Electrochemical communication between microbial cells and electrodes via osmium redox systems

2012 ◽  
Vol 40 (6) ◽  
pp. 1330-1335 ◽  
Author(s):  
Kamrul Hasan ◽  
Sunil A. Patil ◽  
Dónal Leech ◽  
Cecilia Hägerhäll ◽  
Lo Gorton
Keyword(s):  
Electron Transfer ◽  
Biofuel Cells ◽  
Major Group ◽  
Electrochemical Biosensors ◽  
Bioelectrochemical Systems ◽  
Bacterial Cells ◽  
Redox Systems ◽  
Microbial Cells ◽  
Fundamental Part ◽  
Micro Organisms

Electrochemical communication between micro-organisms and electrodes is the integral and fundamental part of BESs (bioelectrochemical systems). The immobilization of bacterial cells on the electrode and ensuring efficient electron transfer to the electrode via a mediator are decisive features of mediated electrochemical biosensors. Notably, mediator-based systems are essential to extract electrons from the non-exoelectrogens, a major group of microbes in Nature. The advantage of using polymeric mediators over diffusible mediators led to the design of osmium redox polymers. Their successful use in enzyme-based biosensors and BFCs (biofuel cells) paved the way for exploring their use in microbial BESs. The present mini-review focuses on osmium-bound redox systems used to date in microbial BESs and their role in shuttling electrons from viable microbial cells to electrodes.

Mtr extracellular electron-transfer pathways in Fe(III)-reducing or Fe(II)-oxidizing bacteria: a genomic perspective

2012 ◽  
Vol 40 (6) ◽  
pp. 1261-1267 ◽  
Author(s):  
Liang Shi ◽  
Kevin M. Rosso ◽  
John M. Zachara ◽  
James K. Fredrickson
Keyword(s):  
Electron Transfer ◽  
Cell Envelope ◽  
Shewanella Oneidensis ◽  
Extracellular Electron Transfer ◽  
Bacterial Cells ◽  
Electron Transfer Pathway ◽  
Protein Components ◽  
Micro Organisms ◽  
Reducing Bacteria ◽  
Mediate Electron Transfer

Originally discovered in the dissimilatory metal-reducing bacterium Shewanella oneidensis MR-1 (MR-1), key components of the Mtr (i.e. metal-reducing) pathway exist in all strains of metal-reducing Shewanella characterized. The protein components identified to date for the Mtr pathway of MR-1 include four multihaem c-Cyts (c-type cytochromes), CymA, MtrA, MtrC and OmcA, and a porin-like outer membrane protein MtrB. They are strategically positioned along the width of the MR-1 cell envelope to mediate electron transfer from the quinone/quinol pool in the inner membrane to Fe(III)-containing minerals external to the bacterial cells. A survey of microbial genomes has identified homologues of the Mtr pathway in other dissimilatory Fe(III)-reducing bacteria, including Aeromonas hydrophila, Ferrimonas balearica and Rhodoferax ferrireducens, and in the Fe(II)-oxidizing bacteria Dechloromonas aromatica RCB, Gallionella capsiferriformans ES-2 and Sideroxydans lithotrophicus ES-1. The apparent widespread distribution of Mtr pathways in both Fe(III)-reducing and Fe(II)-oxidizing bacteria suggests a bidirectional electron transfer role, and emphasizes the importance of this type of extracellular electron-transfer pathway in microbial redox transformation of iron. The organizational and electron-transfer characteristics of the Mtr pathways may be shared by other pathways used by micro-organisms for exchanging electrons with their extracellular environments.

scholarly journals Status Update on Bioelectrochemical Systems: Prospects for Carbon Electrode Design and Scale-Up

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 278
Author(s):  
Katharina Herkendell
Keyword(s):  
Gradual Increase ◽  
Scale Up ◽  
Value Added ◽  
Biofuel Cells ◽  
Carbon Electrode ◽  
Electrode Design ◽  
Bioelectrochemical Systems ◽  
Electrode Assemblies ◽  
The Stability ◽  
Scientific Attention

Bioelectrochemical systems (BES) employ enzymes, subcellular structures or whole electroactive microorganisms as biocatalysts for energy conversion purposes, such as the electrosynthesis of value-added chemicals and power generation in biofuel cells. From a bioelectrode engineering viewpoint, customizable nanostructured carbonaceous matrices have recently received considerable scientific attention as promising electrode supports due to their unique properties attractive to bioelectronics devices. This review demonstrates the latest advances in the application of nano- and micro-structured carbon electrode assemblies in BES. Specifically, in view of the gradual increase in the commercial applicability of these systems, we aim to address the stability and scalability of different BES designs and to highlight their potential roles in a circular bioeconomy.

scholarly journals Strain- and Substrate-Dependent Redox Mediator and Electricity Production by Pseudomonas aeruginosa

