Adrian L. Talamantes, Alex Blomfield

Natural Gas & Electricity • 2015

In a major step toward the implementation of a modern and competitive wholesale electricity market in Mexico (the “Wholesale Market”), on September 8, 2015, the Secretaría de Energía (SENER) published the first set of regulations establishing the Wholesale Market's design and operating principles, and governing the marketing of electricity, ancillary services, renewable energy certificates (RECs), installed capacity, and congestion revenue rights (collectively, the “Market Protocols”). SENER intends to publish practice manuals and operating guidelines by the end of 2015 to instruct market participants and further implement the Wholesale Market. 1

Jeff D. Makholm

Natural Gas & Electricity • 2017

Electricity markets have problems. In the August 2017 edition of this newsletter, I wrote about “Electricity Deregulation Under Siege,” where various regulators, from the United Kingdom to New York, have proposed restrictions on retail power supply competition. In December 2016, I wrote about how the intersection of gas and electricity systems causes its own problems in power markets around the world.

Natural Gas & Electricity • 2017

Current market measures show generally good news for end‐users in prices, increases in natural gas and renewables, and decreases in coal and nuclear.

Benjamin Schlesinger

Natural Gas & Electricity • 2016

As an energy form, natural gas enjoys unique cost and environmental advantages—it's free of sulfur, particulates, and most other air contaminants; is plentiful at low prices; and emits the least carbon of any carbon fuel.

Thomas Russo

Natural Gas & Electricity • 2018

Back in May 2015, I presented a paper 1 in Houston on the resilience of natural gas and oil pipelines and their relationship to the power sector. The audience was polite, but few people were interested in resilience. How things have changed!

Zoran Marinšek, Sašo Brus, Gerhard Meindl

Electricity • 2024

The current formal common denominator of the electricity supply system in Europe has been the Harmonized Electricity Market Role Model (HEMRM) set up by ENTSO-E, ebIX, and EFET at the turn of the millennium; it introduced the concept of de-coupling and the vertical structuring of the system into the previously vertically integrated system. Since then, within demonstration projects, the system has been undergoing further changes in a controlled environment, generating bottom-up energy, caused by new technologies, business models, and new players, and extending the concept of the system to the level of energy communities and prosumers. Therefore, this paper proposes a coherent approach to the extension of HEMRM to the lowest levels in both the grid and market segments—full harmonization. This entails further structuring of both segments downwards and applying the principles of vertically nested subsystems—a system of systems approach—to a unit functional level of the electricity system, which can be the prosumer itself. At the lowest levels, the de-coupled system becomes coupled; additionally, it cross-sects with other energy vectors. Complete harmonization reduces the number of system and market segments and represents system standardization, leading to both subsystem and system-wide optimization. Prerequisites for it include the automated trading of flexibilities by the prosumers and implicit trading of energy transfer capacities along the distribution grids. The energy reservoirs, implicit and explicit, short-term, and long-term, play a vital role in techno-economic balancing.

Dimitrios Kontogiannis, Dimitrios Bargiotas, Aspassia Daskalopulu et al.

Electricity • 2022

Accurate electricity demand forecasting is vital to the development and evolution of smart grids as well as the reinforcement of demand side management strategies in the energy sector. Since this forecasting task requires the efficient processing of load profiles extracted from smart meters for large sets of clients, the challenges of high dimensionality often lead to the adoption of cluster-based aggregation strategies, resulting in scalable estimation models that operate on aggregate times series formed by client groups that share similar load characteristics. However, it is evident that the clustered time series exhibit different patterns that may not be processed efficiently by a single estimator or a fixed hybrid structure. Therefore, ensemble learning methods could provide an additional layer of model fusion, enabling the resulting estimator to adapt to the input series and yield better performance. In this work, we propose an adaptive ensemble member selection approach for stacking and voting regressors in the cluster-based aggregate forecasting framework that focuses on the examination of forecasting performance on peak and non-peak observations for the development of structurally flexible estimators for each cluster. The resulting ensemble models yield better overall performance when compared to the standalone estimators and our experiments indicate that member selection strategies focusing on the influence of non-peak performance lead to more performant ensemble models in this framework.

