Biochemical and functional insights on the triheme cytochrome PpcA from Geobacter metallireducens

2018 ◽  
Vol 644 ◽  
pp. 8-16 ◽  
Author(s):  
Pilar C. Portela ◽  
Tomás M. Fernandes ◽  
Joana M. Dantas ◽  
Marisa R. Ferreira ◽  
Carlos A. Salgueiro
Keyword(s):  
Geobacter Metallireducens

Exemplar Abstract for Geobacter metallireducens Lovley et al. 1995.

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity
Keyword(s):  
Geobacter Metallireducens

Exemplar Abstract for Geobacter metallireducens Lovley et al. 1995.

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Sarah Wigley ◽  
George M Garrity
Keyword(s):  
Geobacter Metallireducens

scholarly journals Evaluation of a Genome-ScaleIn SilicoMetabolic Model for Geobacter metallireducens by Using Proteomic Data from a Field Biostimulation Experiment

2012 ◽  
Vol 78 (24) ◽  
pp. 8735-8742 ◽  
Author(s):  
Yilin Fang ◽  
Michael J. Wilkins ◽  
Steven B. Yabusaki ◽  
Mary S. Lipton ◽  
Philip E. Long
Keyword(s):  
Proteomic Analysis ◽  
In Silico ◽  
Field Experiments ◽  
Metabolic Model ◽  
Geobacter Metallireducens ◽  
Content Type ◽  
Proteomic Data ◽  
Subsurface Environment ◽  
A Genome ◽  
Genome Scale

ABSTRACTAccurately predicting the interactions between microbial metabolism and the physical subsurface environment is necessary to enhance subsurface energy development, soil and groundwater cleanup, and carbon management. This study was an initial attempt to confirm the metabolic functional roles within anin silicomodel using environmental proteomic data collected during field experiments. Shotgun global proteomics data collected during a subsurface biostimulation experiment were used to validate a genome-scale metabolic model ofGeobacter metallireducens—specifically, the ability of the metabolic model to predict metal reduction, biomass yield, and growth rate under dynamic field conditions. The constraint-basedin silicomodelof G. metallireducensrelates an annotated genome sequence to the physiological functions with 697 reactions controlled by 747 enzyme-coding genes. Proteomic analysis showed that 180 of the 637G. metallireducensproteins detected during the 2008 experiment were associated with specific metabolic reactions in thein silicomodel. When the field-calibrated Fe(III) terminal electron acceptor process reaction in a reactive transport model for the field experiments was replaced with the genome-scale model, the model predicted that the largest metabolic fluxes through thein silicomodel reactions generally correspond to the highest abundances of proteins that catalyze those reactions. Central metabolism predicted by the model agrees well with protein abundance profiles inferred from proteomic analysis. Model discrepancies with the proteomic data, such as the relatively low abundances of proteins associated with amino acid transport and metabolism, revealed pathways or flux constraints in thein silicomodel that could be updated to more accurately predict metabolic processes that occur in the subsurface environment.

scholarly journals Direct Interspecies Electron Transfer between Geobacter metallireducens and Methanosarcina barkeri

2014 ◽  
Vol 80 (15) ◽  
pp. 4599-4605 ◽  
Author(s):  
Amelia-Elena Rotaru ◽  
Pravin Malla Shrestha ◽  
Fanghua Liu ◽  
Beatrice Markovaite ◽  
Shanshan Chen ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Model Organism ◽  
Methanosarcina Barkeri ◽  
Physical Contact ◽  
Acetate Metabolism ◽  
Geobacter Metallireducens ◽  
Content Type ◽  
Direct Interspecies Electron Transfer ◽  
Interspecies Electron Transfer ◽  
Effective Form

ABSTRACTDirect interspecies electron transfer (DIET) is potentially an effective form of syntrophy in methanogenic communities, but little is known about the diversity of methanogens capable of DIET. The ability ofMethanosarcina barkerito participate in DIET was evaluated in coculture withGeobacter metallireducens. Cocultures formed aggregates that shared electrons via DIET during the stoichiometric conversion of ethanol to methane. Cocultures could not be initiated with a pilin-deficientG. metallireducensstrain, suggesting that long-range electron transfer along pili was important for DIET. Amendments of granular activated carbon permitted the pilin-deficientG. metallireducensisolates to share electrons withM. barkeri, demonstrating that this conductive material could substitute for pili in promoting DIET. WhenM. barkeriwas grown in coculture with the H2-producingPelobacter carbinolicus, incapable of DIET,M. barkeriutilized H2as an electron donor but metabolized little of the acetate thatP. carbinolicusproduced. This suggested that H2, but not electrons derived from DIET, inhibited acetate metabolism.P. carbinolicus-M. barkericocultures did not aggregate, demonstrating that, unlike DIET, close physical contact was not necessary for interspecies H2transfer.M. barkeriis the second methanogen found to accept electrons via DIET and the first methanogen known to be capable of using either H2or electrons derived from DIET for CO2reduction. Furthermore,M. barkeriis genetically tractable, making it a model organism for elucidating mechanisms by which methanogens make biological electrical connections with other cells.