2016 ◽  
Vol 82 (16) ◽  
pp. 5026-5038 ◽  
Author(s):  
Erick M. Bosire ◽  
Lars M. Blank ◽  
Miriam A. Rosenbaum
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Electron Transfer ◽  
Fuel Cells ◽  
Microbial Fuel Cells ◽  
Pure Culture ◽  
Bioelectrochemical Systems ◽  
Content Type ◽  
Mediated Electron Transfer ◽  
Phenazine Production ◽  
Model Strain

ABSTRACTPseudomonas aeruginosais an important, thriving member of microbial communities of microbial bioelectrochemical systems (BES) through the production of versatile phenazine redox mediators. Pure culture experiments with a model strain revealed synergistic interactions ofP. aeruginosawith fermenting microorganisms whereby the synergism was mediated through the shared fermentation product 2,3-butanediol. Our work here shows that the behavior and efficiency ofP. aeruginosain mediated current production is strongly dependent on the strain ofP. aeruginosa. We compared levels of phenazine production by the previously investigated model strainP. aeruginosaPA14, the alternative model strainP. aeruginosaPAO1, and the BES isolatePseudomonassp. strain KRP1 with glucose and the fermentation products 2,3-butanediol and ethanol as carbon substrates. We found significant differences in substrate-dependent phenazine production and resulting anodic current generation for the three strains, with the BES isolate KRP1 being overall the best current producer and showing the highest electrochemical activity with glucose as a substrate (19 μA cm−2with ∼150 μg ml−1phenazine carboxylic acid as a redox mediator). Surprisingly,P. aeruginosaPAO1 showed very low phenazine production and electrochemical activity under all tested conditions.IMPORTANCEMicrobial fuel cells and other microbial bioelectrochemical systems hold great promise for environmental technologies such as wastewater treatment and bioremediation. While there is much emphasis on the development of materials and devices to realize such systems, the investigation and a deeper understanding of the underlying microbiology and ecology are lagging behind. Physiological investigations focus on microorganisms exhibiting direct electron transfer in pure culture systems. Meanwhile, mediated electron transfer with natural redox compounds produced by, for example,Pseudomonas aeruginosamight enable an entire microbial community to access a solid electrode as an alternative electron acceptor. To better understand the ecological relationships between mediator producers and mediator utilizers, we here present a comparison of the phenazine-dependent electroactivities of threePseudomonasstrains. This work forms the foundation for more complex coculture investigations of mediated electron transfer in microbial fuel cells.

Hydrothermal Generation of 3-Dimensional WO3 Nanocubes, Nanobars and Nanobricks, Their Antimicrobial and Anticancer Properties

2021 ◽  
Vol 21 (10) ◽  
pp. 5337-5343
Author(s):  
Nilam Qureshi ◽  
Seungjae Lee ◽  
Ravindra Chaudhari ◽  
Pramod Mane ◽  
Jayant Pawar ◽  
...  
Keyword(s):  
Chemical Characterization ◽  
Growth Curves ◽  
Viable Cell ◽  
Inhibition Zone ◽  
Bacterial Cells ◽  
Hydrothermal Route ◽  
3 Dimensional ◽  
Anticancer Properties ◽  
Bacteria And Fungi ◽  
Micro Organisms

In our current endeavor, 3-dimensional (3D) tungsten oxide (WO3) nanostructures (nanocubes, nanobars and nanobricks) have been swiftly generated via hydrothermal route at 160 °C for 24 h. Physico-chemical characterization of the resultant powder revealed formation of WO3 nanostructures with predominantly faceted cube, brick and rectangular bar-like morphology. The present study was also aimed at exploring the antimicrobial and anticancer potential of WO3 nanostructures. Antimicrobial activity was tested against different micro-organisms viz., Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli and Aspergillus fumigatus. The antibacterial and antifungal activity was ascertained against these micro-organisms by measuring the diameter of inhibition zone in agar well diffusion test which revealed that the resultant WO3 nanostructures acted as excellent antibacterial agents against both bacteria and fungi but were more effective against the fungus, A. fumigatus. To examine the growth curves of bacterial cells, time kill assay was monitored for E. coli, against which significant antibacterial action of WO3 nanostructures was noted. The anti-cancer activity of WO3 nanostructures was found to be concentration-dependent against KB cell line by viable cell count method. In our pilot study, WO3 nanostructures suspension with concentration in the range of 10−1 to 10−5 mg/ml was found to kill KB cells effectively.