Jeff D. Makholm

Natural Gas & Electricity • 2017

My late colleague and friend Alfred Kahn relayed how President Jimmy Carter hired him in 1977 to head the Civil Aeronautics Board to reform and ultimately deregulate the US airline industry. Accepting the job, he told a group of airline executives (to their fury), “I really don't know one plane from the other. To me they are all marginal costs with wings.” He used that term to signal his intention of reforming the industry in keeping with economic principles, uninfluenced by the romance of air travel.

Alfredo Abarca, Yuri Percy Molina Rodriguez, Cristhian Ganvini

Electricity • 2025

This research evaluates the economic feasibility of implementing smart metering (SM) systems in Peruvian electricity distribution companies, prioritizing the maximization of the benefit–cost ratio (BCR). Seven communication architectures were analyzed in four companies, considering variables such as energy losses, meter costs, and per capita consumption. The results, evaluated through economic indicators such as the net present value, internal rate of return (IRR), and BCR showed that Luz Del Sur (LDS) obtained the best results, while ADINELSA (an electrical infrastructure management company), Sociedad Eléctrica Sur Oeste (SEAL), and Electro Sur Este (ELSE) presented the worst. The combination of power line communication and general packet radio service was the most viable architecture, followed by radio frequency mesh. However, this study concludes that a massive deployment of SM in Peru is not yet economically viable because of low per capita consumption and high meter costs. Future research should consider the benefits of distributed generation and demand management, as well as evaluate new communication technologies.

Amal S. Othman, Nashwa A. Ahmed, Mona S. Elneklawi et al.

Microbial Cell Factories • 2023

Abstract Microbial fuel cell (MFC) is a bio-electrical energy generator that uses respiring microbes to transform organic matter present in sludge into electrical energy. The primary goal of this work was to introduce a new approach to the green electricity generation technology. In this context a total of 6 bacterial isolates were recovered from sludge samples collected from El-Sheikh Zayed water purification plant, Egypt, and screened for their electrogenic potential. The most promising isolates were identified according to 16S rRNA sequencing as Escherichia coli and Enterobacter cloacae , promising results were achieved on using them in consortium at optimized values of pH (7.5), temperature (30°C) and substrate (glucose/pyruvate 1%). Low level red laser (λ = 632.8nm, 8mW) was utilized to promote the electrogenic efficiency of the bacterial consortium, maximum growth was attained at 210 sec exposure interval. In an application of adding standard inoculum (10 7 cfu/mL) of the photo-stimulated bacterial consortium to sludge based MFC a significant increase in the output potential difference values were recorded, the electricity generation was maintained by regular supply of external substrate. These results demonstrate the future development of the dual role of MFCs in renewable energy production and sludge recycling.

, Andreas Coester

• 2023

The industrial activities that our modern civilization depends upon have increased CO2 and other greenhouse gas emissions significantly. There is considerable consensus that this increase in emissions has been contributing to climate change. In order to limit global warming, a comprehensive and fast transition to lower emissions in all industrial sectors is crucial. Despite the strong increase in renewable energies capacity over the past years, there are various challenges associated with the further transition to a 100% renewable energies supply. One of the challenges is the fluctuating supply of renewable energies due to the intermitted nature of wind and sunshine. Another challenge arises from the low marginal costs of renewable energies that lead to a reduction of the electricity price, which impairs a profitable operation of both conventional and renewable energies power plants. Against this backdrop, the main question of this research is which policy scenario can ensure an economic efficient and ongoing expansion of renewable energies together with a secure level of electricity supply? The research focusses on Germany, as Germany has to find sustainable and economically feasible policy scenarios in the short-term due to its strong expansion of renewable energies and its decision to phase-out both nuclear and coal power plants.

