https://microbewiki.kenyon.edu/api.php?action=feedcontributions&user=Jujublah311&feedformat=atommicrobewiki - User contributions [en]2024-03-29T15:52:07ZUser contributionsMediaWiki 1.39.6https://microbewiki.kenyon.edu/index.php?title=Desulfuromonas_acetoxidans&diff=78815Desulfuromonas acetoxidans2012-12-15T01:43:14Z<p>Jujublah311: </p>
<hr />
<div>==Classification==<br />
[[File:classification.jpeg|340px|thumb|right|FIGURE 1. hylogenetic tree based on 16s rRNA. Modified by adding a red box around ''desulfuromonas acetoxidans''. Source: http://www.sciencedirect.com/science/article/pii/S0964830510001721 P]]<br />
===Higher order taxa===<br />
<br />
<br />
Kingdom: [http://en.wikipedia.org/wiki/Bacteria Bacteria]<br />
<br />
Phylum: [http://en.wikipedia.org/wiki/Proteobacteria Proteobacteria]<br />
<br />
Class: [http://en.wikipedia.org/wiki/Deltaproteobacteria Deltaproteobacteria]<br />
<br />
Order: [http://en.wikipedia.org/wiki/Desulfuromonadales Desulfuromonadales]<br />
<br />
Family: Desulfuromonadaceae<br />
<br />
Genus: [[Desulfuromonas]]<br />
[7]<br />
<br />
<br />
<br />
<br />
===Species===<br />
{|<br />
| height="10" bgcolor="#FFDF95" |<br />
'''NCBI: [http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=281689 Taxonomy]'''<br />
|}<br />
<br />
Species: ''Acetoxidans'' [7]<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
==Description and significance==<br />
''Desulfuromonas acetoxidans'' was first described in 1976 by N. Pfennig and H. Biebl [10]. The name has a Latin root, meaning “single-celled organism that reduces [http://en.wikipedia.org/wiki/Sulfur sulphur] (''Desulfuromonas'') and oxidizes [http://en.wikipedia.org/wiki/Acetate acetate] (''acetoxidans'')” [6, 10]. It was first described as a sulphur reducing bacteria capable of [http://en.wikipedia.org/wiki/Anaerobic_respiration anaerobically] reducing sulphur to [http://en.wikipedia.org/wiki/Sulfide sulphide] [10]. However, it was later discovered to also possess the ability to perform dissimilatory Fe(III) reduction coupled with the oxidation of organic compounds [11].<br />
<br />
''Desulfuromonas acetoxidans'' is a rod-shaped, [http://en.wikipedia.org/wiki/Gram-negative_bacteria Gram negative] bacterium that is predominantly found in marine sediments [10], though able to survive in fresh water environments [13]. The species is a strict anaerobe that uses a variety of electron donors, such as acetate, ethanol, propanol and butanol, to yield energy [10].<br />
<br />
''Desulfuromonas acetoxidans'' is part of the ''Desulfuromonas'' genus, which has a characteristic of being able to reduce sulphur through the conversion of elemental sulphur into sulphide [10]. ''D. acetoxidans'' is the first species described within the ''Desulfuromonas'' genus, and it is also the first marine microorganism ever described to support growth through Fe(III) or Mn(IV) reduction coupled to the oxidation of organic compounds [11]. <br />
<br />
As the first marine organism ever described to perform the oxidation of organic material coupled with reduction of Fe(III) or Mn(IV), ''D. acetoxidans'' has served as a model organism for the mechanism of Fe(III) or Mn(IV) oxidation of organic compounds [11]. <br />
<br />
<br />
==Genome structure==<br />
The genome sequence of ''D. acetoxidans'' was completed in 2007 with funding from the United states Department of Energy Joint Genome Institute [5]. The sequence is available [http://img.jgi.doe.gov/cgi-bin/w/main.cgi?section=TaxonDetail&taxon_oid=638341078 online] [7], though a formal description of the genome sequence has not been published in a peer-reviewed scientific journal. Its genome is 3.8Mb in length, and codes for 3234 putative genes [7]. A recent study has shown that the genome contains a very large number of genes coding for [http://en.wikipedia.org/wiki/Cytochrome_c c-type cytochromes] with multiple [http://en.wikipedia.org/wiki/Heme heme cofactors] [1]. Studies have found that the genome of ''D. acetoxidans'' codes for 47 possible multiheme cytochrome proteins [3]. A heme cofactor is a prosthetic group found on proteins that have diverse function [5]. In the case of c-type cytochrome, the heme cofactors function as both electron acceptors and electron donors [5]. The large percentage of genes coding for c-type cytochromes have been found to correlate with the ability of ''D. acetoxidans'' to reduce Fe(III) through the dissimilatory pathway [2]. In a study done by Aubert et al. (date, i.e. 2007), the genes that coded for the c-type cytochromes were inserted into the genome of the closely related [http://en.wikipedia.org/wiki/Desulfovibrio ''Desulfovibrio''] ''desulfuricans'', which is unable to reduce metals [3]. The transformed ''D. desulfuricans'' produced the c-type cytochromes and exhibited metal reductase activities [3]. This shows that the c-type cytochrome is vital in the reduction of Fe(III) or Mn(IV) in ''D. acetoxidans''. The mechanistic details concerning how these multiheme cytochromes work are still being studied, but C7 cytochrome is proposed to possess metal reductase activity [2].<br />
<br />
<br />
==Cell structure, metabolism and life cycle==<br />
[[File:Acetoxidanflagellum.jpeg|150px|thumb|left|FIGURE 2: Electron Microscopy of ''Desulfuromonas acetoxidans'' that clearly shows the flagellum at the lateral side of cell body. Source: http://garciajeanlouis9051.perso.neuf.fr/aaBXIII4_O4_5.html]]<br />
[[File:Cellwall.gif|375px|thumb|right|FIGURE 3. A figure visualizing the differences between Gram positive and Gram negative cell walls. Source: http://water.me.vccs.edu/courses/env108/Lesson5_print.htm]]<br />
<br />
<br />
<br />
''D.acetoxidans'' has the following characteristics: i) dimensions of 0.4 - 0.7μm in width and 1 - 4μm in length, ii) a single [http://en.wikipedia.org/wiki/Flagellum flagellum] on the lateral side of the rod-shaped bacteria and even though it possesses a flagellum, most strains were not motile (figure 2.) [10]. Its cell envelope resembles those of other gram negative bacteria, with an outer membrane separated from the cytoplasmic membrane by a thin layer of [http://en.wikipedia.org/wiki/Peptidoglycan peptidoglycan] (figure 3.) [10]. ''D. acetoxidans'' have been found to be non-sporulating, free living bacterium that divides via [http://en.wikipedia.org/wiki/Fission_(biology)#Binary_fission_of_prokaryotes binary fission] [10].<br />
<br />
<br />
<br />
''D. acetoxidans'' possesses a complex metabolism, and energy for [http://en.wikipedia.org/wiki/Metabolism metabolism] comes from a variety of redox reactions. They are [http://en.wikipedia.org/wiki/Chemoorganotroph chemoorganotrophs] that respire anaerobically, using acetate, ethanol or propanol as carbon sources and electron donors in the presence of ~0.2mM bicarbonate [10]. These organic carbon sources are completely oxidized to CO2 [6, 10]. When ''D. acetoxidans'' is reducing sulphuric compounds, either elemental sulphur or disulfide bonds within compounds such as malate or fumarate serve as electron acceptors and are reduced to H2S and sulfhydryl-groups, respectively[10]. <br />
<br />
<br />
<br />
''D. acetoxidans'', when present in different media, has different cytochromes that are present as the dominant type, but there is one type (C7 cytochrome) that is always present, suggesting that this cytochrome plays a key role in metabolism [2]. Studies have also shown that cytochrome C7 plays a role as an electron-transfer protein in the sulphur reduction, as well as in reduction of Fe(III) and Mn(IV) [2]. <br />
<br />
<br />
<br />
<br />
<br />
<br />
==Ecology==<br />
[[File:Cyclegreenbact.png|375px|thumb|right|FIGURE 4: Original figure: Schematic diagram showing the mutualism between Green sulfur bacteria and ''Desulfuromonas acetoxidans''.]]<br />
<br />
<br />
<br />
''Desulfuromonas acetoxidans'' is found primarily in anoxic marine sediment, and rarely found in freshwater sediments [13]. It is able to grow in a pH-range of 6.5 to 8.5, but its optimum pH between 7.2 and 7.5 [10]. ''D. acetoxidans'' has an optimum growth temperature of ~30。C, but it can grow in temperature ranging from 25。C to 35。C [10]. In some environments, ''D. acetoxidans'' grows syntrophically with green sulphur bacteria [4, 8]. Their relationship is mutualistic in that the [http://en.wikipedia.org/wiki/Green_sulfur_bacteria green sulphur bacteria] presents dissolved and readily metabolizable form of sulphur which is used by ''D. acetoxidans'' (refer to figure). The sulphur is oxidized by ''D. acetoxidans'' to sulphur, which the green sulphur bacteria can use, this is shown schematically by Figure 4 [4, 12].<br />
<br />
<br />
<br />
The species has biogeochemical significance as it plays a role in the carbon and sulphur cycles [8]. In carbon contaminant-filled sediments, the environment usually quickly becomes anaerobic. As the environment becomes increasingly anoxic, Fe(III) becomes the most abundant and favourable electron acceptor for organic matter oxidation [8]. ''D. acetoxidans’'' ability to perform dissimilatory Fe(III) reduction can be coupled with the oxidation of organic contaminants, effectively removing them from the environment [8]. Recent studies are focused on the dissimilatory Fe(III) reduction aspect of ''D. acetoxidans'' rather than the sulphur reduction, since Fe(III) reduction signifies the production of electricity through the degradation of organic materials. This has been applied to the creation of [http://en.wikipedia.org/wiki/Microbial_fuel_cell microbial fuel cells], providing enough electricity to power basic electronic equipments [9].<br />
<br />
<br />
<br />
<br />
==References==<br />
[1] [http://www.ncbi.nlm.nih.gov/pubmed/21298162 Alves, A. S., Paquete, C. M., Fonseca, B. M., and Louro, R. O. “Exploration of the ‘cytochrome’ of ''Desulfuromonas acetoxidans'', a Marine Bacterium Capable of Powering Microbial Fuel Cells.” Metallomics, 2011, 3. p. 349–353. DOI: 10.1039/c0mt00084a]<br />
