Assignment 3
editOriginal- "Shewanella"
Diet
editShewanella species respire a variety of electrons acceptors in anoxic conditions, many of which are located extracellularly. The mechanism for extracellular electron transfer involves c-type cytochromes that span the inner and outer membranes and "bacterial nanowires".[1]
References
edit- ^ Powell, Corey S. (January 21, 2015). "Have We Found Alien Life?". Popular Science. Retrieved 2015-10-26.
Edits- "Shewanella"
Metabolism
editCurrently discovered Shewanella species are heterotrophic facultative anaerobes.[1] In the absence of oxygen, members of this genus may use a variety of other electron acceptors for respiration. These include thiosulfate, sulfite, or elemental sulfur[2], as well as fumarate.[3] Some members of this species, most notably Shewanella oneidensis, have the ability to respire extracellular insoluble manganese and iron oxides using bacterial nanowires.[4] Some of the more unique modes of respiration are being studied for their potentially useful applications. The metal respiring capabilities can potentially be applied to bioremediation of uranium-contaminated groundwater,[5] as well as the creation of microbial fuel cells.[6]
References
edit- ^ Serres, Genomic Analysis of Carbon Source Metabolism of Shewanella oneidensis MR-1: Predictions versus Experiments, Journal of Bacteriology, July 2006
- ^ Burns, Anaerobic Respiration of Elemental Sulfur and Thiosulfate by Shewanella oneidensis MR-1 Requires psrA, a Homolog of the phsA Gene of Salmonella enterica Serovar Typhimurium LT2, Applied and Enviromental Microbiology, 19 June 2009
- ^ Pinchuk et al., Pyruvate and lactate metabolism by Shewanella oneidensis MR-1 under fermentation, oxygen limitation, and fumarate respiration conditions., Applied and Enviromental Microbiology December 2011
- ^ Tiedje, [http://www.nature.com/nbt/journal/v20/n11/full/nbt1102-1093.html?foxtrotcallback=true, Shewanella—the environmentally versatile genome ], Nature Biotechnology, 2002
- ^ Newsome, The biogeochemistry and bioremediation of uranium and other priority radionuclides, Chemical Geology, Volume 363, pp 164-184, 10 Jan 2014,
- ^ Hoffman et al., Dual-chambered bio-batteries using immobilized mediator electrodes, Journal of Applied Electrochemistry, Vol 43, Issue 7, pp 629–636, 27 Apr 2013
Assignment 5
editMetabolism
editCurrently known Shewanella species are heterotrophic facultative anaerobes.[1] In the absence of oxygen, members of this genus possess capabilities allowing the use of a variety of other electron acceptors for respiration. These include thiosulfate, sulfite, or elemental sulfur[2], as well as fumarate.[3] Marine species have demonstrated an ability to use arsenic as an electron acceptor as well. [4] Some members of this species, most notably Shewanella oneidensis, have the ability to respire through a wide range of metal species, including manganese, chromium, uranium, and iron.[5] Reduction of iron and manganese through Shewanella respiration has been shown to involve extracellular electron transfer through the employment of bacterial nanowires, extensions of the outer membrane. [6]
Applications
editThe discovery of some of the respiratory capabilities possessed by members of this genus has opened the door to possible applications for these bacteria. The metal-reducing capabilities can potentially be applied to bioremediation of uranium-contaminated groundwater,[7] with the reduced form of uranium produced being easier to remove from water than the more soluble uranium oxide. Scientists researching the creation of microbial fuel cells, designs that use bacteria to induce a current, have also made use of the metal reducing capabilities some species of Shewanella possess as a part of their metabolic repertoire.[8]
References
edit- ^ Serres, Genomic Analysis of Carbon Source Metabolism of Shewanella oneidensis MR-1: Predictions versus Experiments, Journal of Bacteriology, July 2006
- ^ Burns, Anaerobic Respiration of Elemental Sulfur and Thiosulfate by Shewanella oneidensis MR-1 Requires psrA, a Homolog of the phsA Gene of Salmonella enterica Serovar Typhimurium LT2, Applied and Enviromental Microbiology, 19 June 2009
- ^ Pinchuk et al., Pyruvate and lactate metabolism by Shewanella oneidensis MR-1 under fermentation, oxygen limitation, and fumarate respiration conditions., Applied and Enviromental Microbiology December 2011
- ^ Saltikov et al., Expression Dynamics of Arsenic Respiration and Detoxification in Shewanella sp. Strain ANA-3, Journal of Bacteriology, Nov 2005
- ^ Tiedje, [https://www.nature.com/articles/nbt1102-1093#ref2, Shewanella—the environmentally versatile genome], Nature Biotechnology
- ^ Pirbadian et al., Bacterial Nanowires of Shewanella Oneidensis MR-1 are Outer Membrane and Periplasmic Extensions of the Extracellular Electron Transport Components, Biophysical Journal, Volume 108, Jan 2015
- ^ Newsome, The biogeochemistry and bioremediation of uranium and other priority radionuclides, Chemical Geology, Volume 363, pp 164-184, 10 Jan 2014,
- ^ Hoffman et al., Dual-chambered bio-batteries using immobilized mediator electrodes, Journal of Applied Electrochemistry, Vol 43, Issue 7, pp 629–636, 27 Apr 2013