Chinwendu Jude Echejiuba, Chimezie Jason Ogugbue, Ifeyinwa Sarah Obuekwe

Studia Universitatis Babes-Bolyai Biologia • 2025

Azo dyes are prevalent anthropogenic compounds, making their enhanced treatment crucial in our color-saturated world. This study examined the ability of a microbial consortium, comprising Pseudomonas aeruginosa (MW584979), Enterobacter hormaechei (MW584986), Providencia stuartii (MW584987), Escherichia coli (MZ394117), and Pseudomonas xiamenensis (MW585052), to decolorize Sudan orange G in a microbial fuel cell (MFC) after determining the optimal conditions for dye decoorization using response surface methodology (RSM) and the One Factor at a Time (OFAT) method. Degradation products were analyzed using the gas chromatography-mass spectroscopy technique. The consortium achieved an 88% decolorization rate within 24 hours under the optimal conditions identified by the Central Composite Design (CCD) of RSM. These conditions, pH 7.0, temperature 35, salinity 5 g/L, and glucose concentration 10 g/L, when applied in the MFC, resulted in an enhanced decolorization rate of 92% and simultaneous electricity generation of 130 mV within 24 hours. GC-MS analysis confirmed the breakdown of the azo dye into simpler, less toxic compounds. Metabolites produced through RSM and MFC processes were identified and compared with controls using chromatography-mass spectrometry. Degradation metabolites obtained after treatment of the dye wastewater in the MFC include Cyclopentane and cyclopropylidene-2(1H)-naphthalenone which highlights the role of microbial enzymatic activity in converting complex azo dye structures into environmentally benign compounds. These results highlight the successful integration of RSM for process optimization and MFCs for enhanced biodegradation and renewable energy production. The scalability of this technique is promising, given the relatively simple and cost-effective setup of MFC systems. Moreover, the economic feasibility of large-scale deployment is enhanced by the dual benefits of wastewater treatment and renewable energy production, making it a sustainable solution for managing azo dye pollution. Article history: Received 7 August 2024; Revised 3 December 2024;Accepted 22 May 2025; Available online 25 June 2025

Damilola Adebayo

African Studies • 2025

Africa has the lowest electricity access rate in the world today. About six hundred million of its estimated 1.4 billion population (or 43 percent) are still waiting to experience reliable electricity supply, according to a recent estimate. Yet, unlike other forms of Western technological inventions, such as in communications (telegraph or the telephone) or rail transportation, historians have demonstrated that the infrastructure of large-scale electricity production made its way to Africa not long after it was developed in Europe and the United States. Electricity became a tool for modern life during the late 1870s through the work of scientists, notably Thomas Edison, who invented the incandescent bulb. By 1882, the mining city of Kimberly in South Africa had become the first African municipal area to have electric lights. Kimberly’s coal-fired central power station was also the second in the world (after Pearl Street Station, New York). Ethiopia reportedly had its first electricity generator, powered by diesel, as a gift from the German government to the emperor in the 1890s; while in Nigeria, electricity supply commenced in Lagos in 1898. In nearly all of Africa, the electrification timeline was intertwined with European colonialism. The main sites of electricity consumption during the years before the Second World War were the mines and cities where the European and African political and economic elite resided. As a result, the motives of colonial investments have been debated among scholars, and the main issues have ranged from economic exploitation to racial discrimination. The 1940s was the era of colonial development, and electricity began to gain increasing prominence in the industrial policy deliberations within the colonies. As African states approached independence, nationalists also imagined hydroelectric dams as indispensable for economic growth. Despite the optimism and grand strategies of the 1950s and 1960s, Africa’s electricity consumption per capita remains the lowest rate of any world region. African governments and international financial institutions have invested billions to increase supply capacity. However, allegations of public-sector corruption and mismanagement are prevalent. The national grid frequently collapses, load shedding is endemic, and millions of Africans often fall back on small generators. Global dialogues on climate change have also spurned an interest in exploring green alternatives, particularly solar energy, as the future of electrification in Africa.