<br />
[2] [http://www.ncbi.nlm.nih.gov/pubmed/12119407 Assfalg, M., Bertini, I., Bruschi, M., Michel, C., and Turano, P. “The Metal Reductase Activity of Some Multiheme Cytochromes c: NMR Structural Characterization of the Reduction of Chromium(VI) to Chromium(III) by Cytochrome C7.” PNAS. 2002, DOI:10.1073.]<br />
<br />
[3] [http://www.ncbi.nlm.nih.gov/pubmed/9546165 Aubert, C., Lojou, E., Bianco, P., Rousset, M., Durand, M., Bruschi, M., and Dolla, A. “The Desulfuromonas acetoxidans Triheme Cytochrome C7 Produced in ''Desulfovibrio desulfuricans'' Retains Its Metal Reductase Activity.” Appl. Environ. Microbiol. 1998, 64(4):1308.]<br />
<br />
[4] [http://link.springer.com/article/10.1007%2FBF00689344?LI=true Biebl. H., Pfennig, N. “Growth Yields of Green Sulfur Bacteria in Mixed Cultures with Sulfur and Sulfate Reducing Bacteria.” Arch. Microbiol. 1978. 117, p. 9 -16.]<br />
<br />
[5] [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC361918/ Dumont, M. E., Cardillo, T. S., Hayes, M. K. and Sherman, F. “Role of cytochrome c heme lyase in mitochondrial import and accumulation of cytochrome c in Saccharomyces cerevisiae.” Mol Cell Biol. 1991 November; 11(11): 5487–5496. PMCID: PMC361918.]<br />
<br />
[6] [http://link.springer.com/article/10.1007%2FBF00428855?LI=true Gebhard , N. A., Thauer, R. K., Linder, D., Kaulfers, P., Pfennig, N. “Mechanism of acetate oxidation to CO2 with elemental sulfur in ''Desulfuromonas acetoxidans''.” Arch Microbiol (1985) 141:392-98.]<br />
<br />
[7] [http://www.ncbi.nlm.nih.gov/pubmed/21896772 Gillespie, J. J., Wattam, A. R., Cammer, S. A., Gabbard, J., Shukla, M. P., Dalay, O., Driscoll, T., Hix, D., Mane, S. P., Mao, C., Nordberg, E. K., Scott, M., Schulman, J. R., Snyder, E. E., Sullivan, D. E. Wang, C., Warren, A., Williams, K. P., Xue, T., Yoo, H. S., Zhang, C., Zhang, Y., Will, R., Kenyon, R.W. and Sobral B. W. (2011). “PATRIC: The Comprehensive Bacterial Bioinformatics Resource with a Focus on Human Pathogenic Species” Infect. Immun 79 (11): 4286-98. doi:10.1128/IAI.00207-11. PMID21896772.PMC3257917.]<br />
<br />
[8] [http://www.geobacter.org/publication-files/ASM_News_2002.pdf Lovley, D. R. “ Dissimilatory Metal Reduction: from Early Life to Bioremediation.” ASM News. 2002, 68(5). p. 231-37]<br />
<br />
[9] [http://www.geobacter.org/publication-files/Microbe_July_2006.pdf Lovley, D. R. “Microbial Energizers: Fuel Cells That Keep on Going.” Microbe. 2006, 1(6). p. 323-29.]<br />
<br />
[10] [http://www.ncbi.nlm.nih.gov/pubmed/1015937 Pfennig, N., and Biebl, H.. “''Desulfuromonas acetoxidans'' gen. nov. and sp. nov., a new anaerobic, sulfur-reducing, acetate-oxidizing bacterium.” Arch. Microbiol0., 1976, 110:3-12]<br />
<br />
[11] [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC202183/ Roden, E. R., Lovley, D. R. “Dissimilatory Fe(III) Reduction by the Marine Microorganism ''Desulfuromonas acetoxidans''.” Applied and Environmental Microbiology. 1993, 59(3). p. 734-42.]<br />
<br />
[12] [http://link.springer.com/article/10.1007%2FBF00248679?LI=true Warthmann, R., Cypionka, H., Pfennig, N. “Photoproduction of H2 from acetate by syntrophic cocultures of green sulfur bacteria and sulfur-reducing bacteria.” Arch Microbiol (1992), 157: 343-48.]<br />
<br />
[13] [http://www.ncbi.nlm.nih.gov/pubmed/16627667 Vandieken, V., Mußmann, B., Niemann, H., Jørgensen, B. B. “''Desulfuromonas svalbardensis'' sp. nov. and ''Desulfuromusa ferrireducens'' sp. nov., psychrophilic, Fe(III)-reducing bacteria isolated from Arctic sediments, Svalbard.” International Journal of Systematic and Evolutionary Microbiology (2006), 56: 1133–1139 DOI 10.1099.]</div>Jujublah311https://microbewiki.kenyon.edu/index.php?title=File:Cyclegreenbact.png&diff=78813File:Cyclegreenbact.png2012-12-15T01:37:36Z<p>Jujublah311: Jujublah311 uploaded a new version of &quot;File:Cyclegreenbact.png&quot;</p>
<hr />
<div>original figure showing the mutualism between Green sulfur bacteria and Desulfuromonas acetoxidans</div>Jujublah311https://microbewiki.kenyon.edu/index.php?title=Desulfuromonas_acetoxidans&diff=78812Desulfuromonas acetoxidans2012-12-15T01:36:51Z<p>Jujublah311: </p>
<hr />
<div>==Classification==<br />
[[File:classification.jpeg|340px|thumb|right|FIGURE 1. Source: http://www.sciencedirect.com/science/article/pii/S0964830510001721 Phylogenetic tree based on 16s rRNA. Modified by adding a red box around desulfuromonas acetoxidans.]]<br />
===Higher order taxa===<br />
Kingdom: [http://en.wikipedia.org/wiki/Bacteria Bacteria]<br />
<br />
Phylum: [http://en.wikipedia.org/wiki/Proteobacteria Proteobacteria]<br />
<br />
Class: [http://en.wikipedia.org/wiki/Deltaproteobacteria Deltaproteobacteria]<br />
<br />
Order: [http://en.wikipedia.org/wiki/Desulfuromonadales Desulfuromonadales]<br />
<br />
Family: Desulfuromonadaceae<br />
<br />
Genus: [[Desulfuromonas]]<br />
[7]<br />
<br />
<br />
<br />
<br />
<br />
===Species===<br />
{|<br />
| height="10" bgcolor="#FFDF95" |<br />
'''NCBI: [http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=281689 Taxonomy]'''<br />
|}<br />
<br />
Species: ''Acetoxidans'' [7]<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
==Description and significance==<br />
''Desulfuromonas acetoxidans'' was first described in 1976 by N. Pfennig and H. Biebl [10]. The name has a Latin root, meaning “single-celled organism that reduces [http://en.wikipedia.org/wiki/Sulfur sulphur] (''Desulfuromonas'') and oxidizes [http://en.wikipedia.org/wiki/Acetate acetate] (''acetoxidans'')” [6, 10]. It was first described as a sulphur reducing bacteria capable of [http://en.wikipedia.org/wiki/Anaerobic_respiration anaerobically] reducing sulphur to [http://en.wikipedia.org/wiki/Sulfide sulphide] [10]. However, it was later discovered to also possess the ability to perform dissimilatory Fe(III) reduction coupled with the oxidation of organic compounds [11].<br />
<br />
''Desulfuromonas acetoxidans'' is a rod-shaped, [http://en.wikipedia.org/wiki/Gram-negative_bacteria Gram negative] bacterium that is predominantly found in marine sediments [10], though able to survive in fresh water environments [13]. The species is a strict anaerobe that uses a variety of electron donors, such as acetate, ethanol, propanol and butanol, to yield energy [10].<br />
<br />
''Desulfuromonas acetoxidans'' is part of the ''Desulfuromonas'' genus, which has a characteristic of being able to reduce sulphur through the conversion of elemental sulphur into sulphide [10]. ''D. acetoxidans'' is the first species described within the ''Desulfuromonas'' genus, and it is also the first marine microorganism ever described to support growth through Fe(III) or Mn(IV) reduction coupled to the oxidation of organic compounds [11]. <br />
<br />
As the first marine organism ever described to perform the oxidation of organic material coupled with reduction of Fe(III) or Mn(IV), ''D. acetoxidans'' has served as a model organism for the mechanism of Fe(III) or Mn(IV) oxidation of organic compounds [11]. <br />
<br />
<br />
==Genome structure==<br />
The genome sequence of ''D. acetoxidans'' was completed in 2007 with funding from the United states Department of Energy Joint Genome Institute [5]. The sequence is available [http://img.jgi.doe.gov/cgi-bin/w/main.cgi?section=TaxonDetail&taxon_oid=638341078 online] [7], though a formal description of the genome sequence has not been published in a peer-reviewed scientific journal. Its genome is 3.8Mb in length, and codes for 3234 putative genes [7]. A recent study has shown that the genome contains a very large number of genes coding for [http://en.wikipedia.org/wiki/Cytochrome_c c-type cytochromes] with multiple [http://en.wikipedia.org/wiki/Heme heme cofactors] [1]. Studies have found that the genome of ''D. acetoxidans'' codes for 47 possible multiheme cytochrome proteins [3]. A heme cofactor is a prosthetic group found on proteins that have diverse function [5]. In the case of c-type cytochrome, the heme cofactors function as both electron acceptors and electron donors [5]. The large percentage of genes coding for c-type cytochromes have been found to correlate with the ability of ''D. acetoxidans'' to reduce Fe(III) through the dissimilatory pathway [2]. In a study done by Aubert et al. (date, i.e. 2007), the genes that coded for the c-type cytochromes were inserted into the genome of the closely related [http://en.wikipedia.org/wiki/Desulfovibrio ''Desulfovibrio''] ''desulfuricans'', which is unable to reduce metals [3]. The transformed ''D. desulfuricans'' produced the c-type cytochromes and exhibited metal reductase activities [3]. This shows that the c-type cytochrome is vital in the reduction of Fe(III) or Mn(IV) in ''D. acetoxidans''. The mechanistic details concerning how these multiheme cytochromes work are still being studied, but C7 cytochrome is proposed to possess metal reductase activity [2].<br />
<br />
<br />
==Cell structure, metabolism and life cycle==<br />
[[File:Acetoxidanflagellum.jpeg|150px|thumb|left|FIGURE 2: Electron Microscopy of Desulfuromonas acetoxidans that clearly shows the flagellum at the lateral side of cell body. Source: http://garciajeanlouis9051.perso.neuf.fr/aaBXIII4_O4_5.html]]<br />
[[File:Cellwall.gif|375px|thumb|right|FIGURE 3. A figure visualizing the differences between Gram positive and Gram negative cell walls. Source: http://water.me.vccs.edu/courses/env108/Lesson5_print.htm]]<br />
<br />
<br />
<br />
''D.acetoxidans'' has the following characteristics: i) dimensions of 0.4 - 0.7μm in width and 1 - 4μm in length, ii) a single [http://en.wikipedia.org/wiki/Flagellum flagellum] on the lateral side of the rod-shaped bacteria and even though it possesses a flagellum, most strains were not motile (figure 2.) [10]. Its cell envelope resembles those of other gram negative bacteria, with an outer membrane separated from the cytoplasmic membrane by a thin layer of [http://en.wikipedia.org/wiki/Peptidoglycan peptidoglycan] (figure 3.) [10]. ''D. acetoxidans'' have been found to be non-sporulating, free living bacterium that divides via [http://en.wikipedia.org/wiki/Fission_(biology)#Binary_fission_of_prokaryotes binary fission] [10].<br />
