Saidjon Tavarov, Aleksandr Sidorov, Natalia Glotova

Electricity • 0

<jats:p>This article is devoted to the determination of the average daily electric load and the average electric load during the hours of maximum load, taking into account the generalized coefficient Ai, using data on electricity consumption for apartment buildings and individual residential buildings in Chelyabinsk and the cities of Dushanbe and Khorog in the Republic of Tajikistan. The results of modeling the average daily electric load, taking into account the developed generalized coefficient Ai, showed that the specific power values for apartments in apartment buildings and in individual residential buildings in the city of Chelyabinsk and the cities of Dushanbe and Khorog of the Republic of Tajikistan were overestimated, taking into account the applicability in the Republic of Tajikistan of the same standard values of specific electric loads (SELs) for apartments in apartment buildings (ABs) as in the Russian Federation. According to the results of modeling using data on the average monthly electricity consumption for 226 apartments in ABs and for individual residential buildings in Chelyabinsk, and according to the proposed approach, the average daily electric load on days during the month varied in the range of 2–3.5 kW/sq and below, while that for the cities of Dushanbe and Khorog of the Republic of Tajikistan varied in the range of 2–5 kW/sq and below, which did not exceed the SEL given by RB 256.1325800.2016. However, because of the lack of other energy sources (gas supply and hot water supply) in the conditions of the Republic of Tajikistan, on the basis of the obtained maximum load time factor and the generalized coefficient Ai(E), the obtained values of actual capacity exceeded the maximum during peak hours by 1.2–2.5 times the SEL given by RB 256.1325800.2016. To increase the durability and serviceability of power supplies and enhance the effectiveness of forecasting, the authors propose an approach based on the clustering of meteorological conditions, where each cluster has its own regression model. The decrease in mean absolute error due to clustering was 0.52 MW (57%). The use of meteorological conditions allowed the forecast error to be reduced by 0.22 MW (27%). High accuracy in electrical consumption forecasting leads to increased quality of power system management in general, including under such key indicators as reliability and serviceability.</jats:p>

Carlos Manchon, Fernando Muniesa‐Merino, María Llorente et al.

Microbial Biotechnology • 2023

<jats:title>Abstract</jats:title><jats:p>Purple phototrophic bacteria are one of the main actors in chemolithotrophic carbon fixation and, therefore, fundamental in the biogeochemical cycle. These microbes are capable of using insoluble electron donors such as ferrous minerals or even carbon‐based electrodes. Carbon fixation through extracellular electron uptake places purple phototrophic bacteria in the field of microbial electrosynthesis as key carbon capturing microorganisms. In this work we demonstrate biomass production dominated by purple phototrophic bacteria with a cathode (−0.6 V vs. Ag/AgCl) as electron donor. In addition, we compared the growth and microbial population structure with ferrous iron as the electron donor. We detect interaction between the cathode and the consortium showing a midpoint potential of 0.05 V (vs. Ag/AgCl). Microbial community analyses revealed different microbial communities depending on the electron donor, indicating different metabolic interactions. Electrochemical measurements together with population analyses point to <jats:italic>Rhodopseudomonas</jats:italic> genus as the key genus in the extracellular electron uptake. Furthermore, the genera <jats:italic>Azospira</jats:italic> and <jats:italic>Azospirillum</jats:italic> could play a role in the photoelectrotrophic consortium.</jats:p>

Mei Yao Yin, Xiao Juan Zhao, Chen Guang Li et al.

Advanced Materials Research • 0

<jats:p>Aiming at the problem of the traditional flue gas desulfurization and effluent disposal, two identical dual-chambered Microbial fuel cells (MFCs) are designed to remove man-made flue gas pre-treatment wastewater (FGPW). Glucose is used as the carbon source of the Sulfate reducing bacteria (SRB). Carbon cloth is used as the material of anodic and cathode. The treatment performance of flue gas pre-treatment wastewater and the possibility of electricity harvesting and sulfur recovery were investigated. The results show that the output voltage is 0.68-0.72V and the maximum current density is 28.12mA/m2 at pH=7.520. The concentration of sulfate measured with ion chromatography is decreased gradually during the operation of MFC. The elemental sulfur is found in carbon cloth (taken from the MFC after working for 58 days) by analysis with XPS. The results suggest that treatment of flue gas pre-treatment wastewater and electricity harvesting and sulfur recovery by MFC is technical feasibility.</jats:p>

R. J. V. Pulvertaft, C. G. Lemon

Journal of Hygiene • 1933

<jats:p>In this paper a short account is given of the application of photo-electric methods to bacteriology. Although such methods are now well established, and have been used in colorimetry and nephelometry for some years, they have not received the attention they deserve. The apparatus required, apart from the cell, will be found in any well-equipped laboratory; and their simplicity, as well as the elimination of personal errors, should assure the use of such methods in all experiments involving the measurement of colour intensity or turbidity of fluids.</jats:p>

Li Chun Wu, Chi Huang, Hsin Hui Wang et al.

Advanced Materials Research • 0

<jats:p>Microbial fuel cells, also known as biological fuel cells, use bacteria to convert biodegradable materials such as wastewater pollutants into electricity. However, limited studies revealed the high bioelectricity generation using a mediator-less MFC. This study isolated an exoelectrogen <jats:italic>E. faecium </jats:italic>YC 201, inoculated to a mediator-less MFC and obtained a high power density. Results show that the power generation reached a maximum of 121.3 ± 4.2 mW/m<jats:sup>2</jats:sup> that was higher than those of other similar MFCs reported in the past literature. Substrate types significantly affected electricity generation and the optimal substrate for electricity generation was glucose. The riboflavin was identified as possible mediator for the mediator-less MFC that was self-excreted by <jats:italic>E. faecium </jats:italic>YC 201. To our knowledge, this is the first time to clearly reveal the electricity characteristics of exoelectrogen <jats:italic>E. faecium </jats:italic>YC 210.</jats:p>

