Periplasmic Cytochrome c3 of Desulfovibrio vulgaris Is Directly Involved in H2-Mediated Metal but Not Sulfate Reduction (original) (raw)
Related papers
Sulfate-reducing bacterium grows with Cr(VI), U(VI), Mn(IV), and Fe(III) as electron acceptors
FEMS Microbiology Letters, 1998
A spore-forming sulfate-reducing bacterium Desulfotomaculum reducens sp. nov. strain MI-1 has been isolated from heavy metal contaminated sediments. Strain MI-1 grows with Cr(VI), Mn(IV), Fe(III), and U(VI), in addition to various sulfur compounds, as electron acceptors. This organism shares physiological properties with both the sulfate-reducing and metalreducing groups of bacteria and is the first sulfate-reducing bacterium described that can grow with metals or U(VI) as sole electron acceptors. z
Biochemistry, physiology and biotechnology of sulfate-reducing bacteria
Advances in applied microbiology, 2009
Chemolithotrophic bacteria that use sulfate as terminal electron acceptor (sulfate-reducing bacteria) constitute a unique physiological group of microorganisms that couple anaerobic electron transport to ATP synthesis. These bacteria (220 species of 60 genera) can use a large variety of compounds as electron donors and to mediate electron flow they have a vast array of proteins with redox active metal groups. This chapter deals with the distribution in the environment and the major physiological and metabolic characteristics of sulfate-reducing bacteria (SRB). This chapter presents our current knowledge of soluble electron transfer proteins and transmembrane redox complexes that are playing an essential role in the dissimilatory sulfate reduction pathway of SRB of the genus Desulfovibrio. Environmentally important activities displayed by SRB are a consequence of the unique electron transport components or the production of high levels of H(2)S. The capability of SRB to utilize hydro...
Fe(III) reduction during pyruvate fermentation by Desulfotomaculum reducens strain MI-1
Geobiology, 2014
Desulfotomaculum reducens MI-1 is a Gram-positive, sulfate-reducing bacterium also capable of reducing several metals, among which is Fe(III). Very limited knowledge is available on the potential mechanism(s) of metal reduction among Gram-positive bacteria, despite their preponderance in the microbial communities that inhabit some inhospitable environments (e.g., thermal or hyperthermal ecosystems, extreme pH or salinity environments, heavy metal or radionuclide contaminated sediments). Here, we show that in the presence of pyruvate, this micro-organism is capable of reducing both soluble Fe(III)-citrate and solid-phase hydrous ferric oxide, although growth is sustained by pyruvate fermentation rather than Fe(III) respiration. Despite the fact that Fe(III) reduction does not support direct energy conservation, D. reducens uses it as a complementary means of discarding excess reducing equivalent after H 2 accumulation in the culture headspace renders proton reduction unfavorable. Thus, Fe(III) reduction permits the oxidation of greater amounts of pyruvate than fermentation alone. Fe(III) reduction by D. reducens is mediated by a soluble electron carrier, most likely riboflavin. Additionally, an intracellular electron storage molecule acts as a capacitor and accumulates electrons during pyruvate oxidation for slow release to Fe(III). The reductase responsible for the transfer of electrons from the capacitor to the soluble carrier has not been identified, but data presented here argue against the involvement of c-type cytochromes.
Applied and environmental microbiology, 2013
Updated information and services can be found at: These include: SUPPLEMENTAL MATERIAL Supplemental material REFERENCES http://aem.asm.org/content/79/7/2172#ref-list-1 at: This article cites 59 articles, 17 of which can be accessed free CONTENT ALERTS more» articles cite this article), Receive: RSS Feeds, eTOCs, free email alerts (when new http://journals.asm.org/site/misc/reprints.xhtml Information about commercial reprint orders: http://journals.asm.org/site/subscriptions/ To subscribe to to another ASM Journal go to: on April 5, 2013 by INIST-CNRS BiblioVie
Sulfur-Mediated Electron Shuttling During Bacterial Iron Reduction
Science, 2014
Microbial reduction of ferric iron [Fe(III)] is an important biogeochemical process in anoxic aquifers. Depending upon groundwater pH, dissimilatory metal-reducing bacteria (DMRB) can also respire alternative electron acceptors to survive, including elemental sulfur (S 0). To understand the interplay of Fe/S cycling under alkaline conditions, we combined thermodynamic geochemical modeling with bioreactor experiments using Shewanella oneidensis MR-1. Under these conditions, S. oneidensis can enzymatically reduce S 0 but not goethite (-FeOOH). The HSproduced subsequently reduces goethite abiotically. Due to the prevalence of alkaline conditions in many aquifers, Fe(III) reduction may thus proceed via S 0mediated electron-shuttling pathways whereby DMRB may require an active sulfate-reducing bacterial partner to respire.
FEBS Journal, 2007
Shewanella oneidensis MR-1 is a Gram-negative c-proteobacterium with an extremely versatile anaerobic respiratory metabolism. Under anaerobic conditions, this organism reduces a variety of organic and inorganic substrates, including fumarate, nitrate, trimethylamine N-oxide, dimethylsulfoxide, sulfite and thiosulfate, as well as various polyvalent metal ions and radionuclides, including iron(III), manganese(IV), chromium(VI), vanadium(V), selenium(VI), uranium(VI), and tellurium(VI) . Bacterial dissimilatory metal
Research in microbiology, 2016
To clarify the pathway of anaerobic sulfur oxidation coupled with dissimilatory ferric iron reduction in Acidithiobacillus ferrooxidans strain CCM 4253 cells, we monitored their energy metabolism gene transcript profiles. Several genes encoding electron transporters involved in aerobic iron and sulfur respiration were induced during anaerobic growth of ferrous iron-grown cells. Most sulfur metabolism genes were either expressed at the basal level or their expression declined. However, transcript levels of genes assumed to be responsible for processing of elemental sulfur and other sulfur intermediates were elevated at the beginning of the growth period. In contrast, genes with predicted functions in formation of hydrogen sulfide and sulfate were significantly repressed. The main proposed mechanism involves: outer membrane protein Cyc2 (assumed to function as a terminal ferric iron reductase); periplasmic electron shuttle rusticyanin; c4-type cytochrome CycA1; the inner membrane cyto...
THE EFFECT OF Fe(III) ON THE RATE OF MICROBIAL SULFATE- REDUCTION
2013
The effect of threevalent iron (Fe(OH)3) on microbial dissimilatory sulfate-reduction was studied in batch conditions with use of three different donors of electrons - Na-lactate, Na-acetate and solid organic matter (cow manure, spent mushroom compost and sawdust). The inoculum (mixed culture of sulfate-reducing and other metabolically related groups of microorganisms) was received from anaerobic cell for treatment of acid mine drainage. It was found maximal rate of the process sulfate reduction (147 mg SO4 2- /l.d) when lactate was used as sole source of carbon and energy. The Fe(III) reduction was prevalent process with acetate as donor of electrons (the rate of sulfate-reduction was only 13 mg SO4 2- /l.d). It was found that in the conditions, typical for anaerobic passive treatment, the rate of reduction of threevalent iron also is higher than the rate of sulfate- reduction. A part from reduced iron precipitated in the form of FeS. The concentrations of soluble Fe 2+ when using ...