<br />
<br />
<br />
''D. acetoxidans'' possesses a complex metabolism, and energy for [http://en.wikipedia.org/wiki/Metabolism metabolism] comes from a variety of redox reactions. They are [http://en.wikipedia.org/wiki/Chemoorganotroph chemoorganotrophs] that respire anaerobically, using acetate, ethanol or propanol as carbon sources and electron donors in the presence of ~0.2mM bicarbonate [10]. These organic carbon sources are completely oxidized to CO2 [6, 10]. When ''D. acetoxidans'' is reducing sulphuric compounds, either elemental sulphur or disulfide bonds within compounds such as malate or fumarate serve as electron acceptors and are reduced to H2S and sulfhydryl-groups, respectively[10]. <br />
<br />
<br />
<br />
''D. acetoxidans'', when present in different media, has different cytochromes that are present as the dominant type, but there is one type (C7 cytochrome) that is always present, suggesting that this cytochrome plays a key role in metabolism [2]. Studies have also shown that cytochrome C7 plays a role as an electron-transfer protein in the sulphur reduction, as well as in reduction of Fe(III) and Mn(IV) [2]. <br />
<br />
<br />
<br />
==Ecology==<br />
[[File:Cyclegreenbact.png|375px|thumb|right|FIGURE 4: Original figure: A schematic diagram of how desulfuromonas acetoxidans and green sulphur bacteria work in their mutualistic relationship]]<br />
''Desulfuromonas acetoxidans'' is found primarily in anoxic marine sediment, and rarely found in freshwater sediments [13]. It is able to grow in a pH-range of 6.5 to 8.5, but its optimum pH between 7.2 and 7.5 [10]. ''D. acetoxidans'' has an optimum growth temperature of ~30。C, but it can grow in temperature ranging from 25。C to 35。C [10]. In some environments, ''D. acetoxidans'' grows syntrophically with green sulphur bacteria [4, 8]. Their relationship is mutualistic in that the [http://en.wikipedia.org/wiki/Green_sulfur_bacteria green sulphur bacteria] presents dissolved and readily metabolizable form of sulphur which is used by ''D. acetoxidans'' (refer to figure). The sulphur is oxidized by ''D. acetoxidans'' to sulphur, which the green sulphur bacteria can use, this is shown schematically by Figure 4 [4, 12].<br />
The species has biogeochemical significance as it plays a role in the carbon and sulphur cycles [8]. In carbon contaminant-filled sediments, the environment usually quickly becomes anaerobic. As the environment becomes increasingly anoxic, Fe(III) becomes the most abundant and favourable electron acceptor for organic matter oxidation [8]. ''D. acetoxidans’'' ability to perform dissimilatory Fe(III) reduction can be coupled with the oxidation of organic contaminants, effectively removing them from the environment [8]. Recent studies are focused on the dissimilatory Fe(III) reduction aspect of ''D. acetoxidans'' rather than the sulphur reduction, since Fe(III) reduction signifies the production of electricity through the degradation of organic materials. This has been applied to the creation of [http://en.wikipedia.org/wiki/Microbial_fuel_cell microbial fuel cells], providing enough electricity to power basic electronic equipments [9].<br />
<br />
==References==<br />
[1] [http://www.ncbi.nlm.nih.gov/pubmed/21298162 Alves, A. S., Paquete, C. M., Fonseca, B. M., and Louro, R. O. “Exploration of the ‘cytochrome’ of ''Desulfuromonas acetoxidans'', a Marine Bacterium Capable of Powering Microbial Fuel Cells.” Metallomics, 2011, 3. p. 349–353. DOI: 10.1039/c0mt00084a]<br />
<br />
[2] [http://www.ncbi.nlm.nih.gov/pubmed/12119407 Assfalg, M., Bertini, I., Bruschi, M., Michel, C., and Turano, P. “The Metal Reductase Activity of Some Multiheme Cytochromes c: NMR Structural Characterization of the Reduction of Chromium(VI) to Chromium(III) by Cytochrome C7.” PNAS. 2002, DOI:10.1073.]<br />
<br />
[3] [http://www.ncbi.nlm.nih.gov/pubmed/9546165 Aubert, C., Lojou, E., Bianco, P., Rousset, M., Durand, M., Bruschi, M., and Dolla, A. “The Desulfuromonas acetoxidans Triheme Cytochrome C7 Produced in ''Desulfovibrio desulfuricans'' Retains Its Metal Reductase Activity.” Appl. Environ. Microbiol. 1998, 64(4):1308.]<br />
<br />
[4] [http://link.springer.com/article/10.1007%2FBF00689344?LI=true Biebl. H., Pfennig, N. “Growth Yields of Green Sulfur Bacteria in Mixed Cultures with Sulfur and Sulfate Reducing Bacteria.” Arch. Microbiol. 1978. 117, p. 9 -16.]<br />
<br />
[5] [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC361918/ Dumont, M. E., Cardillo, T. S., Hayes, M. K. and Sherman, F. “Role of cytochrome c heme lyase in mitochondrial import and accumulation of cytochrome c in Saccharomyces cerevisiae.” Mol Cell Biol. 1991 November; 11(11): 5487–5496. PMCID: PMC361918.]<br />
<br />
[6] [http://link.springer.com/article/10.1007%2FBF00428855?LI=true Gebhard , N. A., Thauer, R. K., Linder, D., Kaulfers, P., Pfennig, N. “Mechanism of acetate oxidation to CO2 with elemental sulfur in ''Desulfuromonas acetoxidans''.” Arch Microbiol (1985) 141:392-98.]<br />
<br />
[7] [http://www.ncbi.nlm.nih.gov/pubmed/21896772 Gillespie, J. J., Wattam, A. R., Cammer, S. A., Gabbard, J., Shukla, M. P., Dalay, O., Driscoll, T., Hix, D., Mane, S. P., Mao, C., Nordberg, E. K., Scott, M., Schulman, J. R., Snyder, E. E., Sullivan, D. E. Wang, C., Warren, A., Williams, K. P., Xue, T., Yoo, H. S., Zhang, C., Zhang, Y., Will, R., Kenyon, R.W. and Sobral B. W. (2011). “PATRIC: The Comprehensive Bacterial Bioinformatics Resource with a Focus on Human Pathogenic Species” Infect. Immun 79 (11): 4286-98. doi:10.1128/IAI.00207-11. PMID21896772.PMC3257917.]<br />
<br />
[8] [http://www.geobacter.org/publication-files/ASM_News_2002.pdf Lovley, D. R. “ Dissimilatory Metal Reduction: from Early Life to Bioremediation.” ASM News. 2002, 68(5). p. 231-37]<br />
<br />
[9] [http://www.geobacter.org/publication-files/Microbe_July_2006.pdf Lovley, D. R. “Microbial Energizers: Fuel Cells That Keep on Going.” Microbe. 2006, 1(6). p. 323-29.]<br />
<br />
[10] [http://www.ncbi.nlm.nih.gov/pubmed/1015937 Pfennig, N., and Biebl, H.. “''Desulfuromonas acetoxidans'' gen. nov. and sp. nov., a new anaerobic, sulfur-reducing, acetate-oxidizing bacterium.” Arch. Microbiol0., 1976, 110:3-12]<br />
<br />
[11] [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC202183/ Roden, E. R., Lovley, D. R. “Dissimilatory Fe(III) Reduction by the Marine Microorganism ''Desulfuromonas acetoxidans''.” Applied and Environmental Microbiology. 1993, 59(3). p. 734-42.]<br />
<br />
[12] [http://link.springer.com/article/10.1007%2FBF00248679?LI=true Warthmann, R., Cypionka, H., Pfennig, N. “Photoproduction of H2 from acetate by syntrophic cocultures of green sulfur bacteria and sulfur-reducing bacteria.” Arch Microbiol (1992), 157: 343-48.]<br />
<br />
[13] [http://www.ncbi.nlm.nih.gov/pubmed/16627667 Vandieken, V., Mußmann, B., Niemann, H., Jørgensen, B. B. “''Desulfuromonas svalbardensis'' sp. nov. and ''Desulfuromusa ferrireducens'' sp. nov., psychrophilic, Fe(III)-reducing bacteria isolated from Arctic sediments, Svalbard.” International Journal of Systematic and Evolutionary Microbiology (2006), 56: 1133–1139 DOI 10.1099.]</div>Jujublah311https://microbewiki.kenyon.edu/index.php?title=Desulfuromonas_acetoxidans&diff=78811Desulfuromonas acetoxidans2012-12-15T01:33:50Z<p>Jujublah311: </p>
<hr />
<div>==Classification==<br />
[[File:classification.jpeg|400px|thumb|right|FIGURE 1. Source: http://www.sciencedirect.com/science/article/pii/S0964830510001721 Phylogenetic tree based on 16s rRNA. Modified by adding a red box around desulfuromonas acetoxidans.]]<br />
===Higher order taxa===<br />
Kingdom: [http://en.wikipedia.org/wiki/Bacteria Bacteria]<br />
<br />
Phylum: [http://en.wikipedia.org/wiki/Proteobacteria Proteobacteria]<br />
<br />
Class: [http://en.wikipedia.org/wiki/Deltaproteobacteria Deltaproteobacteria]<br />
<br />
Order: [http://en.wikipedia.org/wiki/Desulfuromonadales Desulfuromonadales]<br />
<br />
Family: Desulfuromonadaceae<br />
<br />
Genus: [[Desulfuromonas]]<br />
[7]<br />
<br />
<br />
<br />
<br />
<br />
<br />
===Species===<br />
{|<br />
| height="10" bgcolor="#FFDF95" |<br />
'''NCBI: [http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=281689 Taxonomy]'''<br />
|}<br />
<br />
Species: ''Acetoxidans'' [7]<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
==Description and significance==<br />
''Desulfuromonas acetoxidans'' was first described in 1976 by N. Pfennig and H. Biebl [10]. The name has a Latin root, meaning “single-celled organism that reduces [http://en.wikipedia.org/wiki/Sulfur sulphur] (''Desulfuromonas'') and oxidizes [http://en.wikipedia.org/wiki/Acetate acetate] (''acetoxidans'')” [6, 10]. It was first described as a sulphur reducing bacteria capable of [http://en.wikipedia.org/wiki/Anaerobic_respiration anaerobically] reducing sulphur to [http://en.wikipedia.org/wiki/Sulfide sulphide] [10]. However, it was later discovered to also possess the ability to perform dissimilatory Fe(III) reduction coupled with the oxidation of organic compounds [11].<br />
<br />
''Desulfuromonas acetoxidans'' is a rod-shaped, [http://en.wikipedia.org/wiki/Gram-negative_bacteria Gram negative] bacterium that is predominantly found in marine sediments [10], though able to survive in fresh water environments [13]. The species is a strict anaerobe that uses a variety of electron donors, such as acetate, ethanol, propanol and butanol, to yield energy [10].<br />
<br />
