:Geopsychrobacter electrodiphilus

Geopsychrobacter electrodiphilus was isolated from the surface of an electrode (anode) of a marine sediment fuel cell. The sediments come from a water depth of 5 meters (Boston Harbor, Massachusetts, near the peninsula World's End).

The name "Geopsychrobacter electrodiphilus" means somewhat like "electrode-loving rod of cold earth" and indicates that the microbe comes from the surface (earth, Geo), copes with cold ({{transliteration|grc|psychro}}), is rod-shaped ({{transliteration|grc|bacter}}) and was isolated from electrodes ({{transliteration|grc|electrodi}}), which it has voluntarily settled ({{transliteration|grc|philus}}).

Two strains of Geopsychrobacter electrodiphilus were isolated (A1 and A2); Strain A1 was determined as the type strain (A1^T; ATCC BAA-880^T; DSM 16401^T; JCM 12469) of the species Geopsychrobacter electrodiphilus and as the type strain of the genus.

In a study on the cultivation of microbial communities in sludge, where sulphate reducers are likely to benefit, the proportion of Geopsychrobacter decreased.{{cite journal | vauthors = Zeng GQ, Jia XS, Zheng XH, Yang LP, Sun GP | title = [Analysis of microbial community variation in the domestication process of sludge in a sulfate-reducing reactor] | journal = Huan Jing Ke Xue = Huanjing Kexue | volume = 35 | issue = 11 | pages = 4244–50 | date = November 2014 | pmid = 25639102 }} An investigation of bacterial diversity in the cold outflow of an iron oxide-tainted plume of saltwater (Blood Falls, Antarctica) indicated about 11% of cells as G. electrodiphilus.{{cite journal | vauthors = Mikucki JA, Priscu JC | title = Bacterial diversity associated with Blood Falls, a subglacial outflow from the Taylor Glacier, Antarctica | journal = Applied and Environmental Microbiology | volume = 73 | issue = 12 | pages = 4029–39 | date = June 2007 | pmid = 17468282 | pmc = 1932727 | doi = 10.1128/AEM.01396-06 | bibcode = 2007ApEnM..73.4029M }} The plume were identified as a subglacial “ocean”, where coupled biogeochemical processes below the glacier enable microbes to grow in extended isolation, accumulating iron(II) despite the presence of an active sulfur cycle.{{cite journal | vauthors = Mikucki JA, Pearson A, Johnston DT, Turchyn AV, Farquhar J, Schrag DP, Anbar AD, Priscu JC, Lee PA | title = A contemporary microbially maintained subglacial ferrous "ocean" | journal = Science | volume = 324 | issue = 5925 | pages = 397–400 | date = April 2009 | pmid = 19372431 | doi = 10.1126/science.1167350 | bibcode = 2009Sci...324..397M | s2cid = 44802632 }}

{{Citation needed|date=November 2021|reason=inappropriate place for the sentence: {This bacteria is naturally found underground in water streams and in swamps where plant matter can easily reach it.} The following two sentences contain general information about bacteria unrelated to Geopsychrobacter: "The bacteria lives on metal and to do so it releases electrons into the metal. Bacteria cannot live on most heavy metals but the release of electrons help counter Oligodynamic effect."}} Holmes et al. 2004 proposed a likely mechanism for a special microbial fuel cell (sediment fuel cell), to support energy with help of G. electrodiphilus and other microbes of a community in marine sediments; based on the article, this imaginary mechanism is summarized here:

• Some microbes digest complex organic matter (fermentation) in an anaerobic{{efn|In this context, “anaerobic” is a place without oxygen. See also “anaerobic organism”/ “aerobic organism”.|name=|group=}} part of the sediment fuel cell nearby a graphite electrode (anode). G. electrodiphilus grows on the surface of this graphite electrode and oxidize fermentation products, e.g. acetate. Normally, those oxidation processes produce carbon dioxide, protons and electrons and any oxidation has to be coupled to a reduction, because of the electrons. G. electrodiphilus could use a terminal electron acceptor, e.g. poorly crystallized iron(III) oxide (that would be reduced to magnetite) when available. In a sediment fuel cell, G. electrodiphilus has direct contact to the electrode and can use it as a sole electron acceptor. The electrode in the anaerobic part of the sediment fuel cell (anode) has connection to its counterelectrode (cathode) in the overlying aerobic{{efn|In this context, “aerobic” is a place with oxygen. See also “aerobic organism”/ “anaerobic organism”.|name=|group=}} water. The electrons flow from the anode to the cathode in the overlying aerobic water, where they likely reduce oxygen.