Rachchanon Yodrach, Purita Rattanabundan, Pimprapa Chaijak

Journal of Degraded and Mining Lands Management • 2025

Mature coconut water (MCW) is a by-product of various coconut industries. It is produced in large quantities annually. If untreated, this waste can pollute groundwater systems upon discharge. In this study, MCW was used as a low-cost medium for bacterial nanocellulose (BNC) production. The effects of exogenous carbon and nitrogen sources were studied under static conditions. Suitable conditions were then selected for use in a microbial fuel cell (MFC) to generate electrical energy from BNC fermentation. Subsequently, the BNC was immobilized with silver nanoparticles (AgNPs) and used against the pathogenic bacteria Escherichia coli and Staphylococcus aureus. The results showed that the system generated maximum current density (CD) and power density (PD) of 54.250 ± 0.180 mA/m² and 5.886 ± 0.039 mW/m², respectively. The AgNPs-immobilized BNC film effectively inhibited the growth of both Gram-negative E. coli and Gram-positive S. aureus with inhibition zones measuring 26.0 ± 0.3 mm and 30.1 ± 0.2 mm, respectively. This study provides new insights into producing electrical energy during BNC synthesis fermentation.

Guendouz Dif, Atika Meklat, Abdelghani Zitouni

Basic and Applied Sciences - Scientific Journal of King Faisal University • 2023

This study aimed to analyze the whole genome of the bacterial strain PL, isolated from pond sediment, to evaluate its genetic characteristics in the degradation of waste and toxic substrates and the generation of bioelectricity. This was compared to the type strain of the bacterial species Geobacter sulfurreducens (G. sulfurreducens) (PCA) and the strain KN400. Genomic taxonomy on the TYGS platform established the affiliation of strain PL with the bacterial species G. sulfurreducens. Subsequently, a genomic study of strains PL, PCA, and KN400 was performed using various bioinformatics tools. These included the study of genes associated with functional categories (COG) through genome annotation using the RAST server, followed by gene identification using the Prokka program to discover and identify genes related to electricity production. The results of the genomic analysis of the PL strain showed that it possesses many genes necessary for generating electric current. These included genes related to the formation of thick biofilms, adhesion to the anode of microbial fuel cells (MFCs), oxidation of various substrates and environmental pollutants, and extracellular electron transfer. Overall, the obtained results indicate that the PL strain is a promising candidate for sustainable bioenergy generation. KEYWORDS bioinformatics tools, genomic analysis, geobacter sulfurreducens, MFCs, sustainable bioenergy, whole genome

Uday Sriram L, Siva Naga Raju, Chandram Karri

International Journal of Applied Power Engineering (IJAPE) • 2021

<p class="Title1">In this article, bacterial foraging optimization (BFO) algorithm is developed for single side optimal bidding strategy in an electricity market. Optimal bidding strategy is one of the important functions in the electricity market along with forecasting of the electricity price and the profit based unit commitment. The prime objective of generating company (Genco) is to maximize their profit when they participate in the bidding process. The BFO algorithm has been used to maximize the probability density function (pdf). In the second stage the BFO algorithm is again applied to maximize the profit of the suppliers. The Proposed algorithm is developed in MATLAB (Version, 2019) and tested on standard test case available in the literature. Also, the simulation results are presented and compared. It is noticed that the proposed method yields the best results in terms of profit.</p>

Raihanir Rafila Sessa, Fuji Astuti Febria

European Journal of Applied Sciences • 2025

Rubber wastewater contains many organic compounds that can pollute the environment if directly released. Likewise, paddy field mud also contains many organic compounds that can be utilized with rubber wastewater as an electricity producer through the process of breaking down organic compounds by microorganisms to produce electrons using the microbial fuel cell method. Microbial fuel cell will generate electricity while reducing waste load. This study was conducted to determine the potential of rubber wastewater and paddy field mud in the production of electricity through the process of degradation of organic matter by microorganisms. The treatment was done by combining rubber wastewater and paddy field mud with the ratio of 1:1, 1:2, and 1:3. The results showed that the highest voltage production by rubber wastewater was 228.1 mV and by paddy field mud was 27.4 mV. In the treatment, the highest voltage was 75.3 mV at a ratio of 1:1. There was also a decrease in waste load in the form of COD, BOD, TAN, TSS, and pH. The isolation results on the MFC anode found 6 isolates, namely Citrobacter sp.1, Citrobacter sp.2, Citrobacter sp.3, Citrobacter sp.4, Clostridium sp., and Bacillus sp. It can be concluded in this research that rubber wastewater and paddy field mud have the potential to produce electrical energy through microbial fuel cell. It is hoped that optimization in further research on electricity production will be useful as an environmentally friendly renewable energy.