''Desulfuromonas acetoxidans'' is part of the ''Desulfuromonas'' genus, which has a characteristic of being able to reduce sulphur through the conversion of elemental sulphur into sulphide [10]. ''D. acetoxidans'' is the first species described within the ''Desulfuromonas'' genus, and it is also the first marine microorganism ever described to support growth through Fe(III) or Mn(IV) reduction coupled to the oxidation of organic compounds [11]. <br />
<br />
As the first marine organism ever described to perform the oxidation of organic material coupled with reduction of Fe(III) or Mn(IV), ''D. acetoxidans'' has served as a model organism for the mechanism of Fe(III) or Mn(IV) oxidation of organic compounds [11]. <br />
<br />
<br />
==Genome structure==<br />
The genome sequence of ''D. acetoxidans'' was completed in 2007 with funding from the United states Department of Energy Joint Genome Institute [5]. The sequence is available [http://img.jgi.doe.gov/cgi-bin/w/main.cgi?section=TaxonDetail&taxon_oid=638341078 online] [7], though a formal description of the genome sequence has not been published in a peer-reviewed scientific journal. Its genome is 3.8Mb in length, and codes for 3234 putative genes [7]. A recent study has shown that the genome contains a very large number of genes coding for [http://en.wikipedia.org/wiki/Cytochrome_c c-type cytochromes] with multiple [http://en.wikipedia.org/wiki/Heme heme cofactors] [1]. Studies have found that the genome of ''D. acetoxidans'' codes for 47 possible multiheme cytochrome proteins [3]. A heme cofactor is a prosthetic group found on proteins that have diverse function [5]. In the case of c-type cytochrome, the heme cofactors function as both electron acceptors and electron donors [5]. The large percentage of genes coding for c-type cytochromes have been found to correlate with the ability of ''D. acetoxidans'' to reduce Fe(III) through the dissimilatory pathway [2]. In a study done by Aubert et al. (date, i.e. 2007), the genes that coded for the c-type cytochromes were inserted into the genome of the closely related [http://en.wikipedia.org/wiki/Desulfovibrio ''Desulfovibrio''] ''desulfuricans'', which is unable to reduce metals [3]. The transformed ''D. desulfuricans'' produced the c-type cytochromes and exhibited metal reductase activities [3]. This shows that the c-type cytochrome is vital in the reduction of Fe(III) or Mn(IV) in ''D. acetoxidans''. The mechanistic details concerning how these multiheme cytochromes work are still being studied, but C7 cytochrome is proposed to possess metal reductase activity [2].<br />
<br />
<br />
==Cell structure, metabolism and life cycle==<br />
[[File:Acetoxidanflagellum.jpeg|150px|thumb|left|FIGURE 2: Electron Microscopy of Desulfuromonas acetoxidans that clearly shows the flagellum at the lateral side of cell body. Source: http://garciajeanlouis9051.perso.neuf.fr/aaBXIII4_O4_5.html]]<br />
[[File:Cellwall.gif|375px|thumb|right|FIGURE 3. A figure visualizing the differences between Gram positive and Gram negative cell walls. Source: http://water.me.vccs.edu/courses/env108/Lesson5_print.htm]]<br />
<br />
<br />
<br />
''D.acetoxidans'' has the following characteristics: i) dimensions of 0.4 - 0.7μm in width and 1 - 4μm in length, ii) a single [http://en.wikipedia.org/wiki/Flagellum flagellum] on the lateral side of the rod-shaped bacteria and even though it possesses a flagellum, most strains were not motile (figure 2.) [10]. Its cell envelope resembles those of other gram negative bacteria, with an outer membrane separated from the cytoplasmic membrane by a thin layer of [http://en.wikipedia.org/wiki/Peptidoglycan peptidoglycan] (figure 3.) [10]. ''D. acetoxidans'' have been found to be non-sporulating, free living bacterium that divides via [http://en.wikipedia.org/wiki/Fission_(biology)#Binary_fission_of_prokaryotes binary fission] [10].<br />
<br />
<br />
<br />
''D. acetoxidans'' possesses a complex metabolism, and energy for [http://en.wikipedia.org/wiki/Metabolism metabolism] comes from a variety of redox reactions. They are [http://en.wikipedia.org/wiki/Chemoorganotroph chemoorganotrophs] that respire anaerobically, using acetate, ethanol or propanol as carbon sources and electron donors in the presence of ~0.2mM bicarbonate [10]. These organic carbon sources are completely oxidized to CO2 [6, 10]. When ''D. acetoxidans'' is reducing sulphuric compounds, either elemental sulphur or disulfide bonds within compounds such as malate or fumarate serve as electron acceptors and are reduced to H2S and sulfhydryl-groups, respectively[10]. <br />
<br />
<br />
<br />
''D. acetoxidans'', when present in different media, has different cytochromes that are present as the dominant type, but there is one type (C7 cytochrome) that is always present, suggesting that this cytochrome plays a key role in metabolism [2]. Studies have also shown that cytochrome C7 plays a role as an electron-transfer protein in the sulphur reduction, as well as in reduction of Fe(III) and Mn(IV) [2]. <br />
<br />
<br />
<br />
==Ecology==<br />
''Desulfuromonas acetoxidans'' is found primarily in anoxic marine sediment, and rarely found in freshwater sediments [13]. It is able to grow in a pH-range of 6.5 to 8.5, but its optimum pH between 7.2 and 7.5 [10]. ''D. acetoxidans'' has an optimum growth temperature of ~30。C, but it can grow in temperature ranging from 25。C to 35。C [10]. In some environments, ''D. acetoxidans'' grows syntrophically with green sulphur bacteria [4, 8]. Their relationship is mutualistic in that the [http://en.wikipedia.org/wiki/Green_sulfur_bacteria green sulphur bacteria] presents dissolved and readily metabolizable form of sulphur which is used by ''D. acetoxidans'' (refer to figure). The sulphur is oxidized by ''D. acetoxidans'' to sulphur, which the green sulphur bacteria can use, this is shown schematically by Figure 4 [4, 12].<br />
The species has biogeochemical significance as it plays a role in the carbon and sulphur cycles [8]. In carbon contaminant-filled sediments, the environment usually quickly becomes anaerobic. As the environment becomes increasingly anoxic, Fe(III) becomes the most abundant and favourable electron acceptor for organic matter oxidation [8]. ''D. acetoxidans’'' ability to perform dissimilatory Fe(III) reduction can be coupled with the oxidation of organic contaminants, effectively removing them from the environment [8]. Recent studies are focused on the dissimilatory Fe(III) reduction aspect of ''D. acetoxidans'' rather than the sulphur reduction, since Fe(III) reduction signifies the production of electricity through the degradation of organic materials. This has been applied to the creation of [http://en.wikipedia.org/wiki/Microbial_fuel_cell microbial fuel cells], providing enough electricity to power basic electronic equipments [9].<br />
<br />
==References==<br />
[1] [http://www.ncbi.nlm.nih.gov/pubmed/21298162 Alves, A. S., Paquete, C. M., Fonseca, B. M., and Louro, R. O. “Exploration of the ‘cytochrome’ of ''Desulfuromonas acetoxidans'', a Marine Bacterium Capable of Powering Microbial Fuel Cells.” Metallomics, 2011, 3. p. 349–353. DOI: 10.1039/c0mt00084a]<br />
<br />
[2] [http://www.ncbi.nlm.nih.gov/pubmed/12119407 Assfalg, M., Bertini, I., Bruschi, M., Michel, C., and Turano, P. “The Metal Reductase Activity of Some Multiheme Cytochromes c: NMR Structural Characterization of the Reduction of Chromium(VI) to Chromium(III) by Cytochrome C7.” PNAS. 2002, DOI:10.1073.]<br />
<br />
[3] [http://www.ncbi.nlm.nih.gov/pubmed/9546165 Aubert, C., Lojou, E., Bianco, P., Rousset, M., Durand, M., Bruschi, M., and Dolla, A. “The Desulfuromonas acetoxidans Triheme Cytochrome C7 Produced in ''Desulfovibrio desulfuricans'' Retains Its Metal Reductase Activity.” Appl. Environ. Microbiol. 1998, 64(4):1308.]<br />
<br />
[4] [http://link.springer.com/article/10.1007%2FBF00689344?LI=true Biebl. H., Pfennig, N. “Growth Yields of Green Sulfur Bacteria in Mixed Cultures with Sulfur and Sulfate Reducing Bacteria.” Arch. Microbiol. 1978. 117, p. 9 -16.]<br />
<br />
[5] [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC361918/ Dumont, M. E., Cardillo, T. S., Hayes, M. K. and Sherman, F. “Role of cytochrome c heme lyase in mitochondrial import and accumulation of cytochrome c in Saccharomyces cerevisiae.” Mol Cell Biol. 1991 November; 11(11): 5487–5496. PMCID: PMC361918.]<br />
<br />
[6] [http://link.springer.com/article/10.1007%2FBF00428855?LI=true Gebhard , N. A., Thauer, R. K., Linder, D., Kaulfers, P., Pfennig, N. “Mechanism of acetate oxidation to CO2 with elemental sulfur in ''Desulfuromonas acetoxidans''.” Arch Microbiol (1985) 141:392-98.]<br />
<br />
[7] [http://www.ncbi.nlm.nih.gov/pubmed/21896772 Gillespie, J. J., Wattam, A. R., Cammer, S. A., Gabbard, J., Shukla, M. P., Dalay, O., Driscoll, T., Hix, D., Mane, S. P., Mao, C., Nordberg, E. K., Scott, M., Schulman, J. R., Snyder, E. E., Sullivan, D. E. Wang, C., Warren, A., Williams, K. P., Xue, T., Yoo, H. S., Zhang, C., Zhang, Y., Will, R., Kenyon, R.W. and Sobral B. W. (2011). “PATRIC: The Comprehensive Bacterial Bioinformatics Resource with a Focus on Human Pathogenic Species” Infect. Immun 79 (11): 4286-98. doi:10.1128/IAI.00207-11. PMID21896772.PMC3257917.]<br />
<br />
[8] [http://www.geobacter.org/publication-files/ASM_News_2002.pdf Lovley, D. R. “ Dissimilatory Metal Reduction: from Early Life to Bioremediation.” ASM News. 2002, 68(5). p. 231-37]<br />
<br />
[9] [http://www.geobacter.org/publication-files/Microbe_July_2006.pdf Lovley, D. R. “Microbial Energizers: Fuel Cells That Keep on Going.” Microbe. 2006, 1(6). p. 323-29.]<br />
<br />
[10] [http://www.ncbi.nlm.nih.gov/pubmed/1015937 Pfennig, N., and Biebl, H.. “''Desulfuromonas acetoxidans'' gen. nov. and sp. nov., a new anaerobic, sulfur-reducing, acetate-oxidizing bacterium.” Arch. Microbiol0., 1976, 110:3-12]<br />
<br />
[11] [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC202183/ Roden, E. R., Lovley, D. R. “Dissimilatory Fe(III) Reduction by the Marine Microorganism ''Desulfuromonas acetoxidans''.” Applied and Environmental Microbiology. 1993, 59(3). p. 734-42.]<br />