Seçil Ömeroğlu, F. Dilek Sanin

CLEAN – Soil, Air, Water • 2016

<jats:sec><jats:label /><jats:p>Today, the majority of the world's energy is provided by fossil fuels. Natural energy resources soon will be consumed as a result of rising energy needs of the growing population, leading to a global energy crisis. The insecurity in the energy market also affects the global economy negatively and forces the governments to investigate renewable energy alternatives such as bioenergy. Bioenergy technologies can reduce greenhouse gas (GHG) emissions significantly and can serve to satisfy many forms of energy demand. Microbial fuel cells (MFCs) are one of the bioenergy technologies converting the chemical energy in the bonds of organic wastes into electricity through the biocatalytic reactions of microorganisms. Since the microorganisms present in MFCs utilize organic matter while producing electricity, the use of wastewater and sewage sludge as substrate (fuel) makes MFCs not only a renewable energy technology but also a treatment alternative. Especially, considering the energy consumption of conventional wastewater and sludge treatment systems, MFCs offer a sustainable solution that supply the energy required while achieving high levels of treatment. In addition to these, MFCs can be used in sensors, biohydrogen production and bioremediation. However, the technologic and economic problems with MFCs limit their large scale applications. The purpose of this study is to analyze the recent studies on MFCs and evaluate the outstanding operational parameters and investigate the energy production and efficiency in MFCs fed with different types of wastewater sludge.</jats:p></jats:sec>

Asim Ali Yaqoob, Claudia Guerrero–Barajas, Mohamad Nasir Mohamad Ibrahim et al.

• 0

<jats:title>Abstract</jats:title> <jats:p>The present work focused on the utilization of three local wastes i.e., rambutan (<jats:italic>nephelium lappaceum</jats:italic>), langsat (<jats:italic>lansium parasiticum</jats:italic>) and mango (<jats:italic>mangifera indica</jats:italic>) wastes as organic substrates in benthic microbial fuel cell (BMFC) to reduce the cadmium and lead concentrations from synthetic wastewater. Out of the three wastes, the mango waste promoted a maximum current density (87.71 mA/m<jats:sup>2</jats:sup>) along with 78 % and 80 % removal efficiencies for Cd<jats:sup>2+</jats:sup> and Pb<jats:sup>2+</jats:sup>, respectively. The bacterial identification proved that <jats:italic>Klebsiella pneumoniae, Enterobacter</jats:italic>, and <jats:italic>Citrobacter</jats:italic> were responsible for metals removals and energy generation. Lastly, the BMFC mechanism, challenges and future recommendations are enclosed.</jats:p>

Iryna B. Rusyn, Кhrystyna R. Hamkalo

Acta Biologica Szegediensis • 0

<jats:p>The paper descibes the development of a biotechnological system for generating bioelectricity on closed balconies of buildings from living plants Alisma plantago-aquatica and soil microorganisms grown in containers with natural wetland substrate, provided with a graphite and Zn-galvanized steel electrode system. This biotechnology worked efficiently from the first days after installation and was practically at full capacity 2 weeks later. Electric power output was highest in the spring-summer and the early autumn period (at the time of the highest photosynthetic activity of plants). The highest current output was 58.6 mA at 10 Ω load. Bioelectricity generation by the biosystem was stable with slight fluctuations throughout the year in well-lighted and heated premises at a temperature of 21-26 °C, and the seasonal reduction of the bioelectricity level was 8.71%. On not-heated closed terraces and glazed balconies, with temperature fluctuations from 5 to 26 °C, the electricity production decreased in the winter period by 19.98% and 39.91% with and without adding of sulfate-reducing bacteria, respectively. The proposed system of electrodes for collection of bioelectric power is new, easy to manufacture and economical. It is resistant to waterlogged environment, and has good prospects for further improvements for more effective collection of plant-microbial bioelectricity. Maintainance of the biosystem is simple and accessible to everyone without special skills.</jats:p>

Hananeh Ahmadpanah, Ehsan Motamedian, Mohammad Mahdi Mardanpour

Scientific Reports • 0

<jats:title>Abstract</jats:title><jats:p><jats:italic>Zymomonas mobilis</jats:italic> (<jats:italic>Z. mobilis</jats:italic>), a bacterium known for its ethanol production capabilities, can also generate electricity by transitioning from ethanol production to electron generation. The purpose of this study is to investigate the ability of <jats:italic>Z. mobilis</jats:italic> to produce bioelectricity when utilized as a biocatalyst in a single-chamber microbial fuel cell (MFC). Given the bacterium's strong inclination towards ethanol production, a metabolic engineering strategy was devised to identify key reactions responsible for redirecting electrons from ethanol towards electricity generation. To evaluate the electroactivity of cultured <jats:italic>Z. mobilis</jats:italic> and its ethanol production in the presence of regulators, the reduction of soluble Fe(III) was utilized. Among the regulators tested, CuCl<jats:sub>2</jats:sub> demonstrated superior effectiveness. Consequently, the MFC was employed to analyze the electrochemical properties of <jats:italic>Z. mobilis</jats:italic> using both a minimal and modified medium. By modifying the bacterial medium, the maximum current and power density of the MFC fed with <jats:italic>Z. mobilis</jats:italic> increased by more than 5.8- and sixfold, respectively, compared to the minimal medium. These findings highlight the significant impact of metabolic redirection in enhancing the performance of MFCs. Furthermore, they establish <jats:italic>Z. mobilis</jats:italic> as an active electrogenesis microorganism capable of power generation in MFCs.</jats:p>

Kumar Gaurav

International Journal for Modern Trends in Science and Technology • 0

<jats:p>Current world is facing the twin crisis of energy security due to depletion of non renewable energy sources and climate change caused by green house effect. This has led the researchers to think for various alternatives for sustainable energy production. Fuel cell technology has emerged as one of the potential options for generating clean and efficient energy. Microbial fuel cell (MFC) is a device for the conversion of chemical energy stored in organic compounds into electrical energy with the help of different microorganisms. For practical application of MFC, the main factors that are considered are efficiency and low costs. Efficiency of MFC is dependent on the effectiveness of the anode and cathode materials used in the fuel cell. In this review paper, various developments in electrode materials for microbial fuel cells (MFC) are discussed. Various modifications of anode and cathode materials for enhancement of power generation and simultaneous waste water treatment are also explored.</jats:p>