Tri Mulyono, Misto Misto, Busroni Busroni et al.

International Journal of Renewable Energy Development • 2020

In this experiment, seven single-chamber microbial fuel cells (MFCs) were made and filled with various types of local agricultural soil and sediments found in irrigation channels, which were mixed with glucose and green bean sprouts mashed as nutrients for microbial survival. MFC electric power was measured every day for 35 days. Every time low electric power indicated weak microbial activity, green bean sprouts were added. The highest electric power of 118 µW (23.4 mW/m2) was observed in fuel cells filled with agricultural land planted with rice. Power density reached the range of 120–140 mW/m2, whereas the incubation time showed a maximum of 35 days. This study found that adding green bean sprouts can increase the length of the MFC cycle and strengthen the generated power up to 122 mW. ©2020. CBIORE-IJRED. All rights reserved

T. Leser, A. Baker

Beneficial Microbes • 2023

Abstract Bifidobacterium adolescentis is one of the most abundant bifidobacterial species in the human large intestine, and is prevalent in 60-80% of healthy human adults with cell densities ranging from 10 9 -10 10 cells/g of faeces. Lower abundance is found in children and in elderly individuals. The species is evolutionary adapted to fermenting plant-derived glycans and is equipped with an extensive sugar transporter and degradation enzymes repertoire. Consequently, the species is strongly affected by dietary carbohydrates and is able to utilize a wide range of prebiotic molecules. B. adolescentis is specialized in metabolizing resistant starch and is considered a primary starch degrader enabling growth of other beneficial bacteria by cross-feeding. The major metabolic output is acetate and lactate in a ratio of 3:2. Several health-beneficial properties have been demonstrated in certain strains of B. adolescentis in vitro and in rodent models, including enhancement of the intestinal barrier function, anti-inflammatory and immune-regulatory effects, and the production of neurotransmitters (GABA), and vitamins. Although causalities have not been established, reduced abundance of B. adolescentis as part of a dysbiotic colonic microbiota in human observational studies has been associated with inflammatory bowel diseases, irritable bowel syndrome, coeliac disease, cystic fibrosis, Helicobacter pylori infection, type 1 and 2 diabetes, metabolic syndrome, nonalcoholic steatohepatitis, and certain allergies. It is therefore reasonable to conceive B. adolescentis as a health-associated, or even health-promoting bacterial species in humans.

B.J. Yogesh, S. Bharathi

Industrial Applications of Soil Microbes • 2022

This chapter deals with the significance of soil microbes from an industrial perspective. Soil microbes are the most diverse populations to exist on earth, and they are known to have played a prominent role in the development of soil chemistry, soil texture, and soil suitability to sustain plant life. The chapter deals with the significance of cultural techniques for the isolation of desired microbial strains from the soil. The importance of screening techniques for isolates is emphasized, wherein the potential strains are tested for their physiological characteristics that are industrially beneficial. A few criteria are mentioned for judging the soil isolate’s capability to become an industrial strain. The difference between natural isolates and potential industrial strains is discussed. Useful strains are categorized based on their ability to produce primary and secondary metabolites with commercial applications in terms of economic, agricultural, and environmental significance. Industrially important microbes are listed with emphasis on the types of metabolites they produce and their applications. Knowledge of metabolic pathways involved in metabolite production and their regulation in terms of various feedback control systems are discussed. Strain improvement and its role in improving industrial aspects of microbes are highlighted. Bacillus sp. are given their due importance as the most diverse and dynamic forms of bacteria, contributing immensely to our knowledge and being the most beneficial forms of soil microbes. A few metabolites are discussed in detail, with emphasis given to enzymes, microbial polymers, amino acids, solvents, organic acids, and antibiotics. Microbial bioleaching mostly employs bacteria that could help in the recovery of metals from low-grade ores, and industries based on biomining have shown a renewed interest in this economically viable process.

Mary M Maleckar, Pablo Martín-Vasallo, Wayne R Giles et al.