<br />
[12] [http://link.springer.com/article/10.1007%2FBF00248679?LI=true Warthmann, R., Cypionka, H., Pfennig, N. “Photoproduction of H2 from acetate by syntrophic cocultures of green sulfur bacteria and sulfur-reducing bacteria.” Arch Microbiol (1992), 157: 343-48.]<br />
<br />
[13] [http://www.ncbi.nlm.nih.gov/pubmed/16627667 Vandieken, V., Mußmann, B., Niemann, H., Jørgensen, B. B. “''Desulfuromonas svalbardensis'' sp. nov. and ''Desulfuromusa ferrireducens'' sp. nov., psychrophilic, Fe(III)-reducing bacteria isolated from Arctic sediments, Svalbard.” International Journal of Systematic and Evolutionary Microbiology (2006), 56: 1133–1139 DOI 10.1099.]</div>Jujublah311https://microbewiki.kenyon.edu/index.php?title=Desulfuromonas_acetoxidans&diff=78809Desulfuromonas acetoxidans2012-12-15T01:26:50Z<p>Jujublah311: </p>
<hr />
<div>==Classification==<br />
[[File:classification.jpeg|400px|thumb|right|FIGURE 1. Source: http://www.sciencedirect.com/science/article/pii/S0964830510001721 Phylogenetic tree based on 16s rRNA. Modified by adding a red box around desulfuromonas acetoxidans.]]<br />
===Higher order taxa===<br />
Kingdom: [http://en.wikipedia.org/wiki/Bacteria Bacteria]<br />
<br />
Phylum: [http://en.wikipedia.org/wiki/Proteobacteria Proteobacteria]<br />
<br />
Class: [http://en.wikipedia.org/wiki/Deltaproteobacteria Deltaproteobacteria]<br />
<br />
Order: [http://en.wikipedia.org/wiki/Desulfuromonadales Desulfuromonadales]<br />
<br />
Family: Desulfuromonadaceae<br />
<br />
Genus: [[Desulfuromonas]]<br />
[7]<br />
<br />
<br />
<br />
<br />
<br />
<br />
===Species===<br />
{|<br />
| height="10" bgcolor="#FFDF95" |<br />
'''NCBI: [http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=281689 Taxonomy]'''<br />
|}<br />
<br />
Species: ''Acetoxidans'' [7]<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
==Description and significance==<br />
''Desulfuromonas acetoxidans'' was first described in 1976 by N. Pfennig and H. Biebl [10]. The name has a Latin root, meaning “single-celled organism that reduces [http://en.wikipedia.org/wiki/Sulfur sulphur] (''Desulfuromonas'') and oxidizes [http://en.wikipedia.org/wiki/Acetate acetate] (''acetoxidans'')” [6, 10]. It was first described as a sulphur reducing bacteria capable of [http://en.wikipedia.org/wiki/Anaerobic_respiration anaerobically] reducing sulphur to [http://en.wikipedia.org/wiki/Sulfide sulphide] [10]. However, it was later discovered to also possess the ability to perform dissimilatory Fe(III) reduction coupled with the oxidation of organic compounds [11].<br />
<br />
''Desulfuromonas acetoxidans'' is a rod-shaped, [http://en.wikipedia.org/wiki/Gram-negative_bacteria Gram negative] bacterium that is predominantly found in marine sediments [10], though able to survive in fresh water environments [13]. The species is a strict anaerobe that uses a variety of electron donors, such as acetate, ethanol, propanol and butanol, to yield energy [10].<br />
<br />
''Desulfuromonas acetoxidans'' is part of the ''Desulfuromonas'' genus, which has a characteristic of being able to reduce sulphur through the conversion of elemental sulphur into sulphide [10]. ''D. acetoxidans'' is the first species described within the ''Desulfuromonas'' genus, and it is also the first marine microorganism ever described to support growth through Fe(III) or Mn(IV) reduction coupled to the oxidation of organic compounds [11]. <br />
<br />
As the first marine organism ever described to perform the oxidation of organic material coupled with reduction of Fe(III) or Mn(IV), ''D. acetoxidans'' has served as a model organism for the mechanism of Fe(III) or Mn(IV) oxidation of organic compounds [11]. <br />
<br />
<br />
==Genome structure==<br />
The genome sequence of ''D. acetoxidans'' was completed in 2007 with funding from the United states Department of Energy Joint Genome Institute [5]. The sequence is available [http://img.jgi.doe.gov/cgi-bin/w/main.cgi?section=TaxonDetail&taxon_oid=638341078 online] [7], though a formal description of the genome sequence has not been published in a peer-reviewed scientific journal. Its genome is 3.8Mb in length, and codes for 3234 putative genes [7]. A recent study has shown that the genome contains a very large number of genes coding for [http://en.wikipedia.org/wiki/Cytochrome_c c-type cytochromes] with multiple [http://en.wikipedia.org/wiki/Heme heme cofactors] [1]. Studies have found that the genome of ''D. acetoxidans'' codes for 47 possible multiheme cytochrome proteins [3]. A heme cofactor is a prosthetic group found on proteins that have diverse function [5]. In the case of c-type cytochrome, the heme cofactors function as both electron acceptors and electron donors [5]. The large percentage of genes coding for c-type cytochromes have been found to correlate with the ability of ''D. acetoxidans'' to reduce Fe(III) through the dissimilatory pathway [2]. In a study done by Aubert et al. (date, i.e. 2007), the genes that coded for the c-type cytochromes were inserted into the genome of the closely related [http://en.wikipedia.org/wiki/Desulfovibrio ''Desulfovibrio''] ''desulfuricans'', which is unable to reduce metals [3]. The transformed ''D. desulfuricans'' produced the c-type cytochromes and exhibited metal reductase activities [3]. This shows that the c-type cytochrome is vital in the reduction of Fe(III) or Mn(IV) in ''D. acetoxidans''. The mechanistic details concerning how these multiheme cytochromes work are still being studied, but C7 cytochrome is proposed to possess metal reductase activity [2].<br />
<br />
<br />
==Cell structure, metabolism and life cycle==<br />
[[File:Acetoxidanflagellum.jpeg|200px|thumb|right|FIGURE 2: Electron Microscopy of Desulfuromonas acetoxidans that clearly shows the flagellum at the lateral side of cell body. Source: http://garciajeanlouis9051.perso.neuf.fr/aaBXIII4_O4_5.html]]<br />
<br />
''D.acetoxidans'' has the following characteristics: i) dimensions of 0.4 - 0.7μm in width and 1 - 4μm in length, ii) a single [http://en.wikipedia.org/wiki/Flagellum flagellum] on the lateral side of the rod-shaped bacteria and even though it possesses a flagellum, most strains were not motile (figure 2.) [10]. Its cell envelope resembles those of other gram negative bacteria, with an outer membrane separated from the cytoplasmic membrane by a thin layer of [http://en.wikipedia.org/wiki/Peptidoglycan peptidoglycan] (figure 3.) [10]. ''D. acetoxidans'' have been found to be non-sporulating, free living bacterium that divides via [http://en.wikipedia.org/wiki/Fission_(biology)#Binary_fission_of_prokaryotes binary fission] [10].<br />
<br />
''D. acetoxidans'' possesses a complex metabolism, and energy for [http://en.wikipedia.org/wiki/Metabolism metabolism] comes from a variety of redox reactions. They are [http://en.wikipedia.org/wiki/Chemoorganotroph chemoorganotrophs] that respire anaerobically, using acetate, ethanol or propanol as carbon sources and electron donors in the presence of ~0.2mM bicarbonate [10]. These organic carbon sources are completely oxidized to CO2 [6, 10]. When ''D. acetoxidans'' is reducing sulphuric compounds, either elemental sulphur or disulfide bonds within compounds such as malate or fumarate serve as electron acceptors and are reduced to H2S and sulfhydryl-groups, respectively[10]. <br />
<br />
''D. acetoxidans'', when present in different media, has different cytochromes that are present as the dominant type, but there is one type (C7 cytochrome) that is always present, suggesting that this cytochrome plays a key role in metabolism [2]. Studies have also shown that cytochrome C7 plays a role as an electron-transfer protein in the sulphur reduction, as well as in reduction of Fe(III) and Mn(IV) [2]. <br />
<br />
==Ecology==<br />
''Desulfuromonas acetoxidans'' is found primarily in anoxic marine sediment, and rarely found in freshwater sediments [13]. It is able to grow in a pH-range of 6.5 to 8.5, but its optimum pH between 7.2 and 7.5 [10]. ''D. acetoxidans'' has an optimum growth temperature of ~30。C, but it can grow in temperature ranging from 25。C to 35。C [10]. In some environments, ''D. acetoxidans'' grows syntrophically with green sulphur bacteria [4, 8]. Their relationship is mutualistic in that the [http://en.wikipedia.org/wiki/Green_sulfur_bacteria green sulphur bacteria] presents dissolved and readily metabolizable form of sulphur which is used by ''D. acetoxidans'' (refer to figure). The sulphur is oxidized by ''D. acetoxidans'' to sulphur, which the green sulphur bacteria can use [4, 12].<br />
The species has biogeochemical significance as it plays a role in the carbon and sulphur cycles [8]. In carbon contaminant-filled sediments, the environment usually quickly becomes anaerobic. As the environment becomes increasingly anoxic, Fe(III) becomes the most abundant and favourable electron acceptor for organic matter oxidation [8]. ''D. acetoxidans’'' ability to perform dissimilatory Fe(III) reduction can be coupled with the oxidation of organic contaminants, effectively removing them from the environment [8]. Recent studies are focused on the dissimilatory Fe(III) reduction aspect of ''D. acetoxidans'' rather than the sulphur reduction, since Fe(III) reduction signifies the production of electricity through the degradation of organic materials. This has been applied to the creation of [http://en.wikipedia.org/wiki/Microbial_fuel_cell microbial fuel cells], providing enough electricity to power basic electronic equipments [9].<br />
<br />
==References==<br />
[1] [http://www.ncbi.nlm.nih.gov/pubmed/21298162 Alves, A. S., Paquete, C. M., Fonseca, B. M., and Louro, R. O. “Exploration of the ‘cytochrome’ of ''Desulfuromonas acetoxidans'', a Marine Bacterium Capable of Powering Microbial Fuel Cells.” Metallomics, 2011, 3. p. 349–353. DOI: 10.1039/c0mt00084a]<br />