Kenneth H. Nealson

Microbial Biotechnology • 2017

<jats:title>Summary</jats:title><jats:p>Electromicrobiology is the domain of those prokaryotes able to interact with charged electrodes, using them as electron donors and/or electron acceptors. This is performed via a process called extracellular electron transport, in which outer membrane cytochromes are used to oxidize and/or reduce otherwise unavailable insoluble electron acceptors. <jats:styled-content style="fixed-case">EET</jats:styled-content>‐capable bacteria can thus be used for a variety of purposes, ranging from small power sources, water reclamation, to pollution remediation and electrosynthesis. Because the study of <jats:styled-content style="fixed-case">EET</jats:styled-content>‐capable bacteria is in its nascent phase, the applications are mostly in developmental stages, but the potential for significant contributions to environmental quality is high and moving forward.</jats:p>

V. E. ROLFE, P. J. MILLA

Clinical Science • 1999

<jats:p>Nitric oxide stimulates intestinal ion transport via the activation of enteric nerves, but it is not known whether it regulates intestinal transport function by acting on the epithelium directly. The aim of this study was to determine the influence of nitric oxide on epithelial electrogenic ion secretion, measured as the short-circuit current (Isc), using the human colonic carcinoma cell line Caco-2. The cellular mechanisms were examined by measuring epithelial cGMP production, and nitrite release was monitored as an index of nitric oxide synthesized. The nitric oxide substrate L-arginine methyl ester increased nitrite release, electrogenic secretion and cell cGMP production. Pretreatment with L-NAME (Nω-nitro-L-arginine methyl ester, 1 mM), but not the D-isomer, significantly reduced the electrogenic secretion and cGMP production evoked by L-arginine methyl ester, implicating nitric oxide synthase involvement. Pretreatment with cystamine, but not Methylene Blue, significantly reduced the maximum Isc and the cGMP release induced by L-arginine methyl ester and the nitric oxide donor sodium nitroprusside, implicating the involvement of particulate guanylate cyclase. In conclusion, nitric oxide stimulates electrogenic ion secretion and cGMP production in intestinal epithelial cells by activating particulate guanylate cyclase. The direct action of nitric oxide on the intestinal epithelium may be important in the regulation of intestinal transport function in health and in inflammatory bowel disease.</jats:p>

Christine E. Bear, Connie N. Petrunka, Steven M. Strasberg

Hepatology • 1985

<jats:sec> <jats:title/> <jats:p>Chloride is the major inorganic anion in bile but its mechanism of passage from blood to bile is uncertain. Specific membrane channels account for most net inorganic anion flux in other cell types such as the proximal tubular cell and red blood cell; disulfonic stilbenes inhibit anion movement through these channels. Therefore, we have sought the presence of similar channels in the hepatocyte. Net inorganic anion flux or conductance was initiated in isolated rat hepatocytes by valinomycin in the presence of an outward potassium gradient. Potassium concentration in the extracellular medium increased from 2.75 ± 0.02 in control cell suspensions to 3.15 ± 0.04 in valinomycin–treated cell suspensions. Membrane potential difference (Em) (mV), determined as the distribution of [<jats:sup>14</jats:sup>C]tetraphenyl phosphonium ion was -28 mV in control cells and -42 mV in valinomycin–treated cells (p &lt; 0.05). Intracellular chloride concentration (<jats:sup>36</jats:sup>Cl<jats:sup>-</jats:sup>) (mEq per liter of cell water) decreased significantly from 38.6 in control cells to 32.0 in valinomycin–treated cells. The observed intracellular concentration (<jats:sup>36</jats:sup>Cl<jats:sup>-</jats:sup>) in both control and valinomycin–treated cell suspensions closely approximates values predicted on the basis of the Nernst equation: 41 and 29 (mEq per liter of cell water), respectively, suggesting that the chloride ion is passively distributed on the basis of the membrane potential difference. Furthermore, net rate–limited cell water loss of approximately 15% of control values was associated with the above valinomycin–stimulated changes in ion distribution, as assessed using three methods of cell water volume determination. 4,4′–Diisothiocyanostilbene–2,2′–disulfonate (DIDS), a specific inorganic anion channel blocker, inhibited the valinomycin–induced changes in chloride ion distribution; DIDS (0.8 m<jats:italic toggle="yes">M</jats:italic>–treated cells contained 45.2 ± 4.4 mEq per liter (<jats:sup>36</jats:sup>Cl<jats:sup>-</jats:sup>) following hyperpolarization with valinomycin whereas untreated cells contained 33.3 ± 4.8 mEq per liter of cell water after valinomycin treatment (p &lt; 0.05). Preincubation with DIDS (0.8 m<jats:italic toggle="yes">M</jats:italic>) also significantly suppressed valinomycin–induced changes in external K<jats:sup>+</jats:sup> concentration and cell water volume. These observations are consistent with the hypothesis that a channel exists for the electrogenic transport of chloride ion in isolated rat hepatocytes.</jats:p> </jats:sec>

Kuleshova T.E., Panova G.G., Gall N.R. et al.

Technical Physics Letters • 2022

<jats:p> The experimental bioelectrochemical current source based on the concentration gradient of charge carriers in the root environment of plants has been created. A potential difference of about 70 mV is observed in the nutrient solution. It is gradually decreasing due to equalization of concentrations. The voltage increases to 200 mV when plant are placed in a cultivation system as the root system develops due to the intensification of diffusion processes. The potential-forming role of nitrate forms of nitrogen is shown on the example of lettuce grown according to the panoponics technology. The separation of electrical charges by the root system during the life of plants can become an alternative source of green energy. Keywords: rhizosphere, bioelectric potential, panoponics, green energy. </jats:p>

