scholarly journals Cultivation of Exoelectrogenic Bacteria in Conductive DNA Nanocomposite Hydrogels Yields a Programmable Biohybrid Materials System

2019 ◽  
Author(s):  
Yong Hu ◽  
David Rehnlund ◽  
Edina Klein ◽  
Johannes Gescher ◽  
Christof M. Niemeyer
Keyword(s):  
Microbial Fuel Cells ◽  
Electrochemical Impedance ◽  
Shewanella Oneidensis ◽  
Extracellular Electron Transfer ◽  
Material System ◽  
Nanocomposite Hydrogels ◽  
The Matrix ◽  
Electrochemical Devices ◽  
Electron Transfer Pathways ◽  
Exoelectrogenic Bacteria

AbstractThe use of living microorganisms integrated within electrochemical devices is an expanding field of research, with applications in microbial fuel cells, microbial biosensors or bioreactors. We describe the use of porous nanocomposite materials prepared by DNA polymerization of carbon nanotubes (CNT) and silica nanoparticles (SiNP) for the construction of a programmable biohybrid system containing the exoelectrogenic bacterium Shewanella oneidensis. We initially demonstrate the electrical conductivity of the CNT-containing DNA composite by employment of chronopotentiometry, electrochemical impedance spectroscopy, and cyclic voltammetry. Cultivation of Shewanella oneidensis in these materials shows that the exoelectrogenic bacteria populate the matrix of the composite, while non-exoelectrogenic Escherichia coli remain on its surface. Moreover, the ability to use extracellular electron transfer pathways is positively correlated with number of cells within the conductive synthetic biofilm matrix. The Shewanella containing composite remains stable for several days. Programmability of this biohybrid material system is demonstrated by on-demand release and degradation induced by a short-term enzymatic stimulus. The perspectives of this approach for technical applications are being discussed.

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.

scholarly journals A novel growth and isolation medium for exoelectrogenic bacteria

2021 ◽  
Author(s):  
Zumaira Nazeer ◽  
Eustace Fernando
Keyword(s):  
Growth Medium ◽  
Solid Medium ◽  
Shewanella Oneidensis ◽  
Extracellular Electron Transfer ◽  
The Novel ◽  
Isolation Medium ◽  
Biochemical Characterisation ◽  
Electrochemically Active ◽  
Colour Changes ◽  
Exoelectrogenic Bacteria

A microbiological isolation and growth medium that can effectively discriminate electrochemically active exoelectrogenic bacteria from other non-exoelectrogenic bacteria, is currently unavailable. In this study, we developed a novel chromogenic growth and isolation solid medium based on MnO2 that can selectively allow the growth of exoelectrogenic bacteria and change the medium colour in the process. Known exoelectrogenic bacteria such as Shewanella oneidensis MR1 and other such bacteria from functional microbial fuel cell (MFC) anodes were capable of growing and changing colour in the novel growth medium. On the contrary, non-exoelectrogenic bacteria such as Escherichia coli ATCC 25922 were incapable of growing and inducing a colour changes in the novel medium. Further biochemical characterisation of these isolated exoelectrogenic bacteria by Raman micro-spectroscopy demonstrated that these bacteria over express cytochrome proteins that are vital in extracellular electron transfer events. This medium is a convenient method to isolate exoelectrogenic bacteria from complex environmental samples.

scholarly journals Enhancement of the Start-Up Time for Microliter-Scale Microbial Fuel Cells (µMFCs) via the Surface Modification of Gold Electrodes

Micromachines ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 703
Author(s):  
Begüm Şen-Doğan ◽  
Meltem Okan ◽  
Nilüfer Afşar-Erkal ◽  
Ebru Özgür ◽  
Özge Zorlu ◽  
...  
Keyword(s):  
Surface Modification ◽  
Fuel Cells ◽  
Microbial Fuel Cells ◽  
Microelectromechanical Systems ◽  
Electrochemical Impedance ◽  
Shewanella Oneidensis ◽  
Bacterial Attachment ◽  
Anode Surface ◽  
Sem Images ◽  
Start Up