<br />
[2] [http://www.ncbi.nlm.nih.gov/pubmed/12119407 Assfalg, M., Bertini, I., Bruschi, M., Michel, C., and Turano, P. “The Metal Reductase Activity of Some Multiheme Cytochromes c: NMR Structural Characterization of the Reduction of Chromium(VI) to Chromium(III) by Cytochrome C7.” PNAS. 2002, DOI:10.1073.]<br />
<br />
[3] [http://www.ncbi.nlm.nih.gov/pubmed/9546165 Aubert, C., Lojou, E., Bianco, P., Rousset, M., Durand, M., Bruschi, M., and Dolla, A. “The Desulfuromonas acetoxidans Triheme Cytochrome C7 Produced in ''Desulfovibrio desulfuricans'' Retains Its Metal Reductase Activity.” Appl. Environ. Microbiol. 1998, 64(4):1308.]<br />
<br />
[4] [http://link.springer.com/article/10.1007%2FBF00689344?LI=true Biebl. H., Pfennig, N. “Growth Yields of Green Sulfur Bacteria in Mixed Cultures with Sulfur and Sulfate Reducing Bacteria.” Arch. Microbiol. 1978. 117, p. 9 -16.]<br />
<br />
[5] [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC361918/ Dumont, M. E., Cardillo, T. S., Hayes, M. K. and Sherman, F. “Role of cytochrome c heme lyase in mitochondrial import and accumulation of cytochrome c in Saccharomyces cerevisiae.” Mol Cell Biol. 1991 November; 11(11): 5487–5496. PMCID: PMC361918.]<br />
<br />
[6] [http://link.springer.com/article/10.1007%2FBF00428855?LI=true Gebhard , N. A., Thauer, R. K., Linder, D., Kaulfers, P., Pfennig, N. “Mechanism of acetate oxidation to CO2 with elemental sulfur in ''Desulfuromonas acetoxidans''.” Arch Microbiol (1985) 141:392-98.]<br />
<br />
[7] [http://www.ncbi.nlm.nih.gov/pubmed/21896772 Gillespie, J. J., Wattam, A. R., Cammer, S. A., Gabbard, J., Shukla, M. P., Dalay, O., Driscoll, T., Hix, D., Mane, S. P., Mao, C., Nordberg, E. K., Scott, M., Schulman, J. R., Snyder, E. E., Sullivan, D. E. Wang, C., Warren, A., Williams, K. P., Xue, T., Yoo, H. S., Zhang, C., Zhang, Y., Will, R., Kenyon, R.W. and Sobral B. W. (2011). “PATRIC: The Comprehensive Bacterial Bioinformatics Resource with a Focus on Human Pathogenic Species” Infect. Immun 79 (11): 4286-98. doi:10.1128/IAI.00207-11. PMID21896772.PMC3257917.]<br />
<br />
[8] [http://www.geobacter.org/publication-files/ASM_News_2002.pdf Lovley, D. R. “ Dissimilatory Metal Reduction: from Early Life to Bioremediation.” ASM News. 2002, 68(5). p. 231-37]<br />
<br />
[9] [http://www.geobacter.org/publication-files/Microbe_July_2006.pdf Lovley, D. R. “Microbial Energizers: Fuel Cells That Keep on Going.” Microbe. 2006, 1(6). p. 323-29.]<br />
<br />
[10] [http://www.ncbi.nlm.nih.gov/pubmed/1015937 Pfennig, N., and Biebl, H.. “''Desulfuromonas acetoxidans'' gen. nov. and sp. nov., a new anaerobic, sulfur-reducing, acetate-oxidizing bacterium.” Arch. Microbiol0., 1976, 110:3-12]<br />
<br />
[11] [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC202183/ Roden, E. R., Lovley, D. R. “Dissimilatory Fe(III) Reduction by the Marine Microorganism ''Desulfuromonas acetoxidans''.” Applied and Environmental Microbiology. 1993, 59(3). p. 734-42.]<br />
<br />
[12] [http://link.springer.com/article/10.1007%2FBF00248679?LI=true Warthmann, R., Cypionka, H., Pfennig, N. “Photoproduction of H2 from acetate by syntrophic cocultures of green sulfur bacteria and sulfur-reducing bacteria.” Arch Microbiol (1992), 157: 343-48.]<br />
<br />
[13] [http://www.ncbi.nlm.nih.gov/pubmed/16627667 Vandieken, V., Mußmann, B., Niemann, H., Jørgensen, B. B. “''Desulfuromonas svalbardensis'' sp. nov. and ''Desulfuromusa ferrireducens'' sp. nov., psychrophilic, Fe(III)-reducing bacteria isolated from Arctic sediments, Svalbard.” International Journal of Systematic and Evolutionary Microbiology (2006), 56: 1133–1139 DOI 10.1099.]</div>Jujublah311https://microbewiki.kenyon.edu/index.php?title=Desulfuromonas_acetoxidans&diff=78808Desulfuromonas acetoxidans2012-12-15T01:21:00Z<p>Jujublah311: </p>
<hr />
<div>==Classification==<br />
[[File:classification.jpeg|400px|thumb|right|FIGURE 1. Source: http://garciajeanlouis9051.perso.neuf.fr/aaBXIII4_O4_5.html Electron Microscopy of Desulfuromonas acetoxidans that clearly shows the flagellum at the lateral side of cell body ]]<br />
===Higher order taxa===<br />
Kingdom: [http://en.wikipedia.org/wiki/Bacteria Bacteria]<br />
<br />
Phylum: [http://en.wikipedia.org/wiki/Proteobacteria Proteobacteria]<br />
<br />
Class: [http://en.wikipedia.org/wiki/Deltaproteobacteria Deltaproteobacteria]<br />
<br />
Order: [http://en.wikipedia.org/wiki/Desulfuromonadales Desulfuromonadales]<br />
<br />
Family: Desulfuromonadaceae<br />
<br />
Genus: [[Desulfuromonas]]<br />
[7]<br />
<br />
<br />
<br />
<br />
<br />
<br />
===Species===<br />
{|<br />
| height="10" bgcolor="#FFDF95" |<br />
'''NCBI: [http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=281689 Taxonomy]'''<br />
|}<br />
<br />
Species: ''Acetoxidans'' [7]<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
==Description and significance==<br />
''Desulfuromonas acetoxidans'' was first described in 1976 by N. Pfennig and H. Biebl [10]. The name has a Latin root, meaning “single-celled organism that reduces [http://en.wikipedia.org/wiki/Sulfur sulphur] (''Desulfuromonas'') and oxidizes [http://en.wikipedia.org/wiki/Acetate acetate] (''acetoxidans'')” [6, 10]. It was first described as a sulphur reducing bacteria capable of [http://en.wikipedia.org/wiki/Anaerobic_respiration anaerobically] reducing sulphur to [http://en.wikipedia.org/wiki/Sulfide sulphide] [10]. However, it was later discovered to also possess the ability to perform dissimilatory Fe(III) reduction coupled with the oxidation of organic compounds [11].<br />
<br />
''Desulfuromonas acetoxidans'' is a rod-shaped, [http://en.wikipedia.org/wiki/Gram-negative_bacteria Gram negative] bacterium that is predominantly found in marine sediments [10], though able to survive in fresh water environments [13]. The species is a strict anaerobe that uses a variety of electron donors, such as acetate, ethanol, propanol and butanol, to yield energy [10].<br />
<br />
''Desulfuromonas acetoxidans'' is part of the ''Desulfuromonas'' genus, which has a characteristic of being able to reduce sulphur through the conversion of elemental sulphur into sulphide [10]. ''D. acetoxidans'' is the first species described within the ''Desulfuromonas'' genus, and it is also the first marine microorganism ever described to support growth through Fe(III) or Mn(IV) reduction coupled to the oxidation of organic compounds [11]. <br />
<br />
As the first marine organism ever described to perform the oxidation of organic material coupled with reduction of Fe(III) or Mn(IV), ''D. acetoxidans'' has served as a model organism for the mechanism of Fe(III) or Mn(IV) oxidation of organic compounds [11]. <br />
<br />
<br />
==Genome structure==<br />
The genome sequence of ''D. acetoxidans'' was completed in 2007 with funding from the United states Department of Energy Joint Genome Institute [5]. The sequence is available [http://img.jgi.doe.gov/cgi-bin/w/main.cgi?section=TaxonDetail&taxon_oid=638341078 online] [7], though a formal description of the genome sequence has not been published in a peer-reviewed scientific journal. Its genome is 3.8Mb in length, and codes for 3234 putative genes [7]. A recent study has shown that the genome contains a very large number of genes coding for [http://en.wikipedia.org/wiki/Cytochrome_c c-type cytochromes] with multiple [http://en.wikipedia.org/wiki/Heme heme cofactors] [1]. Studies have found that the genome of ''D. acetoxidans'' codes for 47 possible multiheme cytochrome proteins [3]. A heme cofactor is a prosthetic group found on proteins that have diverse function [5]. In the case of c-type cytochrome, the heme cofactors function as both electron acceptors and electron donors [5]. The large percentage of genes coding for c-type cytochromes have been found to correlate with the ability of ''D. acetoxidans'' to reduce Fe(III) through the dissimilatory pathway [2]. In a study done by Aubert et al. (date, i.e. 2007), the genes that coded for the c-type cytochromes were inserted into the genome of the closely related [http://en.wikipedia.org/wiki/Desulfovibrio ''Desulfovibrio''] ''desulfuricans'', which is unable to reduce metals [3]. The transformed ''D. desulfuricans'' produced the c-type cytochromes and exhibited metal reductase activities [3]. This shows that the c-type cytochrome is vital in the reduction of Fe(III) or Mn(IV) in ''D. acetoxidans''. The mechanistic details concerning how these multiheme cytochromes work are still being studied, but C7 cytochrome is proposed to possess metal reductase activity [2].<br />
<br />
<br />
==Cell structure, metabolism and life cycle==<br />
''D.acetoxidans'' has the following characteristics: i) dimensions of 0.4 - 0.7μm in width and 1 - 4μm in length, ii) a single [http://en.wikipedia.org/wiki/Flagellum flagellum] on the lateral side of the rod-shaped bacteria and even though it possesses a flagellum, most strains were not motile [10]. Its cell envelope resembles those of other gram negative bacteria, with an outer membrane separated from the cytoplasmic membrane by a thin layer of [http://en.wikipedia.org/wiki/Peptidoglycan peptidoglycan] [10]. ''D. acetoxidans'' have been found to be non-sporulating, free living bacterium that divides via [http://en.wikipedia.org/wiki/Fission_(biology)#Binary_fission_of_prokaryotes binary fission] [10].<br />
<br />
''D. acetoxidans'' possesses a complex metabolism, and energy for [http://en.wikipedia.org/wiki/Metabolism metabolism] comes from a variety of redox reactions. They are [http://en.wikipedia.org/wiki/Chemoorganotroph chemoorganotrophs] that respire anaerobically, using acetate, ethanol or propanol as carbon sources and electron donors in the presence of ~0.2mM bicarbonate [10]. These organic carbon sources are completely oxidized to CO2 [6, 10]. When ''D. acetoxidans'' is reducing sulphuric compounds, either elemental sulphur or disulfide bonds within compounds such as malate or fumarate serve as electron acceptors and are reduced to H2S and sulfhydryl-groups, respectively[10]. <br />