Bruno KAESLER, Peter SCHÖNHEIT

European Journal of Biochemistry • 1989

<jats:p>Cell suspensions of <jats:italic>Methanosarcina barkeri</jats:italic> were found to oxidize formaldehyde to CO<jats:sub>2</jats:sub> and 2H<jats:sub>2</jats:sub> (Δ<jats:italic>G</jats:italic><jats:sup>0</jats:sup>′= ‐ 27 kJ/mol CO<jats:sub>2</jats:sub>), when methanogenesis was inhibited by 2‐bromoethanesulfonate. We report here that this reaction is coupled with (a) primary electrogenic Na<jats:sup>+</jats:sup> translocation at a stoichiometry of 2–3 Na<jats:sup>+</jats:sup>/CO<jats:sub>2</jats:sub>, (b) with secondary H<jats:sup>+</jats:sup> translocation via a Na<jats:sup>+</jats:sup>/H<jats:sup>+</jats:sup> antiporter and (c) with ATP synthesis driven by an electrochemical proton potential. This is concluded from the following findings.</jats:p><jats:p>Formaldehyde oxidation to CO<jats:sub>2</jats:sub> and 2H<jats:sub>2</jats:sub> was dependent on Na<jats:sup>+</jats:sup> ions, 2–3 mol Na<jats:sup>+</jats:sup>/mol formaldehyde oxidized were extruded. Na<jats:sup>+</jats:sup> translocation was inhibited by Na<jats:sup>+</jats:sup> ionophores, but not affected by protonophores or Na<jats:sup>+</jats:sup>/H<jats:sup>+</jats:sup> antiport inhibitors.</jats:p><jats:p>Formaldehyde oxidation was associated with the build up of a membrane potential in the order of 100 mV (inside negative), which could be dissipated by sodium ionophores rather than by protonophores.</jats:p><jats:p>Formaldehyde oxidation was coupled with ATP synthesis, which could be inhibited by Na<jats:sup>+</jats:sup> ionophores, Na<jats:sup>+</jats:sup>/H<jats:sup>+</jats:sup> antiport inhibitors, by protonophores and by the H<jats:sup>+</jats:sup> ‐translocating‐ATP‐synthase inhibitor, dicyclohexyl‐carbodiimide.</jats:p><jats:p>With cell suspensions of <jats:italic>Methanobacterium thermoautotrophicum</jats:italic> similar results were obtained.</jats:p>

Larisa Kiseleva, Justina Briliute, Irina V. Khilyas et al.

BioMed Research International • 2015

<jats:p>Some bacteria can carry out anaerobic respiration by depositing electrons on external materials, such as electrodes, thereby creating an electrical current. Into the anode chamber of microbial fuel cells (MFCs) having abiotic air-cathodes we inoculated microorganisms cultured from a magnetic particle-enriched portion of a marine tidal sediment, reasoning that since some external electron acceptors are ferromagnetic, electrogenic bacteria should be found in their vicinity. Two MFCs, one inoculated with a mixed bacterial culture and the other with an axenic culture of a helical bacterium isolated from the magnetic particle enrichment, termed strain HJ, were operated for 65 d. Both MFCs produced power, with production from the mixed culture MFC exceeding that of strain HJ. Strain HJ was identified as a<jats:italic>Thalassospira</jats:italic>sp. by transmission electron microscopic analysis and 16S rRNA gene comparisons. An MFC inoculated with strain HJ and operated in open circuit produced 47% and 57% of the maximal power produced from MFCs inoculated with the known electrogen<jats:italic>Geobacter daltonii</jats:italic>and the magnetotactic bacterium<jats:italic>Desulfamplus magnetomortis</jats:italic>, respectively. Further investigation will be needed to determine whether bacterial populations associated with magnetic particles within marine sediments are enriched for electrogens.</jats:p>

Magaly De La Cruz-Noriega, Santiago M. Benites, Segundo Rojas-Flores et al.

Sustainability • 0

<jats:p>Power generation and wastewater treatment are two great challenges for sustainable development. Microbial fuel cells (MFCs) are a sustainable alternative that can generate bioelectricity in the bioremediation process of wastewater. For this reason, the objective of this research was to generate bioelectricity through double-chamber microbial-combustion cell systems from wastewater from the Covicorti Wastewater Treatment Plant (PTARC) in the anodic chamber and electrogenic bacteria such as Stenotrophomonas maltophilia, Acinetobacter bereziniae, and Achromobacteria xylosoxidans in the cathode chamber, respectively. Measurements of the voltage, current, power density, current density, and optical density of the bacteria and biochemical oxygen demand (BOD) were made. In addition, a metagenomic analysis of the wastewater sample was performed. It was shown that the MFC with A. xylosoxidans generated the highest voltage peak (1.01 ± 0.06 V) on day 24, while the MFC with S. maltophilia generated the highest current value (0.71 ± 0.02 mA). The pH levels were slightly alkaline, and the maximum anodic conductivity value was presented by the MFC with A. cerevisiae, with a peak value of 81 ± 2 mS/cm on day 24. On the other hand, a maximum power density and current density of 195,493 ± 4717 mW/m2 and 4987 A/cm2, respectively, were obtained in the MFC with A. xylosoxidans. Finally, the metagenomic analysis identified the predominant phyla of Proteobacteria present in wastewater samples capable of generating electrical energy as Bacillota, Pseudomonadota, Bacteroidota, Actinomyketone, and Campylobacterota.</jats:p>

Peter Fromherz

Biosensors • 0

<jats:p>The concepts of transistor recording of electroactive cells are considered, when the response is determined by a current-induced voltage in the electrolyte due to cellular activity. The relationship to traditional transistor recording, with an interface-induced response due to interactions with the open gate oxide, is addressed. For the geometry of a cell-substrate junction, the theory of a planar core-coat conductor is described with a one-compartment approximation. The fast electrical relaxation of the junction and the slow change of ion concentrations are pointed out. On that basis, various recording situations are considered and documented by experiments. For voltage-gated ion channels under voltage clamp, the effects of a changing extracellular ion concentration and the enhancement/depletion of ion conductances in the adherent membrane are addressed. Inhomogeneous ion conductances are crucial for transistor recording of neuronal action potentials. For a propagating action potential, the effects of an axon-substrate junction and the surrounding volume conductor are distinguished. Finally, a receptor-transistor-sensor is described, where the inhomogeneity of a ligand–activated ion conductance is achieved by diffusion of the agonist and inactivation of the conductance. Problems with regard to a development of reliable biosensors are mentioned.</jats:p>

Seokheun Choi

Small • 2022

<jats:title>Abstract</jats:title><jats:p>Considerable research efforts into the promises of electrogenic bacteria and the commercial opportunities they present are attempting to identify potential feasible applications. Metabolic electrons from the bacteria enable electricity generation sufficient to power portable or small‐scale applications, while the quantifiable electric signal in a miniaturized device platform can be sensitive enough to monitor and respond to changes in environmental conditions. Nanomaterials produced by the electrogenic bacteria can offer an innovative bottom‐up biosynthetic approach to synergize bacterial electron transfer and create an effective coupling at the cell–electrode interface. Furthermore, electrogenic bacteria can revolutionize the field of bioelectronics by effectively interfacing electronics with microbes through extracellular electron transfer. Here, these new directions for the electrogenic bacteria and their recent integration with micro‐ and nanosystems are comprehensively discussed with specific attention toward distinct applications in the field of powering, sensing, and synthesizing. Furthermore, challenges of individual applications and strategies toward potential solutions are provided to offer valuable guidelines for practical implementation. Finally, the perspective and view on how the use of electrogenic bacteria can hold immeasurable promise for the development of future electronics and their applications are presented.</jats:p>

Ekramul Islam, Md Saddam Hossain, Palash Kumar Sarker et al.

