter in the sea bed the role of sulphate reduction journal Nature journal Nature volume 296 issue 5858 pages 643 645 bibcode 1982Natur.296..643J doi 10.1038 296643a0 ref However, unlike many SRB, D. hydrogenophilus is a facultative lithoautotroph , and can grow using hydrogen H sub 2 sub as an electron donor and CO sub 2 sub as a carbon source. ref name Widdel D. hydrogenophilus is also unique because it is psychrophilic and has been shown to grow at temperatures as low as convert 0 C F disp or . It is also diazotroph ic, or capable of nitrogen fixation fixing nitrogen . ref name Widdel Cell structure Cells are elongated oval shaped, and 1 1.3 by 2 3 m in size Figure 1 . They are non motile, g ... more details
This table is designed to show the role s performed by each chemical element, in nature and in technology. Z Atomic number Sym. Chemical symbol Symbol Per. Period periodic table Period Gr. Group periodic table Group class wikitable sortable Z Sym. Element Per. Gr. Role s in nature br non living and living Role s in technology br old and new 1 H Hydrogen 1 1 Astronomy source of power by nuclear fusion proton proton chain reaction and CNO cycle br Biology CHON One of the most common elements in living organisms br Petrochemical industry hydrodealkylation , hydrodesulfurization br Various industries hydrogenation br 2 He Helium 1 18 Astronomy source of power by nuclear fusion alpha process and triple alpha process br Various industries cryogenics , pressurization , controlled atmosphere , welding 3 Li Lithium 2 1 Ceramics and glass flux, component of ovenware br Electricity and electronics battery electricity batteries br Various industries grease lubricant lubricating greases br 4 Be Beryllium 2 2 Radiography radiation windows br Aeronautics and astronautics lightweight structural components br 5 B Boron 2 13 Ceramics and glass borosilicate glass br Cleaning products detergent s and bleach es br Insecticide s boric acid br Electronics semiconductor s br 6 C Carbon 2 14 Biology CHON One of the most common elements in living organisms br See also Carbon based life Fossil fuel s coal , methane and petroleum br Textile industry cellulose br Metallurgy alloy s, especially carbon steel br 7 N Nitrogen 2 15 Bacteria and archaea nitrogen fixation by diazotroph s br All forms of life on earth essential component of amino acid s and of nucleic acid s br Earth s atmosphere, soil, and life forms nitrogen cycle br See also CHON . br Chemical industry ... more details
refimprove date April 2012 The Haber process , also called the Haber Bosch process , is the nitrogen fixation reaction of nitrogen gas and hydrogen gas , over an enriched iron or ruthenium Catalysis catalyst , which is used to industrially produce ammonia . ref name enriching Enriching the Earth Fritz Haber, Carl Bosch, and the Transformation of World Food Production by Vaclav Smil 2001 ISBN 0 262 19449 X ref ref name hager Hager, Thomas 2008 . The Alchemy of Air . Harmony Books, New York. ISBN 9780307351784. ref ref Fertilizer Industry Processes, Pollution Control and Energy Conservation by Marshall Sittig 1979 Noyes Data Corp., N.J. ISBN 0 8155 0734 8 ref ref Heterogeneous Catalysts A study Guide ref Despite the fact that 78.1 of the air we breathe is nitrogen , the gas is relatively unavailable because it is so unreactive nitrogen molecules are held together by strong Chemical bond triple bonds . It was not until the early 20th century that the Haber process was developed to harness the atmospheric abundance of nitrogen to create ammonia, which can then be redox oxidized to make the nitrate s and nitrite s essential for the production of nitrate fertilizers fertilizer and explosives . Prior to the discovery of the Haber process, ammonia had been difficult to produce on an industrial scale. The Haber process is important today because the fertilizer generated from ammonia is responsible for sustaining one third of the Earth s population. ref name autogenerated1 cite book last Wolfe first David W. title Tales from the underground a natural history of subterranean life year 2001 publisher Perseus Pub location Cambridge, Mass isbn 0738201286 oclc 46984480 ref It is estimated that half of the protein within human beings is made of nitrogen that was originally fixed by this process, the remainder was produced by Diazotroph nitrogen fixing bacteria and archaea . ref BBC Discovery Can Chemistry Save The World? 2. Fixing the Nitrogen Fix ref History Main History of the Ha ... more details
Taxobox image Klebsiella pneumoniae 01.png image width 240px image caption K. pneumoniae on a MacConkey agar MacConkey agar plate . regnum Bacteria phylum Proteobacteria classis Gamma Proteobacteria ordo Enterobacteriaceae Enterobacteriales familia Enterobacteriaceae genus Klebsiella species K. pneumoniae binomial Klebsiella pneumoniae binomial authority Schroeter 1886 br Trevisan 1887 Klebsiella pneumoniae is a Gram negative , non motile, Bacterial capsule encapsulated , lactose fermentation biochemistry fermenting , facultative anaerobic , rod shaped bacterium found in the normal flora of the mouth, skin, and intestines. ref name Sherris cite book author Ryan KJ Ray CG editors title Sherris Medical Microbiology edition 4th publisher McGraw Hill year 2004 isbn 0838585299 ref It is clinically the most important member of the Klebsiella genus of Enterobacteriaceae . Seven species of the Klebsiella genus, with demonstrated similarities in DNA homology are known. These are 1 Klebsiella pneumoniae , 2 Klebsiella ozaenae , 3 Klebsiella terrigena , 4 Klebsiella rhinoscleromatis , 5 Klebsiella oxytoca , 6 Klebsiella planticola , and 7 Klebsiella ornithinolytica . Of these, K oxytoca and K rhinoscleromatis have also been demonstrated in human clinical specimens. In recent years, klebsiellae have become important pathogens in nosocomial infections. It is closely related to Klebsiella oxytoca K. oxytoca from which it is distinguished by being indole test indole negative and by its ability to grow on both melezitose and 3 hydroxybutyrate . It naturally occurs in the soil, and about 30 of strains can nitrogen fixation fix nitrogen in anaerobic conditions. ref name Postgate 1998 cite book author Postgate J year 1998 title Nitrogen fixation, 3rd ed. publisher Cambridge University Press ref As a free living diazotroph , its nitrogen fixation system has been much studied. Members of the Klebsiella genus typically express 2 types of antigens on their cell surface. The first, O antig ... more details
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