Magnetotaxis is a process implemented by a diverse group of Gram-negative bacteria that involves orienting and coordinating movement in response to Earth's magnetic field.[1] This process is mainly carried out by microaerophilic and anaerobic bacteria found in aquatic environments such as salt marshes, seawater, and freshwater lakes.[2] By sensing the magnetic field, the bacteria are able to orient themselves towards environments with more favorable oxygen concentrations. This orientation towards more favorable oxygen concentrations allows the bacteria to reach these environments faster as opposed to random movement through Brownian motion.[3]
Magnetic bacteria (e.g. Magnetospirillum magnetotacticum) contain internal structures known as magnetosomes which are responsible for the process of magnetotaxis. After orienting to the magnetic field using the magnetosomes, the bacteria use flagella to swim along the magnetic field, towards the more favorable environment.[4] Magnetotaxis has no impact on the average speed of the bacteria.[3] However, magnetotaxis allows bacteria to guide their otherwise random movement. This process is similar in practice to aerotaxis, but governed by magnetic fields instead of oxygen concentrations.[5] Magnetotaxis and aerotaxis often function together, as bacteria can use both magnetotactic and aerotactic systems to find proper oxygen concentrations. This is referred to as magneto-aerotaxis.[6] By orienting towards the Earth's poles, marine bacteria are able to direct their movement downwards, towards the anaerobic/micro aerobic sediments. This allows bacteria to change metabolic environments, which can enable chemical cycles.[7]
Magnetosomesedit
Magnetosomes contain crystals - often magnetite (Fe3O4).[8] Some extremophile bacteria from sulfurous environments have been isolated with greigite (an iron-sulfide compound Fe3S4).[9] Some magnetotactic bacteria also contain pyrite (FeS2) crystals, possibly as a transformation product of greigite.[10] These crystals are contained within a bilayer membrane called the magnetosome membrane which is embedded with specific proteins. There are many different shapes of crystals. Crystal shape is typically consistent within a bacterial species.[2] The most common arrangement of magnetosomes is in chains which allows a maximum magnetic dipole moment to be created.[1] Within bacteria, there can be many chains of magnetosomes of different lengths that tend to align along the long axis of bacterial cell.[4] The dipole moment created from the chains of magnetosomes allows the bacteria to align with the magnetic field as they move.[1] Once magnetic bacteria die, they are able to orient themselves to the Earth's magnetic field but they are incapable of migrating along the field.[4]
Hemispheres and magnetic fieldsedit
In the northern hemisphere, north-seeking bacteria move downwards towards sediment (parallel to the magnetic field). In the southern hemisphere, south seeking bacteria dominate and move downwards toward the sediment (antiparallel to the magnetic field).[6] It was originally thought by scientists that south seeking bacteria would move upwards in the north hemisphere, towards very high concentrations of oxygen. This would negatively select south seeking bacteria; so that north seeking bacteria dominate in the northern hemisphere and vice versa. However, south-seeking bacteria have been found in the northern hemisphere. Additionally, both north and south seeking magnetic bacteria, are found even at the Earth's magnetic equator, where the field is directed horizontally.[1]
^ abcdLefevre, C. T.; Bazylinski, D. A. (4 September 2013). "Ecology, Diversity, and Evolution of Magnetotactic Bacteria". Microbiology and Molecular Biology Reviews. 77 (3): 497–526. doi:10.1128/MMBR.00021-13. PMC3811606. PMID 24006473.
^ abcFrankel, Richard B (2003). "Biological Permanent Magnets". Hyperfine Interactions. 151 (1): 145–153. Bibcode:2003HyInt.151..145F. doi:10.1023/B:HYPE.0000020407.25316.c3. S2CID 41997803.
^Bennet, Mathieu A.; Eder, Stephan H. K. (5 July 2016), Faivre, Damien (ed.), "Magnetoreception and Magnetotaxis", Iron Oxides (1 ed.), Wiley, pp. 567–590, doi:10.1002/9783527691395.ch22, ISBN978-3-527-33882-5, retrieved 24 April 2022
^Li, Jinhua; Liu, Peiyu; Wang, Jian; Roberts, Andrew P.; Pan, Yongxin (December 2020). "Magnetotaxis as an Adaptation to Enable Bacterial Shuttling of Microbial Sulfur and Sulfur Cycling Across Aquatic Oxic‐Anoxic Interfaces". Journal of Geophysical Research: Biogeosciences. 125 (12). Bibcode:2020JGRG..12506012L. doi:10.1029/2020JG006012. ISSN 2169-8953. S2CID 228886950.
