scholarly journals NADH dehydrogenases contribute to extracellular electron transfer byShewanella oneidensisMR-1 in bioelectrochemical systems

2019 ◽  
Author(s):  
Cody S. Madsen ◽  
Michaela A. TerAvest
Keyword(s):  
Electron Transfer ◽  
Shewanella Oneidensis ◽  
Extracellular Electron Transfer ◽  
Growth Defect ◽  
Bioelectrochemical Systems ◽  
Terminal Electron Acceptor ◽  
Nadh Dehydrogenases ◽  
Level Of Understanding ◽  
High Level

AbstractShewanella oneidensisMR-1 is quickly becoming a synthetic biology workhorse for bioelectrochemical technologies due to a high level of understanding of its interaction with electrodes. Transmembrane electron transfer via the Mtr pathway has been well characterized, however, the role of NADH dehydrogenases in feeding electrons to Mtr has been only minimally studied inS. oneidensisMR-1. Four NADH dehydrogenases are encoded in the genome, suggesting significant metabolic flexibility in oxidizing NADH under a variety of conditions. Strains containing in-frame deletions of each of these dehydrogenases were grown in anodic bioelectrochemical systems with N-acetylglucosamine or D,L-lactate as the carbon source to determine impact on extracellular electron transfer. A strain lacking the two dehydrogenases essential for aerobic growth exhibited a severe growth defect with an anode (+0.4 VSHE) or Fe(III)-NTA as the terminal electron acceptor. Our study reveals that the same NADH dehydrogenase complexes are utilized under oxic conditions or with a high potential anode. Understanding the role of NADH in extracellular electron transfer may help improve biosensors and give insight into other applications for bioelectrochemical systems.TOC Graphic

scholarly journals NADH dehydrogenases Nuo and Nqr1 contribute to extracellular electron transfer by Shewanella oneidensis MR-1 in bioelectrochemical systems

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Cody S. Madsen ◽  
Michaela A. TerAvest
Keyword(s):  
Electron Transfer ◽  
Shewanella Oneidensis ◽  
Extracellular Electron Transfer ◽  
Growth Defect ◽  
Bioelectrochemical Systems ◽  
Terminal Electron Acceptor ◽  
Nadh Dehydrogenases ◽  
Level Of Understanding ◽  
High Level

Abstract Shewanella oneidensis MR-1 is quickly becoming a synthetic biology workhorse for bioelectrochemical technologies due to a high level of understanding of its interaction with electrodes. Transmembrane electron transfer via the Mtr pathway has been well characterized, however, the role of NADH dehydrogenases in feeding electrons to Mtr has been only minimally studied in S. oneidensis MR-1. Four NADH dehydrogenases are encoded in the genome, suggesting significant metabolic flexibility in oxidizing NADH under a variety of conditions. A strain lacking the two dehydrogenases essential for aerobic growth exhibited a severe growth defect with an anode (+0.4 VSHE) or Fe(III)-NTA as the terminal electron acceptor. Our study reveals that the same NADH dehydrogenase complexes are utilized under oxic conditions or with a high potential anode. Our study also supports the previously indicated importance of pyruvate dehydrogenase activity in producing NADH during anerobic lactate metabolism. Understanding the role of NADH in extracellular electron transfer may help improve biosensors and give insight into other applications for bioelectrochemical systems.

Impact of Graphitic Structures in Pyrogenic Carbon on Microbial Reduction of Ferrihydrite

2021 ◽  
Author(s):  
wentao yu ◽  
baoliang chen
Keyword(s):  
Electron Transfer ◽  
Pyrolysis Temperature ◽  
Shewanella Oneidensis ◽  
Exchange Capacity ◽  
Microbial Reduction ◽  
Systematic Evaluation ◽  
Extracellular Electron Transfer ◽  
Pyrogenic Carbon ◽  
The Impact

<p>Pyrogenic carbon plays important roles in microbial reduction of ferrihydrite by shuttling electrons in the extracellular electron transfer (EET) processes. Despite its importance, a full assessment on the impact of graphitic structures in pyrogenic carbon on microbial reduction of ferrihydrite has not been conducted. This study is a systematic evaluation of microbial ferrihydrite reduction by Shewanella oneidensis MR-1 in the presence of pyrogenic carbon with various graphitization extents. The results showed that the rates and extents of microbial ferrihydrite reduction were significantly enhanced in the presence of pyrogenic carbon, and increased with increasing pyrolysis temperature. Combined spectroscopic and electrochemical analyses suggested that the rate of microbial ferrihydrite reduction were dependent on the electrical conductivity of pyrogenic carbon (i.e., graphitization extent), rather than the electron exchange capacity. The key role of graphitic structures in pyrogenic carbon in mediating EET was further evidenced by larger microbial electrolysis current with pyrogenic carbon prepared at higher pyrolysis temperatures. This study provides new insights into the electron transfer in the pyrogenic carbon-mediated microbial reduction of ferrihydrite.</p>

scholarly journals The Role of Shewanella oneidensis MR-1 Outer Surface Structures in Extracellular Electron Transfer

