scholarly journals Sulfur-mediated electron shuttling during bacterial iron reduction

Science ◽  
2014 ◽  
Vol 344 (6187) ◽  
pp. 1039-1042 ◽  
Author(s):  
T. M. Flynn ◽  
E. J. O'Loughlin ◽  
B. Mishra ◽  
T. J. DiChristina ◽  
K. M. Kemner
Keyword(s):  
Iron Reduction ◽  
Electron Shuttling

Reductive Leaching of Jarosites by Shewanella putrefaciens - Influence of Humic Substances and Chelators in Mineral Dissolution

2015 ◽  
Vol 1130 ◽  
pp. 450-453 ◽  
Author(s):  
Laura Castro ◽  
J.A. Muñoz ◽  
F. González ◽  
M. Luisa Blázquez ◽  
Antonio Ballester
Keyword(s):  
Humic Substances ◽  
Biofilm Formation ◽  
Iron Reduction ◽  
Cell Attachment ◽  
Reduction Rate ◽  
Shewanella Putrefaciens ◽  
Microbial Reduction ◽  
Mineral Dissolution ◽  
Electron Shuttling ◽  
Reductive Leaching

The anaerobic bioreduction of three Fe (III) ores by a type strain of Shewanella putrefaciens has been investigated. The release of ferrous ion indicated the microbial reduction of jarosite and promotes the subsequent secondary mineralization, leading to the formation of various iron-nearing minerals. In addition, the influence of citrate and EDTA in the medium acting as chelating agents, and an electron shuttling molecule were studied. While the citrate and humic substances increased the iron reduction rate, AQDS inhibit the mineral bioreduction and dissolution. S. putrefaciens do not have the necessity of the direct contact between cells and jarosites and, in consequence, cell attachment and biofilm formation on the mineral surface is scant.

scholarly journals Macroalgae degradation promotes microbial iron reduction via electron shuttling in coastal Antarctic sediments

2021 ◽  
Vol 156 ◽  
pp. 106602
Author(s):  
David A. Aromokeye ◽  
Graciana Willis-Poratti ◽  
Lea C. Wunder ◽  
Xiuran Yin ◽  
Jenny Wendt ◽  
...  
Keyword(s):  
Iron Reduction ◽  
Electron Shuttling ◽  
Microbial Iron Reduction

scholarly journals Evaluation of electron-shuttling compounds in microbial ferric iron reduction

2003 ◽  
Vol 220 (2) ◽  
pp. 229-233 ◽  
Author(s):  
Kristina L Straub ◽  
Bernhard Schink
Keyword(s):  
Iron Reduction ◽  
Ferric Iron ◽  
Electron Shuttling

scholarly journals Shewanella oneidensis MR-1 Uses Overlapping Pathways for Iron Reduction at a Distance and by Direct Contact under Conditions Relevant for Biofilms

2005 ◽  
Vol 71 (8) ◽  
pp. 4414-4426 ◽  
Author(s):  
Douglas P. Lies ◽  
Maria E. Hernandez ◽  
Andreas Kappler ◽  
Randall E. Mielke ◽  
Jeffrey A. Gralnick ◽  
...  
Keyword(s):  
Direct Contact ◽  
Iron Reduction ◽  
Shewanella Oneidensis ◽  
Live Cells ◽  
Wild Type ◽  
Electron Shuttling ◽  
Electron Shuttles ◽  
Diffusion Limited ◽  
Culture Supernatants ◽  
Maximal Reduction

ABSTRACT We developed a new method to measure iron reduction at a distance based on depositing Fe(III) (hydr)oxide within nanoporous glass beads. In this “Fe-bead” system, Shewanella oneidensis reduces at least 86.5% of the iron in the absence of direct contact. Biofilm formation accompanies Fe-bead reduction and is observable both macro- and microscopically. Fe-bead reduction is catalyzed by live cells adapted to anaerobic conditions, and maximal reduction rates require sustained protein synthesis. The amount of reactive ferric iron in the Fe-bead system is available in excess such that the rate of Fe-bead reduction is directly proportional to cell density; i.e., it is diffusion limited. Addition of either lysates prepared from anaerobic cells or exogenous electron shuttles stimulates Fe-bead reduction by S. oneidensis, but iron chelators or additional Fe(II) do not. Neither dissolved Fe(III) nor electron shuttling activity was detected in culture supernatants, implying that the mediator is retained within the biofilm matrix. Strains with mutations in omcB or mtrB show about 50% of the wild-type levels of reduction, while a cymA mutant shows less than 20% of the wild-type levels of reduction and a menF mutant shows insignificant reduction. The Fe-bead reduction defect of the menF mutant can be restored by addition of menaquinone, but menaquinone itself cannot stimulate Fe-bead reduction. Because the menF gene encodes the first committed step of menaquinone biosynthesis, no intermediates of the menaquinone biosynthetic pathway are used as diffusible mediators by this organism to promote iron reduction at a distance. CymA and menaquinone are required for both direct and indirect mineral reduction, whereas MtrB and OmcB contribute to but are not absolutely required for iron reduction at a distance.

PH DEPENDENT INTERACTIONS BETWEEN IRON REDUCTION AND METHANOGENESIS SUGGEST A NEW MODEL FOR METHANOGENESIS

2018 ◽  
Author(s):  
Matthew F. Kirk ◽  
◽  
Qusheng Jin ◽  
Theodore M. Flynn ◽  
Lydia H. Zeglin
Keyword(s):  
Iron Reduction ◽  
New Model ◽  
Ph Dependent

Effects and mechanisms of modified biochars on microbial iron reduction of Geobacter sulfurreducens

Chemosphere ◽  
2021 ◽  
pp. 130983
Author(s):  
Yue Lu ◽  
Yingju Hu ◽  
Lin Tang ◽  
Qingqing Xie ◽  
Qian Liu ◽  
...  
Keyword(s):  
Iron Reduction ◽  
Geobacter Sulfurreducens ◽  
Microbial Iron Reduction
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