^Lower, Brian H.; Bazylinski, Dennis A. (2013). "The Bacterial Magnetosome: A Unique Prokaryotic Organelle". Journal of Molecular Microbiology and Biotechnology. 23 (1–2): 63–80. doi:10.1159/000346543. ISSN 1660-2412. PMID 23615196. S2CID 25856024.
^Dusenbery, David B. (2009). Living at micro scale : the unexpected physics of being small. Cambridge, Mass.: Harvard University Press. ISBN9780674031166.
^Mann, Stephen; Sparks, Nicholas H. C.; Frankel, Richard B.; et al. (1990). "Biomineralization of ferrimagnetic greigite (Fe3S4) and iron pyrite (FeS2) in a magnetotactic bacterium". Nature. 343 (6255) (published 18 January 1990): 258–261. Bibcode:1990Natur.343..258M. doi:10.1038/343258a0. S2CID 4351424.
Further readingedit
Odenwald, Sten (15 March 2002). The 23rd Cycle. Columbia University Press. pp. 57–62. ISBN978-0231120791.
External linksedit
Magnetotaxis in bacteria
Do animals really use magnetism in any interesting way to navigate? (The Astronomy Cafe)
April 13, 2024
magnetotaxis, process, implemented, diverse, group, gram, negative, bacteria, that, involves, orienting, coordinating, movement, response, earth, magnetic, field, this, process, mainly, carried, microaerophilic, anaerobic, bacteria, found, aquatic, environment. Magnetotaxis is a process implemented by a diverse group of Gram negative bacteria that involves orienting and coordinating movement in response to Earth s magnetic field 1 This process is mainly carried out by microaerophilic and anaerobic bacteria found in aquatic environments such as salt marshes seawater and freshwater lakes 2 By sensing the magnetic field the bacteria are able to orient themselves towards environments with more favorable oxygen concentrations This orientation towards more favorable oxygen concentrations allows the bacteria to reach these environments faster as opposed to random movement through Brownian motion 3 Contents 1 Overview 2 Magnetosomes 3 Hemispheres and magnetic fields 4 See also 5 Notes and references 6 Further reading 7 External linksOverview editMagnetic bacteria e g Magnetospirillum magnetotacticum contain internal structures known as magnetosomes which are responsible for the process of magnetotaxis After orienting to the magnetic field using the magnetosomes the bacteria use flagella to swim along the magnetic field towards the more favorable environment 4 Magnetotaxis has no impact on the average speed of the bacteria 3 However magnetotaxis allows bacteria to guide their otherwise random movement This process is similar in practice to aerotaxis but governed by magnetic fields instead of oxygen concentrations 5 Magnetotaxis and aerotaxis often function together as bacteria can use both magnetotactic and aerotactic systems to find proper oxygen concentrations This is referred to as magneto aerotaxis 6 By orienting towards the Earth s poles marine bacteria are able to direct their movement downwards towards the anaerobic micro aerobic sediments This allows bacteria to change metabolic environments which can enable chemical cycles 7 Magnetosomes editMagnetosomes contain crystals often magnetite Fe3O4 8 Some extremophile bacteria from sulfurous environments have been isolated with greigite an iron sulfide compound Fe3S4 9 Some magnetotactic bacteria also contain pyrite FeS2 crystals possibly as a transformation product of greigite 10 These crystals are contained within a bilayer membrane called the magnetosome membrane which is embedded with specific proteins There are many different shapes of crystals Crystal shape is typically consistent within a bacterial species 2 The most common arrangement of magnetosomes is in chains which allows a maximum magnetic dipole moment to be created 1 Within bacteria there can be many chains of magnetosomes of different lengths that tend to align along the long axis of