Microbial Fuel Cells (MFCs) are biological fuel cells based on the oxidation of fuels by electrogenic bacteria to generate an electric current in electrochemical cells. There are several methods that can be employed to improve their performance. In this study, the effects of gold surface modification with different thiol molecules were investigated for their implementation as anode electrodes in micro-scale MFCs (µMFCs). Several double-chamber µMFCs with 10.4 µL anode and cathode chambers were fabricated using silicon-microelectromechanical systems (MEMS) fabrication technology. µMFC systems assembled with modified gold anodes were operated under anaerobic conditions with the continuous feeding of anolyte and catholyte to compare the effect of different thiol molecules on the biofilm formation of Shewanella oneidensis MR-1. Performances were evaluated using polarization curves, Electrochemical Impedance Spectroscopy (EIS), and Scanning Electron Microcopy (SEM). The results showed that µMFCs modified with thiol self-assembled monolayers (SAMs) (cysteamine and 11-MUA) resulted in more than a 50% reduction in start-up times due to better bacterial attachment on the anode surface. Both 11-MUA and cysteamine modifications resulted in dense biofilms, as observed in SEM images. The power output was found to be similar in cysteamine-modified and bare gold µMFCs. The power and current densities obtained in this study were comparable to those reported in similar studies in the literature.

Shewanella oneidensis MR-1 Msh pilin proteins are involved in extracellular electron transfer in microbial fuel cells

2012 ◽  
Vol 47 (1) ◽  
pp. 170-174 ◽  
Author(s):  
Lisa A. Fitzgerald ◽  
Emily R. Petersen ◽  
Richard I. Ray ◽  
Brenda J. Little ◽  
Candace J. Cooper ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Fuel Cells ◽  
Microbial Fuel Cells ◽  
Shewanella Oneidensis ◽  
Extracellular Electron Transfer

Mind the gap: cytochrome interactions reveal electron pathways across the periplasm of Shewanella oneidensis MR-1

2012 ◽  
Vol 449 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Bruno M. Fonseca ◽  
Catarina M. Paquete ◽  
Sónia E. Neto ◽  
Isabel Pacheco ◽  
Cláudio M. Soares ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Protein Interactions ◽  
Microbial Fuel Cells ◽  
Dissociation Constants ◽  
Shewanella Oneidensis ◽  
Extracellular Electron Transfer ◽  
Periplasmic Space ◽  
Protein Protein Interactions ◽  
Surface Charges ◽  
Kinetic Measurements

Extracellular electron transfer is the key metabolic trait that enables some bacteria to play a significant role in the biogeochemical cycling of metals and in bioelectrochemical devices such as microbial fuel cells. In Shewanella oneidensis MR-1, electrons generated in the cytoplasm by catabolic processes must cross the periplasmic space to reach terminal oxidoreductases found at the cell surface. Lack of knowledge on how these electrons flow across the periplasmic space is one of the unresolved issues related with extracellular electron transfer. Using NMR to probe protein–protein interactions, kinetic measurements of electron transfer and electrostatic calculations, we were able to identify protein partners and their docking sites, and determine the dissociation constants. The results showed that both STC (small tetrahaem cytochrome c) and FccA (flavocytochrome c) interact with their redox partners, CymA and MtrA, through a single haem, avoiding the establishment of stable redox complexes capable of spanning the periplasmic space. Furthermore, we verified that the most abundant periplasmic cytochromes STC, FccA and ScyA (monohaem cytochrome c5) do not interact with each other and this is likely to be the consequence of negative surface charges in these proteins. This reveals the co-existence of two non-mixing redox pathways that lead to extracellular electron transfer in S. oneidensis MR-1 established through transient protein interactions.

Molecular mechanisms regulating the catabolic and electrochemical activities of Shewanella oneidensis MR-1

2021 ◽  
Author(s):  
Atsushi Kouzuma
Keyword(s):  
Microbial Fuel Cells ◽  
Biofilm Formation ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Shewanella Oneidensis ◽  
Extracellular Electron Transfer ◽  
Cellular Functions ◽  
Regulatory Systems ◽  
Electrochemically Active ◽  
Recent Developments

Abstract Electrochemically active bacteria (EAB) interact electrochemically with electrodes via extracellular electron transfer (EET) pathways. These bacteria have attracted significant attention due to their utility in environment-friendly bioelectrochemical systems (BESs), e.g. microbial fuel cells and electrofermentation systems. The electrochemical activity of EAB is dependent on their carbon catabolism and respiration; thus, understanding how these processes are regulated will provide insights into the development of a more efficient BES. The process of biofilm formation by EAB on BES electrodes is also important for electric current generation, because it facilitates physical and electrochemical interactions between EAB cells and electrodes. This article summarizes the current knowledge on EET-related metabolic and cellular functions of a model EAB, Shewanella oneidensis MR-1, focusing specifically on regulatory systems for carbon catabolism, EET pathways, and biofilm formation. Based on recent developments, the author also discusses potential uses of engineered S. oneidensis strains for various biotechnological applications.