<br />
''D. acetoxidans'', when present in different media, has different cytochromes that are present as the dominant type, but there is one type (C7 cytochrome) that is always present, suggesting that this cytochrome plays a key role in metabolism [2]. Studies have also shown that cytochrome C7 plays a role as an electron-transfer protein in the sulphur reduction, as well as in reduction of Fe(III) and Mn(IV) [2]. <br />
<br />
==Ecology==<br />
''Desulfuromonas acetoxidans'' is found primarily in anoxic marine sediment, and rarely found in freshwater sediments [13]. It is able to grow in a pH-range of 6.5 to 8.5, but its optimum pH between 7.2 and 7.5 [10]. ''D. acetoxidans'' has an optimum growth temperature of ~30。C, but it can grow in temperature ranging from 25。C to 35。C [10]. In some environments, ''D. acetoxidans'' grows syntrophically with green sulphur bacteria [4, 8]. Their relationship is mutualistic in that the [http://en.wikipedia.org/wiki/Green_sulfur_bacteria green sulphur bacteria] presents dissolved and readily metabolizable form of sulphur which is used by ''D. acetoxidans'' (refer to figure). The sulphur is oxidized by ''D. acetoxidans'' to sulphur, which the green sulphur bacteria can use [4, 12].<br />
The species has biogeochemical significance as it plays a role in the carbon and sulphur cycles [8]. In carbon contaminant-filled sediments, the environment usually quickly becomes anaerobic. As the environment becomes increasingly anoxic, Fe(III) becomes the most abundant and favourable electron acceptor for organic matter oxidation [8]. ''D. acetoxidans’'' ability to perform dissimilatory Fe(III) reduction can be coupled with the oxidation of organic contaminants, effectively removing them from the environment [8]. Recent studies are focused on the dissimilatory Fe(III) reduction aspect of ''D. acetoxidans'' rather than the sulphur reduction, since Fe(III) reduction signifies the production of electricity through the degradation of organic materials. This has been applied to the creation of [http://en.wikipedia.org/wiki/Microbial_fuel_cell microbial fuel cells], providing enough electricity to power basic electronic equipments [9].<br />
<br />
==References==<br />
[1] [http://www.ncbi.nlm.nih.gov/pubmed/21298162 Alves, A. S., Paquete, C. M., Fonseca, B. M., and Louro, R. O. “Exploration of the ‘cytochrome’ of ''Desulfuromonas acetoxidans'', a Marine Bacterium Capable of Powering Microbial Fuel Cells.” Metallomics, 2011, 3. p. 349–353. DOI: 10.1039/c0mt00084a]<br />
<br />
[2] [http://www.ncbi.nlm.nih.gov/pubmed/12119407 Assfalg, M., Bertini, I., Bruschi, M., Michel, C., and Turano, P. “The Metal Reductase Activity of Some Multiheme Cytochromes c: NMR Structural Characterization of the Reduction of Chromium(VI) to Chromium(III) by Cytochrome C7.” PNAS. 2002, DOI:10.1073.]<br />
<br />
[3] [http://www.ncbi.nlm.nih.gov/pubmed/9546165 Aubert, C., Lojou, E., Bianco, P., Rousset, M., Durand, M., Bruschi, M., and Dolla, A. “The Desulfuromonas acetoxidans Triheme Cytochrome C7 Produced in ''Desulfovibrio desulfuricans'' Retains Its Metal Reductase Activity.” Appl. Environ. Microbiol. 1998, 64(4):1308.]<br />
<br />
[4] [http://link.springer.com/article/10.1007%2FBF00689344?LI=true Biebl. H., Pfennig, N. “Growth Yields of Green Sulfur Bacteria in Mixed Cultures with Sulfur and Sulfate Reducing Bacteria.” Arch. Microbiol. 1978. 117, p. 9 -16.]<br />
<br />
[5] [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC361918/ Dumont, M. E., Cardillo, T. S., Hayes, M. K. and Sherman, F. “Role of cytochrome c heme lyase in mitochondrial import and accumulation of cytochrome c in Saccharomyces cerevisiae.” Mol Cell Biol. 1991 November; 11(11): 5487–5496. PMCID: PMC361918.]<br />
<br />
[6] [http://link.springer.com/article/10.1007%2FBF00428855?LI=true Gebhard , N. A., Thauer, R. K., Linder, D., Kaulfers, P., Pfennig, N. “Mechanism of acetate oxidation to CO2 with elemental sulfur in ''Desulfuromonas acetoxidans''.” Arch Microbiol (1985) 141:392-98.]<br />
<br />
[7] [http://www.ncbi.nlm.nih.gov/pubmed/21896772 Gillespie, J. J., Wattam, A. R., Cammer, S. A., Gabbard, J., Shukla, M. P., Dalay, O., Driscoll, T., Hix, D., Mane, S. P., Mao, C., Nordberg, E. K., Scott, M., Schulman, J. R., Snyder, E. E., Sullivan, D. E. Wang, C., Warren, A., Williams, K. P., Xue, T., Yoo, H. S., Zhang, C., Zhang, Y., Will, R., Kenyon, R.W. and Sobral B. W. (2011). “PATRIC: The Comprehensive Bacterial Bioinformatics Resource with a Focus on Human Pathogenic Species” Infect. Immun 79 (11): 4286-98. doi:10.1128/IAI.00207-11. PMID21896772.PMC3257917.]<br />
<br />
[8] [http://www.geobacter.org/publication-files/ASM_News_2002.pdf Lovley, D. R. “ Dissimilatory Metal Reduction: from Early Life to Bioremediation.” ASM News. 2002, 68(5). p. 231-37]<br />
<br />
[9] [http://www.geobacter.org/publication-files/Microbe_July_2006.pdf Lovley, D. R. “Microbial Energizers: Fuel Cells That Keep on Going.” Microbe. 2006, 1(6). p. 323-29.]<br />
<br />
[10] [http://www.ncbi.nlm.nih.gov/pubmed/1015937 Pfennig, N., and Biebl, H.. “''Desulfuromonas acetoxidans'' gen. nov. and sp. nov., a new anaerobic, sulfur-reducing, acetate-oxidizing bacterium.” Arch. Microbiol0., 1976, 110:3-12]<br />
<br />
[11] [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC202183/ Roden, E. R., Lovley, D. R. “Dissimilatory Fe(III) Reduction by the Marine Microorganism ''Desulfuromonas acetoxidans''.” Applied and Environmental Microbiology. 1993, 59(3). p. 734-42.]<br />
<br />
[12] [http://link.springer.com/article/10.1007%2FBF00248679?LI=true Warthmann, R., Cypionka, H., Pfennig, N. “Photoproduction of H2 from acetate by syntrophic cocultures of green sulfur bacteria and sulfur-reducing bacteria.” Arch Microbiol (1992), 157: 343-48.]<br />
<br />
[13] [http://www.ncbi.nlm.nih.gov/pubmed/16627667 Vandieken, V., Mußmann, B., Niemann, H., Jørgensen, B. B. “''Desulfuromonas svalbardensis'' sp. nov. and ''Desulfuromusa ferrireducens'' sp. nov., psychrophilic, Fe(III)-reducing bacteria isolated from Arctic sediments, Svalbard.” International Journal of Systematic and Evolutionary Microbiology (2006), 56: 1133–1139 DOI 10.1099.]</div>Jujublah311https://microbewiki.kenyon.edu/index.php?title=File:Acetoxidanflagellum.jpeg&diff=78805File:Acetoxidanflagellum.jpeg2012-12-15T01:09:58Z<p>Jujublah311: image of desulfuromonas acetoxidan flagellum
http://garciajeanlouis9051.perso.neuf.fr/aaBXIII4_O4_5.html</p>
<hr />
<div>image of desulfuromonas acetoxidan flagellum<br />
http://garciajeanlouis9051.perso.neuf.fr/aaBXIII4_O4_5.html</div>Jujublah311https://microbewiki.kenyon.edu/index.php?title=File:Cyclegreenbact.png&diff=78804File:Cyclegreenbact.png2012-12-15T01:08:39Z<p>Jujublah311: original figure showing the mutualism between Green sulfur bacteria and Desulfuromonas acetoxidans</p>
<hr />
<div>original figure showing the mutualism between Green sulfur bacteria and Desulfuromonas acetoxidans</div>Jujublah311https://microbewiki.kenyon.edu/index.php?title=File:Classification.jpeg&diff=78802File:Classification.jpeg2012-12-15T01:06:33Z<p>Jujublah311: Jujublah311 uploaded a new version of &quot;File:Classification.jpeg&quot;: http://www.sciencedirect.com/science/article/pii/S0964830510001721
Modified by adding red box.</p>
<hr />
<div>http://www.sciencedirect.com/science/article/pii/S0964830510001721</div>Jujublah311https://microbewiki.kenyon.edu/index.php?title=File:Classification.jpeg&diff=78801File:Classification.jpeg2012-12-15T01:04:30Z<p>Jujublah311: http://www.sciencedirect.com/science/article/pii/S0964830510001721</p>
<hr />
<div>http://www.sciencedirect.com/science/article/pii/S0964830510001721</div>Jujublah311https://microbewiki.kenyon.edu/index.php?title=File:Cellwall.gif&diff=78799File:Cellwall.gif2012-12-15T01:03:25Z<p>Jujublah311: </p>
<hr />
<div></div>Jujublah311https://microbewiki.kenyon.edu/index.php?title=Desulfuromonas_acetoxidans&diff=78796Desulfuromonas acetoxidans2012-12-15T00:54:58Z<p>Jujublah311: Created page with "==Classification== ===Higher order taxa=== Kingdom: [http://en.wikipedia.org/wiki/Bacteria Bacteria] Phylum: [http://en.wikipedia.org/wiki/Proteobacteria Proteobacteria] Clas..."</p>
<hr />
<div>==Classification==<br />
<br />
===Higher order taxa===<br />
Kingdom: [http://en.wikipedia.org/wiki/Bacteria Bacteria]<br />
Phylum: [http://en.wikipedia.org/wiki/Proteobacteria Proteobacteria]<br />
Class: [http://en.wikipedia.org/wiki/Deltaproteobacteria Deltaproteobacteria]<br />
Order: [http://en.wikipedia.org/wiki/Desulfuromonadales Desulfuromonadales]<br />
Family: Desulfuromonadaceae<br />
Genus: [[Desulfuromonas]]<br />
[7]<br />
<br />
===Species===<br />
{|<br />
| height="10" bgcolor="#FFDF95" |<br />
'''NCBI: [http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=281689 Taxonomy]'''<br />
|}<br />
<br />
Species: ''Acetoxidans'' [7]<br />
<br />
<br />
==Description and significance==<br />
''Desulfuromonas acetoxidans'' was first described in 1976 by N. Pfennig and H. Biebl [10]. The name has a Latin root, meaning “single-celled organism that reduces [http://en.wikipedia.org/wiki/Sulfur sulphur] (''Desulfuromonas'') and oxidizes [http://en.wikipedia.org/wiki/Acetate acetate] (''acetoxidans'')” [6, 10]. It was first described as a sulphur reducing bacteria capable of [http://en.wikipedia.org/wiki/Anaerobic_respiration anaerobically] reducing sulphur to [http://en.wikipedia.org/wiki/Sulfide sulphide] [10]. However, it was later discovered to also possess the ability to perform dissimilatory Fe(III) reduction coupled with the oxidation of organic compounds [11].<br />
<br />