Materials for Mediator-Free Electron Transfer in the Enzymatic Electrodes of Biobatteries and Biofuel Cells

2013 ◽  
Vol 45 (11) ◽  
pp. 1-8 ◽  
Author(s):  
K. Zelechowska ◽  
K. Stolarczyk ◽  
D. Lyp ◽  
J. F. Biernat ◽  
J. Rogalski ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Free Electron ◽  
Biofuel Cells

scholarly journals Nanocatalysts Containing Direct Electron Transfer-Capable Oxidoreductases: Recent Advances and Applications

Catalysts ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 9 ◽  
Author(s):  
Dalius Ratautas ◽  
Marius Dagys
Keyword(s):  
Electron Transfer ◽  
State Of The Art ◽  
Direct Electron Transfer ◽  
Biofuel Cells ◽  
Solid Surfaces ◽  
Electron Mediator ◽  
Research Directions ◽  
Catalytic Systems ◽  
Nanoparticle Catalysts ◽  
Nanoparticle Surface

Direct electron transfer (DET)-capable oxidoreductases are enzymes that have the ability to transfer/receive electrons directly to/from solid surfaces or nanomaterials, bypassing the need for an additional electron mediator. More than 100 enzymes are known to be capable of working in DET conditions; however, to this day, DET-capable enzymes have been mainly used in designing biofuel cells and biosensors. The rapid advance in (semi) conductive nanomaterial development provided new possibilities to create enzyme-nanoparticle catalysts utilizing properties of DET-capable enzymes and demonstrating catalytic processes never observed before. Briefly, such nanocatalysts combine several cathodic and anodic catalysis performing oxidoreductases into a single nanoparticle surface. Hereby, to the best of our knowledge, we present the first review concerning such nanocatalytic systems involving DET-capable oxidoreductases. We outlook the contemporary applications of DET-capable enzymes, present a principle of operation of nanocatalysts based on DET-capable oxidoreductases, provide a review of state-of-the-art (nano) catalytic systems that have been demonstrated using DET-capable oxidoreductases, and highlight common strategies and challenges that are usually associated with those type catalytic systems. Finally, we end this paper with the concluding discussion, where we present future perspectives and possible research directions.

Development of Biofuel Cell Using a Complex of Highly Oriented Immobilized His-Tagged Enzyme and Carbon Nanotube Surface Through a Pyrene Derivative

2019 ◽  
Vol 19 (6) ◽  
pp. 3551-3557 ◽  
Author(s):  
Hiroaki Sakamoto ◽  
Ayako Koto ◽  
Ei-Ichiro Takamura ◽  
Hitoshi Asakawa ◽  
Takeshi Fukuma ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Carbon Nanotube ◽  
Glucose Dehydrogenase ◽  
Molecular Layer ◽  
Biofuel Cells ◽  
Biofuel Cell ◽  
Similar Process ◽  
Enzyme Complex ◽  
Catalytic Current ◽  
Oriented Immobilization

For increasing the output of biofuel cells, increasing the cooperation between enzyme reaction and electron transfer on the electrode surface is essential. Highly oriented immobilization of enzymes onto a carbon nanotube (CNT) with a large specific surface area and excellent conductivity would increase the potential for their application as biosensors and biofuel cells, by utilizing the electron transfer between the electrode-molecular layer. In this study, we prepared a CNT-enzyme complex with highly oriented immobilization of enzyme onto the CNT surface. The complex showed excellent electrical characteristics, and could be used to develop biodevices that enable efficient electron transfer. Multi-walled carbon nanotubes (MWCNT) were dispersed by pyrene butyric acid N-hydroxysuccinimide ester, and then N-(5-amino-1-carboxypentyl) iminodiacetic acid (AB-NTA) and NiCl2 were added to modify the NTA-Ni2+ complex on the CNT surface. Pyrroloquinoline quinone (PQQ)-dependent glucose dehydrogenase (GDH) was immobilized on the CNT surface through a genetically introduced His-tag. Formation of the MWCNT-enzyme complex was confirmed by monitoring the catalytic current electrochemically to indicate the enzymatic activity. PQQ-GDH was also immobilized onto a highly ordered pyrolytic graphite surface using a similar process, and the enzyme monolayer was visualized by atomic force microscopy to confirm its structural properties. A biofuel cell was constructed using the prepared CNT-enzyme complex and output evaluation was carried out. As a result, an output of 32 μW/cm2 could be obtained without mediators.

A technique for the study of oxygen availability to micro-organisms in soil and its possible use as an index of soil aeration

1947 ◽  
Vol 37 (3) ◽  
pp. 249-256 ◽  
Author(s):  
D. M. Webley
Keyword(s):  
Oxygen Uptake ◽  
Oxygen Availability ◽  
Bacterial Cells ◽  
Experimental Conditions ◽  
Soil Aeration ◽  
Resultant Effect ◽  
Aeration Conditions ◽  
A New Technique ◽  
Micro Organisms ◽  
Properties Of Soil

1. In Part I of the paper details are presented of a new technique for the study of oxygen availability to bacteria added to soil. In essentials the technique consists of adding a washed suspension of bacterial cells together with excess of suitable oxidizable substrate to air dried, sieved soil contained in Warburg vessels. The rate of oxygen uptake is looked upon as a function of the aeration conditions within the soil. The results can be expressed by means of a conventional figure called the aeration factor (or A.F.).2. In Part II with the use of the technique it has been shown that two physical properties of soil which influence oxygen availability under the experimental conditions of the technique are (a) moisture content of the soil, (b) the amount of break-up of the soil crumbs. Since the A.F. measures the resultant effect produced by these factors it may be regarded as an index of soil aeration.

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