Research Square • 2020

Abstract Background: Although the chondrocyte is a non-excitable cell, there is strong interest in gaining detailed knowledge of its ion pumps, channels, exchangers and transporters. In combination, these transport mechanisms set the resting potential, regulate cell volume and strongly modulate responses of the chondrocyte to endocrine agents and physicochemical alterations in the surrounding extracellular micro-environment.Materials and Methods: Mathematical modeling was used to assess the functional roles of energy-requiring active transport, the Na + /K + pump, in chondrocytes.Results: Our findings illustrate plausible physiological roles for the Na + /K + pump in regulating the resting membrane potential and suggest ways in which specific molecular components of pump can respond to the unique electrochemical environment of the chondrocyte.Conclusion: This analysis provides a basis for linking chondrocyte electrophysiology to metabolism and yields insights into novel ways of manipulating or regulating responsiveness to external stimuli both under baseline conditions and in chronic diseases such as osteoarthritis (OA).

Sheldon Cotts, Bijentimala Keisham, Vikas Berry

ECS Meeting Abstracts • 2020

A synergistic, nanoscale electrical-interface with the membranes of exoelectrogenic microbes will have transformative impact on biological cell based electronic-devices. In this presentation, we will report a conformal graphenic interface on biocatalytic Geobacter sulfurreducens membrane that results in quantum-capacitance induced n-doping in graphene. This further enhances electron shuttling from the membrane to improve electron harvesting from the electrogenic membrane. The quantum coupling of reduced graphene oxide (rGO) with the connected protein-membrane channels leads to an additional electron density of 3.44 x 10 12 cm -2 and an increase in the in-plane phonon vibration energies (G) of rGO by 5 cm -1 . This n-doping enhances the electron transfer-rate from the cell membrane into the rGO improving the power density of a simplistic microbial fuel cell (MFC) by ~ 2 folds. The synergistic electron-harvesting and conformal membrane-interfacing of flexible 2D nanomaterials can lead to an evolution in the design of microbe-circuitry to power stand-alone nanodevices. Figure 1

Lei Zhou, Tuoxian Tang, Dandan Deng et al.

bioRxiv (Cold Spring Harbor Laboratory) • 2023

Abstract Electricigens decompose organic matter and convert stored chemical energy into electrical energy through extracellular electron transfer. They serve as significant biocatalysts for microbial fuel cells which have practical applications in green energy generation, effluent treatment, and bioremediation. A facultative anaerobic electrogenic strain SQ-1 is isolated from sludge in a biotechnology factory. The strain SQ-1 is a close relative of Klebsiella variicola . Multilayered biofilms form on the surface of a carbon electrode after the isolated bacteria are inoculated into a microbial fuel cell device. This strain produces high current densities of 625 μA cm -2 by using acetate as the carbon source in a three-electrode configuration. The electricity generation performance is also analyzed in a dual-chamber microbial fuel cell. It reaches a maximum power density of 560 mW m -2 when the corresponding output voltage is 0.59 V. The facultative strain SQ-1 utilizes hydrous ferric oxide as an electron acceptor to perform extracellular electricigenic respiration in anaerobic conditions. Since facultative strains possess better properties than anaerobic strains, Klebsiella sp. SQ-1 may be a promising exoelectrogenic strain for applications in microbial electrochemistry.

Charles Didier, Julia Orrico, Omar Cepeda Torres et al.

Research Square • 2022

Abstract Benchtop tissue cultures have become increasingly complex in recent years, as more “on-a-chip” biological technologies such as Microphysiological Systems (MPSs) work to incorporate cellular constructs that more accurately represent their respective biological systems. Such MPSs have begun providing major breakthroughs in biological research and are poised to shape the field in the coming decades. These biological systems necessitate integrated sensing modalities to procure complex, multiplexed datasets, with unprecedented combinatorial biological detail. In this work we expand on our polymer-metal biosensor approach by demonstrating a facile technology towards compound biosensing which are characterized through custom modeling approaches. Herein we develop a compound chip with 3D microelectrodes, 3D microfluidics, Interdigitated Electrodes (IDEs) and a micro-heater. The chip is subsequently tested using electrical/electrochemical characterization of 3D microelectrodes with 1kHz impedance and phase recordings, and IDE-based high frequency (~ 1MHz frequencies) impedimetric analysis of differential localized temperature recordings, both of which are modelled through equivalent electrical circuits for process parameter extraction. Additionally, a simplified antibody-conjugation strategy was employed for a similar IDE-based analysis of the implications for a key analyte (L-Glutamine) binding on the equivalent electrical circuit. Lastly, acute microfluidic perfusion modelling was performed to demonstrate ease of microfluidics integration into such a polymer-metal biosensor platform for potential complimentary localized chemical stimulation. Combined, our work demonstrates the design, development, and characterization of an accessibly designed, polymer-metal compound biosensor for electrogenic cellular constructs, geared towards comprehensive MPS data collection.