To explain their proposal for the process inside the sediment fuel cell, authors referred to previous investigations.{{cite journal | vauthors = Bond DR, Lovley DR | title = Electricity production by Geobacter sulfurreducens attached to electrodes | journal = Applied and Environmental Microbiology | volume = 69 | issue = 3 | pages = 1548–55 | date = March 2003 | pmid = 12620842 | pmc = 150094 | doi = 10.1128/AEM.69.3.1548-1555.2003 | bibcode = 2003ApEnM..69.1548B }}{{cite journal | vauthors = Tender LM, Reimers CE, Stecher HA, Holmes DE, Bond DR, Lowy DA, Pilobello K, Fertig SJ, Lovley DR | title = Harnessing microbially generated power on the seafloor | journal = Nature Biotechnology | volume = 20 | issue = 8 | pages = 821–5 | date = August 2002 | pmid = 12091916 | doi = 10.1038/nbt716 | s2cid = 927966 }}{{cite journal | vauthors = Reimers CE, Tender LM, Fertig S, Wang W | title = Harvesting energy from the marine sediment--water interface | journal = Environmental Science & Technology | volume = 35 | issue = 1 | pages = 192–5 | date = January 2001 | pmid = 11352010 | doi = 10.1021/es001223s | bibcode = 2001EnST...35..192R }}

Holmes et al. (2004) did not investigate microbial communities or technical devices; the aim of their investigations was to find organisms that transfer electrons to an electrode and to describe them. The G. electrodiphilus strains were able to oxidize acetate, malate, fumarate, and citrate with electron transfer to an electrode poised at +0.52 V (in reference to a standard hydrogen electrode).

One key point of harvesting energy using a sediment fuel cell seems to bridge the anaerobic environment of G. electrodiphilus and the aerobic water; the difference in redox potentials can be used.

Reduction of poorly crystalline Fe(III) oxide results in the formation of magnetite. It is therefore conceivable that the oligodynamic effect in Geopsychrobacter is low and an application with metallic components inside a technical device would be possible.

• Exoelectrogen

{{notelist}}

{{Reflist}}

{{refbegin}}

• {{cite book | veditors = Vos P, Garrity G, Jones D, Krieg NR, Ludwig W, Rainey FA, Schleifer KH, Whitman W | vauthors = Staley JT, etal | title = Bergey's manual of systematic bacteriology | volume = 3: The Firmicutes | publisher = Williams and Wilkins | location = Baltimore, MD | date = 1989 | pages = 2250–2251 }}
• {{cite book | veditors = Hallenbeck PC | title = Microbial technologies in advanced biofuels production. | publisher = Springer | date = 2011 }}
• {{cite thesis | vauthors = Zuo Y | title = Novel electrochemical material applications and exoelectrogenic bacteria isolation from microbial fuel cells (MFCs) | degree = Ph.D. | publisher = The Pennsylvania State University | url = https://etda.libraries.psu.edu/files/final_submissions/6943 }}

{{refend}}

• [https://lpsn.dsmz.de/genus/geopsychrobacter LPSN]
• {{EOL}}
• [http://www.marinespecies.org/aphia.php?p=taxdetails&id=396090 WORMS entry]
• [http://bacdive.dsmz.de/index.php?search=5789&submit=Search Type strain of Geopsychrobacter electrodiphilus at BacDive – the Bacterial Diversity Metadatabase]

{{Taxonbar|from=Q16982265}}

{{DEFAULTSORT:Geopsychrobacter electrodiphilus}}

Category:Desulfuromonadales

Category:Bacteria described in 2005