scholarly journals Tailored extracellular electron transfer pathways enhance the electroactivity of Escherichia coli

2021 ◽  
Author(s):  
Mohammed Mouhib ◽  
Melania Reggente ◽  
Lin Li ◽  
Nils Schuergers ◽  
Ardemis Anoush Boghossian
Keyword(s):  
Escherichia Coli ◽  
Electron Transfer ◽  
Shewanella Oneidensis ◽  
Electrical Current ◽  
Extracellular Electron Transfer ◽  
Organic Substrates ◽  
Transfer Rates ◽  
Electron Shuttling ◽  
E Coli ◽  
Electron Transfer Pathways

Extracellular electron transfer (EET) engineering in Escherichia coli holds great potential for bioremediation, energy and electrosynthesis applications fueled by readily available organic substrates. Due to its vast metabolic capabilities and availability of synthetic biology tools to adapt strains to specific applications, E. coli is of advantage over native exoelectrogens, but limited in electron transfer rates. We enhanced EET in engineered strains through systematic expression of electron transfer pathways differing in cytochrome composition, localization and origin. While a hybrid pathway harboring components of an E. coli nitrate reductase and the Mtr complex from the exoelectrogen Shewanella oneidensis MR-1 enhanced EET, the highest efficiency was achieved by implementing the complete Mtr pathway from S. oneidensis MR1 in E. coli. We show periplasmic electron shuttling through overexpression of a small tetraheme cytochrome to be central to the electroactivity of this strain, leading to enhanced degradation of the pollutant methyl orange and significantly increased electrical current to graphite electrodes.

scholarly journals Improving the extracellular electron transfer of Shewanella oneidensis MR-1 for enhanced bioelectricity production from biomass hydrolysate

RSC Advances ◽  
2017 ◽  
Vol 7 (48) ◽  
pp. 30488-30494 ◽  
Author(s):  
Yan-Zhai Wang ◽  
Yu Shen ◽  
Lu Gao ◽  
Zhi-Hong Liao ◽  
Jian-Zhong Sun ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Fuel Cells ◽  
Microbial Fuel Cells ◽  
Shewanella Oneidensis ◽  
Electricity Production ◽  
Extracellular Electron Transfer ◽  
Great Promise ◽  
Biomass Hydrolysate

Direct electricity production from biomass hydrolysate by microbial fuel cells (MFC) holds great promise for the development of the sustainable biomass industry.

scholarly journals Adaptive bidirectional extracellular electron transfer during accelerated microbiologically influenced corrosion of stainless steel

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Ziyu Li ◽  
Weiwei Chang ◽  
Tianyu Cui ◽  
Dake Xu ◽  
Dawei Zhang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Electron Transfer ◽  
Photoelectron Spectroscopy ◽  
Structural Damage ◽  
Electrochemical Impedance ◽  
Shewanella Oneidensis ◽  
Microbiologically Influenced Corrosion ◽  
Extracellular Electron Transfer ◽  
Bacterial Cells ◽  
Steel Electrode

AbstractMicrobiologically influenced corrosion of metals is prevalent in both natural and industrial environments, causing enormous structural damage and economic loss. Exactly how microbes influence corrosion remains controversial. Here, we show that the pitting corrosion of stainless steel is accelerated in the presence of Shewanella oneidensis MR-1 biofilm by extracellular electron transfer between the bacterial cells and the steel electrode, mediated by a riboflavin electron shuttle. From pitting measurements, X-ray photoelectron spectroscopy and Mott-Schottky analyses, the addition of an increased amount of riboflavin is found to induce a more defective passive film on the stainless steel. Electrochemical impedance spectroscopy reveals that enhanced bioanodic and biocathodic process can both promote the corrosion of the stainless steel. Using in situ scanning electrochemical microscopy, we observe that extracellular electron transfer between the bacterium and the stainless steel is bidirectional in nature and switchable depending on the passive or active state of the steel surface.

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