scholarly journals The triheme cytochrome PpcF from Geobacter metallireducens exhibits distinct redox properties

FEBS Open Bio ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1897-1910 ◽  
Author(s):  
Marisa R. Ferreira ◽  
Joana M. Dantas ◽  
Carlos A. Salgueiro
Keyword(s):  
Redox Properties ◽  
Geobacter Metallireducens

scholarly journals Effect of Geobacter metallireducens nanowire on electron transfer efficiency in MFC

2021 ◽  
Author(s):  
Shunliang Liu ◽  
feng ya li ◽  
li hao ran
Keyword(s):  
Electron Transfer ◽  
Electrochemical Measurement ◽  
Inhibitory Effect ◽  
Transfer Efficiency ◽  
Maximum Output ◽  
Current Response ◽  
Electron Mediator ◽  
Geobacter Metallireducens ◽  
Culture Process ◽  
Double Chamber

Inhibitory effect of electron mediator AQDS on Geobacter metallireducens nanowire in microbial fuel cell (MFC) was studied. In the culture process of G. metallireducens with Fe(OH)3 as electron acceptor, the concentration of reduction product Fe (II) in solution without AQDS is higher than that with AQDS after 10 days, due to the formation of microbial nanowires. The effects of nanowire on electron transfer efficiency and power generation characteristic were studied using double chamber MFC reactor. The transfer efficiency between biofilm and electrodes was increased by nanowire, which increases maximum output voltage of MFC from 321 mV to 442 mV. The nanowire biofilm electrode has the bigger cyclic voltammetry curve peak, smaller activation resistance and stronger current response signal through electrochemical measurement, which indicated that the nanowire enhanced the electrochemical activity of the electrode.

scholarly journals Putative Extracellular Electron Transfer in Methanogenic Archaea

2021 ◽  
Vol 12 ◽  
Author(s):  
Kailin Gao ◽  
Yahai Lu
Keyword(s):  
Electron Transfer ◽  
Methanogenic Archaea ◽  
Methanosarcina Barkeri ◽  
Extracellular Electron Transfer ◽  
Future Research ◽  
Methanosarcina Acetivorans ◽  
Geobacter Metallireducens ◽  
Methanosarcina Mazei ◽  
Current State ◽  
Electron Transfers

It has been suggested that a few methanogens are capable of extracellular electron transfers. For instance, Methanosarcina barkeri can directly capture electrons from the coexisting microbial cells of other species. Methanothrix harundinacea and Methanosarcina horonobensis retrieve electrons from Geobacter metallireducens via direct interspecies electron transfer (DIET). Recently, Methanobacterium, designated strain YSL, has been found to grow via DIET in the co-culture with Geobacter metallireducens. Methanosarcina acetivorans can perform anaerobic methane oxidation and respiratory growth relying on Fe(III) reduction through the extracellular electron transfer. Methanosarcina mazei is capable of electromethanogenesis under the conditions where electron-transfer mediators like H2 or formate are limited. The membrane-bound multiheme c-type cytochromes (MHC) and electrically-conductive cellular appendages have been assumed to mediate the extracellular electron transfer in bacteria like Geobacter and Shewanella species. These molecules or structures are rare but have been recently identified in a few methanogens. Here, we review the current state of knowledge for the putative extracellular electron transfers in methanogens and highlight the opportunities and challenges for future research.

scholarly journals One-megadalton metalloenzyme complex inGeobacter metallireducensinvolved in benzene ring reduction beyond the biological redox window

2019 ◽  
Vol 116 (6) ◽  
pp. 2259-2264 ◽  
Author(s):  
Simona G. Huwiler ◽  
Claudia Löffler ◽  
Sebastian E. L. Anselmann ◽  
Hans-Joachim Stärk ◽  
Martin von Bergen ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Benzene Ring ◽  
Active Site ◽  
Anaerobic Bacterium ◽  
Class Ii ◽  
High Molecular Mass ◽  
Redox Potentials ◽  
Geobacter Metallireducens ◽  
Redox Couples ◽  
Biological Electron Transfer

Reversible biological electron transfer usually occurs between redox couples at standard redox potentials ranging from +0.8 to −0.5 V. Dearomatizing benzoyl-CoA reductases (BCRs), key enzymes of the globally relevant microbial degradation of aromatic compounds at anoxic sites, catalyze a biological Birch reduction beyond the negative limit of this redox window. The structurally characterized BamBC subunits of class II BCRs accomplish benzene ring reduction at an active-site tungsten cofactor; however, the mechanism and components involved in the energetic coupling of endergonic benzene ring reduction have remained hypothetical. We present a 1-MDa, membrane-associated, Bam[(BC)2DEFGHI]2complex from the anaerobic bacteriumGeobacter metallireducensharboring 4 tungsten, 4 zinc, 2 selenocysteines, 6 FAD, and >50 FeS cofactors. The results suggest that class II BCRs catalyze electron transfer to the aromatic ring, yielding a cyclic 1,5-dienoyl-CoA via two flavin-based electron bifurcation events. This work expands our knowledge of energetic couplings in biology by high-molecular-mass electron bifurcating machineries.

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