bacterial cell 4 The dipole moment created from the chains of magnetosomes allows the bacteria to align with the magnetic field as they move 1 Once magnetic bacteria die they are able to orient themselves to the Earth s magnetic field but they are incapable of migrating along the field 4 Hemispheres and magnetic fields editIn the northern hemisphere north seeking bacteria move downwards towards sediment parallel to the magnetic field In the southern hemisphere south seeking bacteria dominate and move downwards toward the sediment antiparallel to the magnetic field 6 It was originally thought by scientists that south seeking bacteria would move upwards in the north hemisphere towards very high concentrations of oxygen This would negatively select south seeking bacteria so that north seeking bacteria dominate in the northern hemisphere and vice versa However south seeking bacteria have been found in the northern hemisphere Additionally both north and south seeking magnetic bacteria are found even at the Earth s magnetic equator where the field is directed horizontally 1 See also editMagnetoception Magnetotactic bacteriaNotes and references edit a b c d Lefevre C T Bazylinski D A 4 September 2013 Ecology Diversity and Evolution of Magnetotactic Bacteria Microbiology and Molecular Biology Reviews 77 3 497 526 doi 10 1128 MMBR 00021 13 PMC 3811606 PMID 24006473 a b Yan Lei Zhang Shuang Chen Peng Liu Hetao Yin Huanhuan Li Hongyu October 2012 Magnetotactic bacteria magnetosomes and their application Microbiological Research 167 9 507 519 doi 10 1016 j micres 2012 04 002 PMID 22579104 a b Smith M J Sheehan P E Perry L L O Connor K Csonka L N Applegate B M Whitman L J August 2006 Quantifying the Magnetic Advantage in Magnetotaxis Biophysical Journal 91 3 1098 1107 Bibcode 2006BpJ 91 1098S doi 10 1529 biophysj 106 085167 PMC 1563769 PMID 16714352 a b c Frankel Richard B 2003 Biological Permanent Magnets Hyperfine Interactions 151 1 145 153 Bibcode 2003HyInt 151 145F doi 10 1023 B HYPE 0000020407 25316 c3 S2CID 41997803 Bennet Mathieu A Eder Stephan H K 5 July 2016 Faivre Damien ed Magnetoreception and Magnetotaxis Iron Oxides 1 ed Wiley pp 567 590 doi 10 1002 9783527691395 ch22 ISBN 978 3 527 33882 5 retrieved 24 April 2022 a b Encyclopedia of microbiology Moselio Schaechter 3rd ed Amsterdam Elsevier 2009 ISBN 978 0 12 373944 5 OCLC 399645273 a href Template Cite book html title Template Cite book cite book a CS1 maint others link Li Jinhua Liu Peiyu Wang Jian Roberts Andrew P Pan Yongxin December 2020 Magnetotaxis as an Adaptation to Enable Bacterial Shuttling of Microbial Sulfur and Sulfur Cycling Across Aquatic Oxic Anoxic Interfaces Journal of Geophysical Research Biogeosciences 125 12 Bibcode 2020JGRG 12506012L doi 10 1029 2020JG006012 ISSN 2169 8953 S2CID 228886950 Lower Brian H Bazylinski Dennis A 2013 The Bacterial Magnetosome A Unique Prokaryotic Organelle Journal of Molecular Microbiology and Biotechnology 23 1 2 63 80 doi 10 1159 000346543 ISSN 1660 2412 PMID 23615196 S2CID 25856024 Dusenbery David B 2009 Living at micro scale the unexpected physics of being small Cambridge Mass Harvard University Press ISBN 9780674031166 Mann Stephen Sparks Nicholas H C Frankel Richard B et al 1990 Biomineralization of ferrimagnetic greigite Fe3S4 and iron pyrite FeS2 in a magnetotactic bacterium Nature 343 6255 published 18 January 1990 258 261 Bibcode 1990Natur 343 258M doi 10 1038 343258a0 S2CID 4351424 Further reading editOdenwald Sten 15 March 2002 The 23rd Cycle Columbia University Press pp 57 62 ISBN 978 0231120791 External links editMagnetotaxis in bacteria Do animals really use magnetism in any interesting way to navigate The Astronomy Cafe Retrieved from https en wikipedia org w index php title Magnetotaxis amp oldid 1161078967, wikipedia, wiki, book, books, library,