2010 ◽  
Vol 22 (7-8) ◽  
pp. 856-864 ◽  
Author(s):  
Rachida A. Bouhenni ◽  
Gary J. Vora ◽  
Justin C. Biffinger ◽  
Sheetal Shirodkar ◽  
Ken Brockman ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Outer Surface ◽  
Shewanella Oneidensis ◽  
Surface Structures ◽  
Extracellular Electron Transfer

scholarly journals Reversing an extracellular electron transfer pathway for electrode-driven NADH generation

2018 ◽  
Author(s):  
Nicholas M. Tefft ◽  
Michaela A. TerAvest
Keyword(s):  
Electron Transfer ◽  
Shewanella Oneidensis ◽  
Electrical Energy ◽  
Genetically Engineered ◽  
Extracellular Electron Transfer ◽  
Microbial Electrosynthesis ◽  
Electron Transfer Pathway ◽  
Background Strain ◽  
Nadh Dehydrogenases ◽  
Electron Sink

AbstractMicrobial electrosynthesis is an emerging technology with the potential to simultaneously store renewably generated energy, fix carbon dioxide, and produce high-value organic compounds. However, limited understanding of the route of electrons into the cell remains an obstacle to developing a robust microbial electrosynthesis platform. To address this challenge, we engineered an inward electron transfer pathway inShewanella oneidensisMR-1. The pathway uses native Mtr proteins to transfer electrons from an electrode to the inner membrane quinone pool. Subsequently, electrons are transferred from quinones to NAD+by native NADH dehydrogenases. This reverse functioning of NADH dehydrogenases is thermodynamically unfavorable, therefore we have added a light-driven proton pump (proteorhodopsin) to generate proton-motive force to drive this activity. Finally, we use reduction of acetoin to 2,3-butanediol via a heterologous butanediol dehydrogenase (Bdh) as an electron sink. Bdh is an NADH-dependent enzyme, therefore, observation of acetoin reduction supports our hypothesis that cathodic electrons are transferred to intracellular NAD+. Multiple lines of evidence indicate proper functioning of the engineered electrosynthesis system: electron flux from the cathode is influenced by both light and acetoin availability; and 2,3-butanediol production is highest when both light and a poised electrode are present. Using a hydrogenase-deficientS. oneidensisbackground strain resulted in a stronger correlation between electron transfer and 2,3-butanediol production, suggesting that hydrogen production is an off-target electron sink in the wild-type background. This system represents a promising genetically engineered microbial electrosynthesis platform and will enable a new focus on synthesis of specific compounds using electrical energy.

scholarly journals Protective Role of tolC in Efflux of the Electron Shuttle Anthraquinone-2,6-Disulfonate

2002 ◽  
Vol 184 (6) ◽  
pp. 1806-1810 ◽  
Author(s):  
J. Bruce H. Shyu ◽  
Douglas P. Lies ◽  
Dianne K. Newman
Keyword(s):  
Electron Transfer ◽  
Microbial Respiration ◽  
Critical Concentration ◽  
Shewanella Oneidensis ◽  
Protective Role ◽  
Extracellular Electron Transfer ◽  
Electron Shuttle ◽  
Functional Relationships ◽  
Electron Shuttles

ABSTRACT Extracellular electron transfer can play an important role in microbial respiration on insoluble minerals. The humic acid analog anthraquinone-2,6-disulfonate (AQDS) is commonly used as an electron shuttle during studies of extracellular electron transfer. Here we provide genetic evidence that AQDS enters Shewanella oneidensis strain MR-1 and causes cell death if it accumulates past a critical concentration. A tolC homolog protects the cell from toxicity by mediating the efflux of AQDS. Electron transfer to AQDS appears to be independent of the tolC pathway, however, and requires the outer membrane protein encoded by mtrB. We suggest that there may be structural and functional relationships between quinone-containing electron shuttles and antibiotics.

Identifying the potential extracellular electron transfer pathways from a c-type cytochrome network

2014 ◽  
Vol 10 (12) ◽  
pp. 3138-3146 ◽  
Author(s):  
De-Wu Ding ◽  
Jun Xu ◽  
Ling Li ◽  
Jian-Ming Xie ◽  
Xiao Sun
Keyword(s):  
Electron Transfer ◽  
Shewanella Oneidensis ◽  
Extracellular Electron Transfer ◽  
Genome Wide ◽  
A Genome ◽  
Electron Transfer Pathways

A genome-wide c-type cytochrome network was constructed to explore the extracellular electron transfer pathways in Shewanella oneidensis MR-1.

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