''Desulfuromonas acetoxidans'' is a rod-shaped, [http://en.wikipedia.org/wiki/Gram-negative_bacteria Gram negative] bacterium that is predominantly found in marine sediments [10], though able to survive in fresh water environments [13]. The species is a strict anaerobe that uses a variety of electron donors, such as acetate, ethanol, propanol and butanol, to yield energy [10].<br />
<br />
''Desulfuromonas acetoxidans'' is part of the ''Desulfuromonas'' genus, which has a characteristic of being able to reduce sulphur through the conversion of elemental sulphur into sulphide [10]. ''D. acetoxidans'' is the first species described within the ''Desulfuromonas'' genus, and it is also the first marine microorganism ever described to support growth through Fe(III) or Mn(IV) reduction coupled to the oxidation of organic compounds [11]. <br />
<br />
As the first marine organism ever described to perform the oxidation of organic material coupled with reduction of Fe(III) or Mn(IV), ''D. acetoxidans'' has served as a model organism for the mechanism of Fe(III) or Mn(IV) oxidation of organic compounds [11]. <br />
<br />
<br />
==Genome structure==<br />
The genome sequence of ''D. acetoxidans'' was completed in 2007 with funding from the United states Department of Energy Joint Genome Institute [5]. The sequence is available [http://img.jgi.doe.gov/cgi-bin/w/main.cgi?section=TaxonDetail&taxon_oid=638341078 online] [7], though a formal description of the genome sequence has not been published in a peer-reviewed scientific journal. Its genome is 3.8Mb in length, and codes for 3234 putative genes [7]. A recent study has shown that the genome contains a very large number of genes coding for [http://en.wikipedia.org/wiki/Cytochrome_c c-type cytochromes] with multiple [http://en.wikipedia.org/wiki/Heme heme cofactors] [1]. Studies have found that the genome of ''D. acetoxidans'' codes for 47 possible multiheme cytochrome proteins [3]. A heme cofactor is a prosthetic group found on proteins that have diverse function [5]. In the case of c-type cytochrome, the heme cofactors function as both electron acceptors and electron donors [5]. The large percentage of genes coding for c-type cytochromes have been found to correlate with the ability of ''D. acetoxidans'' to reduce Fe(III) through the dissimilatory pathway [2]. In a study done by Aubert et al. (date, i.e. 2007), the genes that coded for the c-type cytochromes were inserted into the genome of the closely related [http://en.wikipedia.org/wiki/Desulfovibrio ''Desulfovibrio''] ''desulfuricans'', which is unable to reduce metals [3]. The transformed ''D. desulfuricans'' produced the c-type cytochromes and exhibited metal reductase activities [3]. This shows that the c-type cytochrome is vital in the reduction of Fe(III) or Mn(IV) in ''D. acetoxidans''. The mechanistic details concerning how these multiheme cytochromes work are still being studied, but C7 cytochrome is proposed to possess metal reductase activity [2].<br />
<br />
<br />
==Cell structure, metabolism and life cycle==<br />
''D.acetoxidans'' has the following characteristics: i) dimensions of 0.4 - 0.7μm in width and 1 - 4μm in length, ii) a single [http://en.wikipedia.org/wiki/Flagellum flagellum] on the lateral side of the rod-shaped bacteria and even though it possesses a flagellum, most strains were not motile [10]. Its cell envelope resembles those of other gram negative bacteria, with an outer membrane separated from the cytoplasmic membrane by a thin layer of [http://en.wikipedia.org/wiki/Peptidoglycan peptidoglycan] [10]. ''D. acetoxidans'' have been found to be non-sporulating, free living bacterium that divides via [http://en.wikipedia.org/wiki/Fission_(biology)#Binary_fission_of_prokaryotes binary fission] [10].<br />
<br />
''D. acetoxidans'' possesses a complex metabolism, and energy for [http://en.wikipedia.org/wiki/Metabolism metabolism] comes from a variety of redox reactions. They are [http://en.wikipedia.org/wiki/Chemoorganotroph chemoorganotrophs] that respire anaerobically, using acetate, ethanol or propanol as carbon sources and electron donors in the presence of ~0.2mM bicarbonate [10]. These organic carbon sources are completely oxidized to CO2 [6, 10]. When ''D. acetoxidans'' is reducing sulphuric compounds, either elemental sulphur or disulfide bonds within compounds such as malate or fumarate serve as electron acceptors and are reduced to H2S and sulfhydryl-groups, respectively[10]. <br />
<br />
''D. acetoxidans'', when present in different media, has different cytochromes that are present as the dominant type, but there is one type (C7 cytochrome) that is always present, suggesting that this cytochrome plays a key role in metabolism [2]. Studies have also shown that cytochrome C7 plays a role as an electron-transfer protein in the sulphur reduction, as well as in reduction of Fe(III) and Mn(IV) [2]. <br />
<br />
==Ecology==<br />
''Desulfuromonas acetoxidans'' is found primarily in anoxic marine sediment, and rarely found in freshwater sediments [13]. It is able to grow in a pH-range of 6.5 to 8.5, but its optimum pH between 7.2 and 7.5 [10]. ''D. acetoxidans'' has an optimum growth temperature of ~30。C, but it can grow in temperature ranging from 25。C to 35。C [10]. In some environments, ''D. acetoxidans'' grows syntrophically with green sulphur bacteria [4, 8]. Their relationship is mutualistic in that the [http://en.wikipedia.org/wiki/Green_sulfur_bacteria green sulphur bacteria] presents dissolved and readily metabolizable form of sulphur which is used by ''D. acetoxidans'' (refer to figure). The sulphur is oxidized by ''D. acetoxidans'' to sulphur, which the green sulphur bacteria can use [4, 12].<br />
The species has biogeochemical significance as it plays a role in the carbon and sulphur cycles [8]. In carbon contaminant-filled sediments, the environment usually quickly becomes anaerobic. As the environment becomes increasingly anoxic, Fe(III) becomes the most abundant and favourable electron acceptor for organic matter oxidation [8]. ''D. acetoxidans’'' ability to perform dissimilatory Fe(III) reduction can be coupled with the oxidation of organic contaminants, effectively removing them from the environment [8]. Recent studies are focused on the dissimilatory Fe(III) reduction aspect of ''D. acetoxidans'' rather than the sulphur reduction, since Fe(III) reduction signifies the production of electricity through the degradation of organic materials. This has been applied to the creation of [http://en.wikipedia.org/wiki/Microbial_fuel_cell microbial fuel cells], providing enough electricity to power basic electronic equipments [9].<br />
<br />
==References==<br />
[1] [http://www.ncbi.nlm.nih.gov/pubmed/21298162 Alves, A. S., Paquete, C. M., Fonseca, B. M., and Louro, R. O. “Exploration of the ‘cytochrome’ of ''Desulfuromonas acetoxidans'', a Marine Bacterium Capable of Powering Microbial Fuel Cells.” Metallomics, 2011, 3. p. 349–353. DOI: 10.1039/c0mt00084a]<br />
<br />
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[3] [http://www.ncbi.nlm.nih.gov/pubmed/9546165 Aubert, C., Lojou, E., Bianco, P., Rousset, M., Durand, M., Bruschi, M., and Dolla, A. “The Desulfuromonas acetoxidans Triheme Cytochrome C7 Produced in ''Desulfovibrio desulfuricans'' Retains Its Metal Reductase Activity.” Appl. Environ. Microbiol. 1998, 64(4):1308.]<br />
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[4] [http://link.springer.com/article/10.1007%2FBF00689344?LI=true Biebl. H., Pfennig, N. “Growth Yields of Green Sulfur Bacteria in Mixed Cultures with Sulfur and Sulfate Reducing Bacteria.” Arch. Microbiol. 1978. 117, p. 9 -16.]<br />
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[6] [http://link.springer.com/article/10.1007%2FBF00428855?LI=true Gebhard , N. A., Thauer, R. K., Linder, D., Kaulfers, P., Pfennig, N. “Mechanism of acetate oxidation to CO2 with elemental sulfur in ''Desulfuromonas acetoxidans''.” Arch Microbiol (1985) 141:392-98.]<br />
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[7] [http://www.ncbi.nlm.nih.gov/pubmed/21896772 Gillespie, J. J., Wattam, A. R., Cammer, S. A., Gabbard, J., Shukla, M. P., Dalay, O., Driscoll, T., Hix, D., Mane, S. P., Mao, C., Nordberg, E. K., Scott, M., Schulman, J. R., Snyder, E. E., Sullivan, D. E. Wang, C., Warren, A., Williams, K. P., Xue, T., Yoo, H. S., Zhang, C., Zhang, Y., Will, R., Kenyon, R.W. and Sobral B. W. (2011). “PATRIC: The Comprehensive Bacterial Bioinformatics Resource with a Focus on Human Pathogenic Species” Infect. Immun 79 (11): 4286-98. doi:10.1128/IAI.00207-11. PMID21896772.PMC3257917.]<br />
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[11] [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC202183/ Roden, E. R., Lovley, D. R. “Dissimilatory Fe(III) Reduction by the Marine Microorganism ''Desulfuromonas acetoxidans''.” Applied and Environmental Microbiology. 1993, 59(3). p. 734-42.]<br />
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[12] [http://link.springer.com/article/10.1007%2FBF00248679?LI=true Warthmann, R., Cypionka, H., Pfennig, N. “Photoproduction of H2 from acetate by syntrophic cocultures of green sulfur bacteria and sulfur-reducing bacteria.” Arch Microbiol (1992), 157: 343-48.]<br />
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[13] [http://www.ncbi.nlm.nih.gov/pubmed/16627667 Vandieken, V., Mußmann, B., Niemann, H., Jørgensen, B. B. “''Desulfuromonas svalbardensis'' sp. nov. and ''Desulfuromusa ferrireducens'' sp. nov., psychrophilic, Fe(III)-reducing bacteria isolated from Arctic sediments, Svalbard.” International Journal of Systematic and Evolutionary Microbiology (2006), 56: 1133–1139 DOI 10.1099.]</div>Jujublah311https://microbewiki.kenyon.edu/index.php?title=User:Jujublah311&diff=78766User:Jujublah3112012-12-14T23:57:49Z<p>Jujublah311: Created page with "I’m a microbiology and immunology student at the University of British Columbia."</p>
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<div>I’m a microbiology and immunology student at the University of British Columbia.</div>Jujublah311