Bangladesh Journal of Microbiology • 0

<jats:p>Electrogenic bacteria are able to transfer electrons to extracellular electron acceptors as well as can be used in devices like bioelectrochemical systems (BES). This study was focused to produce electricity from wastewater using microbial fuel cell and find out potential electrogenic bacteria from liquid tannery wastes. After power generation study, six isolates were screened as potential electrogenic bacteria. Of them, two potential bacteria were identified based on their morphological and biochemical characteristics and confirmed by phylogenetic analysis based on 16S rRNA gene sequence. We also investigated the effect of anode surface area on electricity generation in the microbial fuel cells and found that the surface area had positive impact on electricity generation.&#x0D; Bangladesh J Microbiol, Volume 37 Number 1 June 2020, pp 23-27</jats:p>

Ana Rumora, Liliana Hopkins, Kayla Yim et al.

BioTech • 0

<jats:p>Soil microbial fuel cells (SMFCs) are bioelectrical devices powered by the oxidation of organic and inorganic compounds due to microbial activity. Seven soils were randomly selected from Bergen Community College or areas nearby, located in the state of New Jersey, USA, were used to screen for the presence of electrogenic bacteria. SMFCs were incubated at 35–37 °C. Electricity generation and electrogenic bacteria were determined using an application developed for cellular phones. Of the seven samples, five generated electricity and enriched electrogenic bacteria. Average electrical output for the seven SMFCs was 155 microwatts with the start-up time ranging from 1 to 11 days. The highest output and electrogenic bacterial numbers were found with SMFC-B1 with 143 microwatts and 2.99 × 109 electrogenic bacteria after 15 days. Optimal electrical output and electrogenic bacterial numbers ranged from 1 to 21 days. Microbial DNA was extracted from the top and bottom of the anode of SMFC-B1 using the ZR Soil Microbe DNA MiniPrep Protocol followed by PCR amplification of 16S rRNA V3-V4 region. Next-generation sequencing of 16S rRNA genes generated an average of 58 k sequences. BLAST analysis of the anode bacterial community in SMFC-B1 demonstrated that the predominant bacterial phylum was Bacillota of the class Clostridia (50%). However, bacteria belonging to the phylum Pseudomonadota (15%) such as Magnetospirillum sp. and Methylocaldum gracile were also part of the predominant electrogenic bacterial community in the anode. Unidentified uncultured bacteria accounted for 35% of the predominant bacterial community. Bioelectrical devices such as MFCs provide sustainable and clean alternatives to future applications for electricity generation, waste treatment, and biosensors.</jats:p>

Matthew D. Yates, Roland D. Cusick, Ivan Ivanov et al.

Biotechnology and Bioengineering • 2014

<jats:title>ABSTRACT</jats:title><jats:sec><jats:label/><jats:p>Mesoporous structures can increase catalytic activity by maximizing the ratio of surface area to volume, but current synthesis techniques utilize expensive polymers and toxic chemicals. A <jats:italic>Geobacter sulfurreducens</jats:italic> biofilm was used as a sustainable template to form mesoporous Pd structures while eliminating the need for synthetic chemicals. The bulk of the biofilm material was removed by thermal treatments after nanoparticle formation, producing a catalytic Pd mesoporous (pore size 9.7 ± 0.1 nm) structure attached to the graphite electrode with a 1.5–2 µm thick backbone composed of nanoparticles (∼200 nm). A control electrode electrochemically plated with Pd in the absence of a biofilm exhibited a variable planar Pd base (∼0.5–3 µm thick) with sporadic Pd extrusions (∼2 µm across, 1–5 µm tall) from the surface. The biotemplated mesoporous structure produced 15–20% higher stable current densities during H<jats:sub>2</jats:sub> oxidation tests than the electrochemically plated control electrode, even though 30% less Pd was present in the biotemplated catalyst. These results indicate that electroactive biofilms can be used as a sustainable base material to produce nanoporous structures without the need for synthetic polymers. Biotechnol. Bioeng. 2014;111: 2349–2354. © 2014 Wiley Periodicals, Inc.</jats:p></jats:sec>

Maryam Rezaie, Zahra Rafiee, Seokheun Choi

Advanced Energy Materials • 2023

<jats:title>Abstract</jats:title><jats:p>Functioning ingestible capsules offer tremendous promise for a plethora of diagnostic and therapeutic applications. However, the absence of realistic and practical power solutions has greatly hindered the development of ingestible electronics. Microbial fuel cells (MFCs) hold great potential as power sources for such devices as the small intestinal environment maintains a steady internal temperature and a neutral pH. Those conditions and the constant supply of nutrient‐rich organics are a perfect environment to generate long‐lasting power. Although previous small‐scale MFCs have demonstrated many promising applications, little is known about the potential for generating power in the human gut environment. Here, this work reports the design and operation of a microbial biobattery capsule for ingestible applications. Dormant <jats:italic>Bacillus subtilis</jats:italic> endospores are a storable anodic biocatalyst that will provide on‐demand power when revived by nutrient‐rich intestinal fluids. A conductive, porous, poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate hydrogel anode enables superior electrical performance in what is the world's smallest MFC. Moreover, an oxygen‐rich cathode maintains its effective cathodic capability even in the oxygen‐deficit intestinal environment. As a proof‐of‐concept demonstration in stimulated intestinal fluid, the biobattery capsule produces a current density of 470 µA cm<jats:sup>−2</jats:sup> and a power density of 98 µW cm<jats:sup>−2</jats:sup>, ensuring its practical efficacy as a novel and sole power source for ingestible applications in the small intestine.</jats:p>

Pablo Alviz-Gazitua, Anna Espinoza-Tofalos, Francesca Formicola et al.