Arda Gülay, Greg Fournier, Barth F. Smets et al.

bioRxiv (Cold Spring Harbor Laboratory) • 2022

SUMMARY Oxygen availability is critical for microbes as some are obligatorily dependent on oxygen for energy conservation. However, aerobic microbes that live in environments with varying oxygen concentrations experience pressures over evolutionary time, selecting alternative energy metabolisms that relax the dependence on oxygen. One such capacity is extracellular electron transfer (or EET), which is the ability to transfer electrons from central metabolism to extracellular oxidants such as iron and manganese oxides. We posit that the β- proteobacterial ammonia-oxidizing bacteria, highly specialized lineages heretofore recognized as strict aerobes, can be capable of EET as they have been constantly observed in oxygen-limiting and depleted environments. Here, we show that a strictly aerobic ammonia-oxidizer, Nitrosomonas communis , utilized a poised electrode to maintain metabolic activity in anoxic conditions. The presence and activity of multi-heme cytochromes suggested that direct electron transfer is the mechanism underlying EET. Molecular clock models suggest that the ancestors of β- proteobacterial ammonia oxidizers appeared after the oxygenation of Earth when the oxygen levels were >10 -4 p O 2 (PAL), suggesting their aerobic origins. Phylogenetic reconciliations of gene and species trees show that the multi-heme c-type EET proteins in Nitrosomonas and Nitrosospira were acquired by gene transfer from β- proteobacteria during oxygen scarcity. The preservation of EET metabolism over billions of years under fluctuating oxygen levels and aspects of EET physiology in β- proteobacterial ammonia oxidizers might explain how they have been coped with oxygen stress and survived under oxygen deprivation. SIGNIFICANCE Metabolic versatility can permit typically aerobic microbes to survive in anaerobic conditions when oxygen is deficient as a terminal electron acceptor. This article demonstrates a previously unidentified anaerobic extracellular electron transfer metabolism that operates in aerobic β –proteobacterial ammonia oxidizers and reconstructs the evolutionary history of this metabolism, linking it to the early history of Earth’s oxygenation. Our approach contributes to the understanding of metabolisms in the N-cycle and their evolution on Earth, as well as how aerobic microbes manage to retain energy generation under oxygen-limiting or depleted conditions. AUTHOR CONTRIBUTIONS AG designed the physiological research with PRG and the phylogenetic research with GF; AG performed the research, AG analyzed the data with PRG and GF. AG wrote the paper, and all authors edited and approved the manuscript.

Victor G. Stepanov, Yeyuan Xiao, April J. Lopez et al.

Genome Announcements • 2016

ABSTRACT The perchlorate-reducing strain Marinobacter sp. strain P4B1 was isolated from a long-term perchlorate-degrading enrichment culture seeded with marine sediment. The draft genome of Marinobacter sp. P4B1 is comprised of the bacterial chromosome (3.60 Mbp, G+C 58.51%, 3,269 predicted genes) and its associated plasmid pMARS01 (0.14 Mbp, G+C 52.95%, 165 predicted genes).

Wen‐ting Cui, Sha‐sha Zhang, Meng Li et al.

