scholarly journals Nanotechnology to rescue bacterial bidirectional extracellular electron transfer in bioelectrochemical systems

RSC Advances ◽  
2016 ◽  
Vol 6 (36) ◽  
pp. 30582-30597 ◽  
Author(s):  
Shafeer Kalathil ◽  
Deepak Pant
Keyword(s):  
Electron Transfer ◽  
Electrode Materials ◽  
Extracellular Electron Transfer ◽  
Bioelectrochemical Systems ◽  
Nanostructured Electrode

Advanced nanostructured electrode materials largely improve the bacterial bidirectional extracellular electron transfer in bioelectrochemical systems.

Bacterial extracellular electron transfer in bioelectrochemical systems

2012 ◽  
Vol 47 (12) ◽  
pp. 1707-1714 ◽  
Author(s):  
Yonggang Yang ◽  
Meiying Xu ◽  
Jun Guo ◽  
Guoping Sun
Keyword(s):  
Electron Transfer ◽  
Extracellular Electron Transfer ◽  
Bioelectrochemical Systems

scholarly journals How thermophilic Gram-positive organisms perform extracellular electron transfer: characterization of the cell surface terminal reductase OcwA

2019 ◽  
Author(s):  
N.L. Costa ◽  
B. Hermann ◽  
V. Fourmond ◽  
M. Faustino ◽  
M. Teixeira ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Cell Surface ◽  
Electron Acceptors ◽  
Added Value ◽  
Extracellular Electron Transfer ◽  
Bioelectrochemical Systems ◽  
Positive Bacterium ◽  
Gram Positive ◽  
Evolutionary Pathway ◽  
Structural And Functional Properties

AbstractExtracellular electron transfer is the key process underpinning the development of bioelectrochemical systems for the production of energy or added-value compounds. Thermincola potens JR is a promising Gram-positive bacterium to be used in these systems because it is thermophilic. In this paper we describe the structural and functional properties of the nonaheme cytochrome OcwA, which is the terminal reductase of this organism. The structure of OcwA, determined at 2.2Å resolution shows that the overall-fold and organization of the hemes are not related to other metal reductases and instead are similar to that of multiheme cytochromes involved in the biogeochemical cycles of nitrogen and sulfur. We show that, in addition to solid electron acceptors, OcwA can also reduce soluble electron shuttles and oxyanions. These data reveal that OcwA can take the role of a respiratory ‘swiss-army knife’ allowing this organism to grow in environments with rapidly changing availability of terminal electron acceptors without the need for transcriptional regulation and protein synthesis.ImportanceThermophilic Gram-positive organisms were recently shown to be a promising class of organisms to be used in bioelectrochemical systems for the production of electrical energy. These organisms present a thick peptidoglycan layer that was thought to preclude them to perform extracellular electron transfer (i.e. exchange catabolic electrons with solid electron acceptors outside of the cell). In this manuscript we describe the structure and functional mechanisms of the multiheme cytochrome OcwA, the terminal reductase of the Gram-positive bacterium Thermincola potens JR found at the cell surface of this organism. The results presented here show that this protein is unrelated with terminal reductases found at the cell surface of other electroactive organisms. Instead, OcwA is similar to terminal reductases of soluble electron acceptors. Our data reveals that terminal oxidoreductases of soluble and insoluble substrates are evolutionarily related, providing novel insights into the evolutionary pathway of multiheme cytochromes.

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.

scholarly journals How Thermophilic Gram-Positive Organisms Perform Extracellular Electron Transfer: Characterization of the Cell Surface Terminal Reductase OcwA

mBio ◽  
2019 ◽  
Vol 10 (4) ◽  
Author(s):  
N. L. Costa ◽  
B. Hermann ◽  
V. Fourmond ◽  
M. M. Faustino ◽  
M. Teixeira ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Cell Surface ◽  
Electron Acceptors ◽  
Added Value ◽  
Extracellular Electron Transfer ◽  
Bioelectrochemical Systems ◽  
Positive Bacterium ◽  
Gram Positive ◽  
Evolutionary Pathway ◽  
Structural And Functional Properties

ABSTRACT Extracellular electron transfer is the key process underpinning the development of bioelectrochemical systems for the production of energy or added-value compounds. Thermincola potens JR is a promising Gram-positive bacterium to be used in these systems because it is thermophilic. In this paper, we describe the structural and functional properties of the nonaheme cytochrome OcwA, which is the terminal reductase of this organism. The structure of OcwA, determined at 2.2-Å resolution, shows that the overall fold and organization of the hemes are not related to other metal reductases and instead are similar to those of multiheme cytochromes involved in the biogeochemical cycles of nitrogen and sulfur. We show that, in addition to solid electron acceptors, OcwA can also reduce soluble electron shuttles and oxyanions. These data reveal that OcwA can work as a multipurpose respiratory enzyme allowing this organism to grow in environments with rapidly changing availability of terminal electron acceptors without the need for transcriptional regulation and protein synthesis. IMPORTANCE Thermophilic Gram-positive organisms were recently shown to be a promising class of organisms to be used in bioelectrochemical systems for the production of electrical energy. These organisms present a thick peptidoglycan layer that was thought to preclude them to perform extracellular electron transfer (i.e., exchange catabolic electrons with solid electron acceptors outside the cell). In this paper, we describe the structure and functional mechanisms of the multiheme cytochrome OcwA, the terminal reductase of the Gram-positive bacterium Thermincola potens JR found at the cell surface of this organism. The results presented here show that this protein can take the role of a respiratory “Swiss Army knife,” allowing this organism to grow in environments with soluble and insoluble substrates. Moreover, it is shown that it is unrelated to terminal reductases found at the cell surface of other electroactive organisms. Instead, OcwA is similar to terminal reductases of soluble electron acceptors. Our data reveal that terminal oxidoreductases of soluble and insoluble substrates are evolutionarily related, providing novel insights into the evolutionary pathway of multiheme cytochromes.

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

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