Environments • 0

<jats:p>Electroactive bacteria have a wide range of applications, including electricity production, bioremediation, and the sensing of toxic compounds. Bacterial biofilm formation is often mediated by the second messenger cyclic guanosine monophosphate (c-di-GMP) synthesized by a diguanylate cyclase (DGC). The role of c-di-GMP in the expression of c-type cytochromes has been previously reported. The aim of this study was to determine the bioelectrogenic activity of Cupriavidus metallidurans strain CH34 pJBpleD*, which possesses a constitutively active DGC that increases c-di-GMP levels. Notably, the heterologous expression of the constitutively active DGC in C. metallidurans strain CH34 pJBpleD* showed a higher biofilm formation and increased the electrical current production up to 560%. In addition, C. metallidurans CH34 pJBpleD* showed increased levels of c-type cytochrome-associated transcripts compared with the wild-type strain CH34. Scanning electron microscopies revealed a denser extracellular matrix with an increased exopolymeric substance content in the CH34 pJBpleD* biofilm on the electrode surface. The results of this study suggest that higher levels of c-di-GMP synthesized by a constitutively active diguanylate cyclase in C. metallidurans strain CH34 pJBpleD* activated the formation of an electroactive biofilm on the electrode, enhancing its exoelectrogenic activity.</jats:p>

Aaron Conrad Ericsson, Daniel John Davis, Craig Lawrence Franklin et al.

Physiological Genomics • 2015

<jats:p> Electrotaxis, directional cell movement in response to an electric potential, has been demonstrated in a wide range of cell types including lymphocytes. Exoelectrogens, microorganisms capable of generating electrical currents, have been identified in microbial fuel cells. However, no studies have investigated exoelectrogenic microbes in fresh feces or the effects of an exoelectrogenic microbiota on the host organism. Here we show that commensal gut microbial populations differ in their capacity for electrical current production by exoelectrogens and that those differences are predictive of increased lymphocyte trafficking to the gut in vivo, despite the lack of increased production of canonical lymphocyte-specific chemokines. Additionally, we demonstrate that the difference in current production between mice purchased from different commercial sources correlates reproducibly with the presence or absence of segmented filamentous bacteria, and while our data do not support a direct role for segmented filamentous bacteria in ex vivo current production, an exoelectrogenic microbiota can be transferred in vivo via mucosa-associated bacteria present in the ileum. Moreover, we detect upregulation of microbial genes associated with extracellular electron transfer in feces of mice colonized with exoelectrogenic microbiota containing segmented filamentous bacteria. While still correlative, these results suggest a novel means by which the gut microbiota modulates the recruitment of cells of the immune system to the gut. </jats:p>

Haikun Zhang, Xiaoke Hu

RSC Advances • 0

<p>Bioremediation of N-substituted aromatic compounds (NACs) has attracted a substantial amount of interest due to its cost effectiveness and environmental friendliness.</p>

Huan Deng, Hongjing Xue, Wenhui Zhong

Electroanalysis • 2017

<jats:title>Abstract</jats:title><jats:p>As a vast pool of micro‐organisms, soil might contain diverse exoelectrogenic bacteria. However, soil source exoelectrogenic bacteria were seldom studied. We isolated one exoelectrogenic bacterial strain (designated as R6) from a microbial fuel cell (MFC) operated with copper contaminated soil. Based on phylogenetic analysis of the 16S rRNA gene sequences, along with physiological and morphological characteristics, strain R6 was identified as <jats:italic>Clostridium sporogenes</jats:italic>, which was not reported as an exoelectrogenic bacterium before. Cyclic voltammetry measurements revealed that strain R6 transferred electrons to anode through direct contact rather than by generating electron shuttles. The voltage curve generated by strain R6 showed that the bacteria was resistant to 10 mg L<jats:sup>−1</jats:sup> Cu<jats:sup>2+</jats:sup>, but were inhibited with more than 25 mg L<jats:sup>−1</jats:sup> Cu<jats:sup>2+</jats:sup>. This study highlights the discovery of more soil source exoelectrogenic bacterial species.</jats:p>

A. C. Gonzalez-Aravena, K. Yunus, L. Zhang et al.

RSC Advances • 0

<p>Iron limited growth induces unprecedented rates of extracellular electron transport in cyanobacteria delivering enhanced photosynthesis driven bioelectricity in electrochemical platforms.</p>

Anna Prokhorova, Katrin Sturm-Richter, Andreas Doetsch et al.

Applied and Environmental Microbiology • 2017

<jats:title>ABSTRACT</jats:title> <jats:p> Anode-associated multispecies exoelectrogenic biofilms are essential for the function of bioelectrochemical systems (BESs). The individual activities of anode-associated organisms and physiological responses resulting from coculturing are often hard to assess due to the high microbial diversity in these systems. Therefore, we developed a model multispecies biofilm comprising three exoelectrogenic proteobacteria, <jats:named-content content-type="genus-species">Shewanella oneidensis</jats:named-content> , <jats:named-content content-type="genus-species">Geobacter sulfurreducens</jats:named-content> , and <jats:named-content content-type="genus-species">Geobacter metallireducens</jats:named-content> , with the aim to study in detail the biofilm formation dynamics, the interactions between the organisms, and the overall activity of an exoelectrogenic biofilm as a consequence of the applied anode potential. The experiments revealed that the organisms build a stable biofilm on an electrode surface that is rather resilient to changes in the redox potential of the anode. The community operated at maximum electron transfer rates at electrode potentials that were higher than 0.04 V versus a normal hydrogen electrode. Current densities decreased gradually with lower potentials and reached half-maximal values at −0.08 V. Transcriptomic results point toward a positive interaction among the individual strains. <jats:named-content content-type="genus-species">S. oneidensis</jats:named-content> and <jats:named-content content-type="genus-species">G. sulfurreducens</jats:named-content> upregulated their central metabolisms as a response to cultivation under mixed-species conditions. <jats:named-content content-type="genus-species">G. sulfurreducens</jats:named-content> was detected in the planktonic phase of the bioelectrochemical reactors in mixed-culture experiments but not when it was grown in the absence of the other two organisms. </jats:p> <jats:p> <jats:bold>IMPORTANCE</jats:bold> In many cases, multispecies communities can convert organic substrates into electric power more efficiently than axenic cultures, a phenomenon that remains unresolved. In this study, we aimed to elucidate the potential mutual effects of multispecies communities in bioelectrochemical systems to understand how microbes interact in the coculture anodic network and to improve the community's conversion efficiency for organic substrates into electrical energy. The results reveal positive interactions that might lead to accelerated electron transfer in mixed-species anode communities. The observations made within this model biofilm might be applicable to a variety of nonaxenic systems in the field. </jats:p>

K. W. Willman, R. Rocklin, R. Nowak et al.

Journal of the American Chemical Society • 1980

Abstract : Depending on silanization reaction conditions, aminophenylferrocene and tetrakis (p-aminophenyl) porphyrin can be covalently attached in monolayer or multi-molecular layer quantities to glassy carbon and superficially oxidized Pt electrodes using 4-(methyldichlorosily)butyryl chloride. This study applies various spectroscopies to surface structure of the attached porphyrin: XPS (number of surface amide bonds), fluorescence (quantity of porphyrin attached to a siloxane polymer film compared to quantity of electroactive porphyrin), and reflectance spectroscopies (spectroelectrochemical observation of oxidation state changes with electrode under potential control, including an electrochemically silent Co(III/II) porphyrin reaction). Electroactive films 500 monolayers thick can be prepared from the ferrocene by spin coating reactive silane; in aqueous sulfuric acid voltammetry of these films indicates a phase-like property. (Author)

Laura E. Barrosse-Antle, C. Hardacre, R. Compton

The Journal of Physical Chemistry B • 2009

The effects of such solutes such as halides and water on the physical properties of room temperature ionic liquids (RTILs) have been extensively studied. This work examines the effect of the solute carbon dioxide on the RTIL 1-ethyl-3-methylimidazolium bis(trifluoromethane-sulfonyl)imide ([C2mim][NTf2]) and its influence on the electrochemical characterization of the important redox couple ferrocene/ferrocenium (Fc/Fc+). The system was studied using cyclic voltammetry, chronoamperometry, and electron spin resonance (ESR) spectroscopy. Addition of 100% CO2 to a solution of Fc in [C2mim][NTf2] resulted in a substantial increase in both the limiting oxidative current and diffusion coefficient of Fc. Arrhenius plots of Fc diffusion coefficients in the pure and CO2-saturated ionic liquid revealed a decrease in activation energy of translational diffusion from 29.0 (+/- 0.5) kJ mol(-1) to 14.7 (+/- 1.6) kJ mol(-1), suggesting a reduction in the viscosity of the ionic liquid with addition of CO2. ESR spectroscopy was then used to calculate the rotational correlation coefficients of a probe molecule, 2,2,6,6-tetramethyl-1-piperinyloxyl (TEMPO), to add supporting evidence to this hypothesis. Arrhenius plots of rotational correlation coefficients in the pure and CO2-saturated ionic liquid resulted in a similar drop in activation energy from 28.7 (+/- 2.1) kJ mol(-1) to 18.2 (+/- 5.6) kJ mol(-1). The effect of this solute on the ionic liquid [C2mim][NTf2] and on the electrochemical measurements of the Fc/Fc+ couple emphasizes the necessity of fastidious sample preparation, as it is clear that the voltammetric currents of the electroactive species under study are influenced by the presence of CO2 in solution. The voltammetric response of the electroactive species in RTILs cannot be assumed to be independent of other solutes.

S. Daniele, M. Baldo, C. Bragato

Journal of the Brazilian Chemical Society • 2002

Mercury coated platinum microelectrodes were employed for the in situ determination, in soils and porewater of sediments, of redox key species of environmental interest. Sand samples were considered as soil model for the in situ detection of oxygen. Direct measurements of sulphide were performed in anoxic sediments collected in the Lagoon of Venice. An investigation on the interaction among heavy metals, sulphide and solid particles in pore-water extracted from the sediments was also performed. For the quantification of the various electroactive species examined, calibrantioless procedures were employed.

R. Martínez, M. Ramírez, I. González

Electroanalysis • 1998

The voltammetric characterization of ferrocene confined within a carbon paste electrode (CPE) with nonconducting binder (Nujol or silicon oil) was performed. The voltammetric behavior depends directly on the way in which the electroactive species were introduced into the paste: as a solid or previously dissolved into the binder. These two forms were found to contribute in the electrochemical process in a single voltammetric peak. Variations in the potential sweep rate, type of binder (meaning changes in ferrocene solubility), the amount of binder in the paste, and also the amount of the electroactive species affect the shape of the voltammetric curves obtained. This enables us to distinguish between the contributions of the solid and dissolved forms of ferrocene in the voltammetric response. From this study, it is established that the ferrocene oxidation in CPE was limited by diffusion, taking place in a layer beyond the electrode–electrolyte interface, resulting from the dissolution of ferrocene within the binder. The existing controversy reported for voltammetric studies of ferrocene in CPE could be explained by the presence of two different ferrocene species involved in the oxidation process.

Yu Ding, Changkun Zhang, Leyuan Zhang et al.

Chemical Society Reviews • 2018

With high scalability and independent control over energy and power, redox flow batteries (RFBs) stand out as an important large-scale energy storage system. However, the widespread application of conventional RFBs is limited by the uncompetitive performance, as well as the high cost and environmental concerns associated with the use of metal-based redox species. In consideration of advantageous features such as potentially low cost, vast molecular diversity, and highly tailorable properties, organic and organometallic molecules emerge as promising alternative electroactive species for building sustainable RFBs. This review presents a systematic molecular engineering scheme for designing these novel redox species. We provide detailed synthetic strategies for modifying the organic and organometallic redox species in terms of solubility, redox potential, and molecular size. Recent advances are then introduced covering the reaction mechanisms, specific functionalization methods, and electrochemical performances of redox species classified by their molecular structures. Finally, we conclude with an analysis of the current challenges and perspectives on future directions in this emerging research field.

Huaifang Zhang, Pei-luo Shi, Xiao Ma et al.

Advanced Energy Materials • 2022

Benefiting from ordered atomic structures and strong d‐orbital interactions, intermetallic compounds (IMCs) are promising electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Herein, the body‐centered cubic IrGa IMCs with atomic donor–acceptor architectures are synthesized and anchored on the nitrogen‐doped reduced graphene oxide (i.e., IrGa/N‐rGO). Structural characterizations and theoretical calculations reveal that the electron‐rich Ir sites are atomically dispersed in IrGa/N‐rGO, facilitating the electron transfer between Ir atoms and adsorbed species, which can efficiently decrease the energy barriers of the potential determining step for both HER and OER. Impressively, the IrGa/N‐rGO||IrGa/N‐rGO exhibits excellent performance for overall water splitting in alkaline medium, requiring a low cell voltage of 1.51 V to achieve 10 mA cm−2, meanwhile, exhibiting no significant degradation for 100 h. This work demonstrates that the rational design of noble metal electrocatalysts with donor–acceptor architectures is beneficial for catalytic reactions in energy conversion applications.

D. Zigah, Jean‐Marc Noël, C. Lagrost et al.

The Journal of Physical Chemistry C • 2010

Electron transfers in modified polyaryl multilayers containing redox active molecules (ferrocenyl moieties) have been investigated by scanning electrochemical microscopy (SECM) in feedback mode. The modified surfaces were prepared by the electro-reduction of aryl diazonium salts that provides anchoring layers for the immobilization of the electroactive groups. Two types of anchoring films were prepared, the first with aminophenyl and the second with phenylcarboxylic acid groups, allowing us to vary the oxidation level of the electroactive film. Determination of the apparent electron transfer rates between the modified surface and a series of redox mediators displaying increasing standard potentials permits the analysis of different processes involved in the charge transfer, namely, the permeation of the organic molecules (the mediator) and the conduction mechanism. In addition to the first oxidation of the immobilized molecules by the mediator at the solution−film interface, the global oxidation kinetics ...

Julien Sarmet, F. Leroux, C. Taviot‐Gueho et al.

Molecules • 2023

By selecting two electroactive species immobilized in a layered double hydroxide backbone (LDH) host, one able to act as a positive electrode material and the other as a negative one, it was possible to match their capacity to design an innovative energy storage device. Each electrode material is based on electroactive species, riboflavin phosphate (RF) on one side and ferrocene carboxylate (FCm) on the other, both interleaved into a layered double hydroxide (LDH) host structure to avoid any possible molecule migration and instability. The intercalation of the electroactive guest molecules is demonstrated by X-ray diffraction with the observation of an interlayer LDH spacing of about 2 nm in each case. When successfully hosted into LDH interlayer space, the electrochemical behavior of each hybrid assembly was scrutinized separately in aqueous electrolyte to characterize the redox reaction occurring upon cycling and found to be a rapid faradic type. Both electrode materials were placed face to face to achieve a new aqueous battery (16C rate) that provides a first cycle-capacity of about 7 mAh per gram of working electrode material LDH/FCm at 10 mV/s over a voltage window of 2.2 V in 1M sodium acetate, thus validating the hybrid LDH host approach on both electrode materials even if the cyclability of the assembly has not yet been met.

S. Branagan, N. M. Contento, P. Bohn

Journal of the American Chemical Society • 2012

Electroosmotic flow (EOF) is used to enhance the delivery of Fe(CN)(6)(4-)/Fe(CN)(6)(3-) to an annular nanoband electrode embedded in a nanocapillary array membrane, as a route to high efficiency electrochemical conversions. Multilayer Au/polymer/Au/polymer membranes are perforated with 10(2)-10(3) cylindrical nanochannels by focused ion beam (FIB) milling and subsequently sandwiched between two axially separated microchannels, producing a structure in which transport and electron transfer reactions are tightly coupled. The middle Au layer, which contacts the fluid only at the center of each nanochannel, serves as a working electrode to form an array of embedded annular nanoband electrodes (EANEs), at which sufficient overpotential drives highly efficient electrochemical processes. Simultaneously, the electric field established between the EANE and the QRE (>10(3) V cm(-1)) drives electro-osmotic flow (EOF) in the nanochannels, improving reagent delivery rate. EOF is found to enhance the steady-state current by >10× over a comparable structure without convective transport. Similarly, the conversion efficiency is improved by approximately 10-fold compared to a comparable microfluidic structure. Experimental data agree with finite element simulations, further illustrating the unique electrochemical and transport behavior of these nanoscale embedded electrode arrays. Optimizing the present structure may be useful for combinatorial processing of on-chip sample delivery with electrochemical conversion; a proof of concept experiment, involving the generation of dissolved hydrogen in situ via electrolysis, is described.

E. Fell, Diana De Porcellinis, Yan Jing et al.

Journal of The Electrochemical Society • 2023

We assess the suitability of potassium ferri-/ferrocyanide as an electroactive species for long-term utilization in aqueous organic redox flow batteries. A series of electrochemical and chemical characterization experiments was performed to distinguish between structural decomposition and apparent capacity fade of ferri-/ferrocyanide solutions used in the capacity-limiting side of a flow battery. Our results indicate that, in contrast with previous reports, no structural decomposition of ferri-/ferrocyanide occurs at tested pH values as high as 14 in the dark or in diffuse indoor light. Instead, an apparent capacity fade takes place due to a chemical reduction of ferricyanide to ferrocyanide, via chemical oxygen evolution reaction. We find that this parasitic process can be further exacerbated by carbon electrodes, with apparent capacity fade rates at pH 14 increasing with an increased ratio of carbon electrode surface area to ferricyanide in solution. Based on these results, we report a set of operating conditions that enables the long-duration cycling of alkaline ferri-/ferrocyanide electrolytes and demonstrate how apparent capacity fade rates can be engineered by the initial system setup. If protected from direct exposure to light, the structural stability of ferri-/ferrocyanide anions allows for their practical deployment as electroactive species in long duration energy storage applications.

Ai Sugitani, Takeshi Watanabe, T. Ivandini et al.

Phys. Chem. Chem. Phys. • 2013

Selective anodic stripping voltammetry of trace metal ions in a mixture solution with another interfering metal was developed based on Fick's law concerning the diffusion profile of interfering metals at the electrode surface after electrolysis treatment. A boron-doped diamond film was used as the sensing electrode, while a perforated carbon sheet was used for the interference-depleting electrode. The influence of the electrode distance and the time of electrolysis on the formation of the diffusion profile was studied. As a working model, the detection of cadmium with copper interference was investigated. The advantage of the method in comparison to general electrolysis was also discussed. The method offers a new perspective for improving the selective detection of metal ions by analyzing the diffusion profiles of the interfering species at the surface of electrodes.