Biotechnology and Applied Biochemistry • 2025

ABSTRACT The potential applications of microbial fuel cells (MFCs) in wastewater treatment and energy recovery have been investigated. MFCs harness the metabolic activity of microorganisms to generate electricity from organic compounds, which is highly important for preventing environmental pollution and constructing an ecological civilization. To address the safety limitations of pathogenic electrogenic bacteria in MFCs, this study isolated two novel nonpathogenic strains, Cellulosimicrobium 99‐1 and Listeria innocua 5‐2, from livestock samples. Their synergistic interaction boosted voltage output by 8.2% (exceeding 400 mV) compared to pure cultures while achieving 90.6% chemical oxygen demand (COD) and 74% total nitrogen removal in domestic wastewater, demonstrating dual advantages in biosecurity and treatment efficiency. This study provides experimental data and theoretical support for the application of MFC technology in environmental engineering, laying a foundation for further optimizing MFC design and improving wastewater treatment efficiency.

Yohanna Anisa Indriyani, Iman Rusmana, Syaiful Anwar et al.

Biota : Jurnal Ilmiah Ilmu-Ilmu Hayati • 2025

Electrogenic microbes have been exploited in the microbial fuel cell (MFC) system for harvesting bioelectricity. Electrogens are widely distributed in various environments, but the exploration of this microbial group from ecosystems in Indonesia is still limited. This present study aimed to isolate the electrogenic bacteria from sediments of two waterlogged ecosystems (dam and paddy field) using serial dilution into extinction method prior to streak plate method on the solid thioglycollate media supplemented with Fe3+. Electrochemical evaluation was conducted in glucose-fed dual-chamber MFC by using Arduino UNO-based data logger for the accurate monitoring of electricity production in the term of open circuit voltage (OCV). A total of 54 electrogens were successfully isolated from these two ecosystems, ranging from weakness to strongest electrogens (OCV >800 mV) and ranging from microaerophilic, aerotolerant and facultative anaerobes, to obligate anaerobes. This result also suggested that sediment of waterlogged ecosystems rich in electron donor and solid acceptor electron compounds could potentially host electrogenic microbes. The exploration of electrogens from many other waterlogged ecosystems in Indonesia, both natural and anthropic ecosystems, could be conducted to collect genetic resources of novel electrogenic bacteria for the development of MFC technology in Indonesia.

Palash Pan, Abhishek Samanta, Kajari Roy et al.

Biosciences Biotechnology Research Asia • 2025

ABSTRACT: Microbial fuel cells (MFCs) harness microorganisms' metabolic processes to convert organic compounds into electricity, offering an eco-friendly energy solution. As the global demand for sustainable energy sources increases, MFCs have emerged as a promising technology for both bioremediation and biomass power generation. However, optimizing microbial performance remains a challenge, particularly in identifying and enhancing the role of electroactive bacteria. Among them, Lysinibacillus sp. has shown potential for efficient electron transfer, yet its contributions to MFC performance remain underexplored. To address this gap, bibliometric analysis provides a systematic approach to mapping research trends, identifying key contributors, and evaluating the evolution of scientific knowledge in this field. This study employs bibliometric analysis via Dimensions AI and VOSviewer to explore research on Lysinibacillus sp. in MFCs. The analysis identified 3029 publications from 2015 to 2024, peaking in 2022 and 2023. Dominant fields include biological sciences and microbiology, with 1210 and 571 publications, respectively. Varjani, Sunita was the most prolific author, and India was the leading contributor with 610 documents and 19,663 citations. Bioresource Technology was the top journal, and Amity University led in co-authorship. Key references are Geyer, R., and Logan, B.E. The analysis provides insights into research trends, significant publications, and future directions for advancing MFC technologies.

Bijentimala Keisham, Sheldon Cotts, Vikas Berry

ECS Meeting Abstracts • 2020

We report on the enhancement of the phononic excitation in electrogenic bacteria due to the electron transfer to interfaced graphene quantum dots (GQDs). This phenomenon enables GQDs to detect otherwise unobservable bacterial Raman peaks by chemeo-phononic amplification by a factor of ten. We show confirmation of the charge transfer ability of the electrogenic bacteria into GQD and provides a platform for chemical enhancement phenomena for biological sensing at the cellular level. This study also reports on the electrogenic bacteria’s phonon-polarization directly related to the chemical enhancement from the GQDs.

Roman Serikovich Urazbayev, Darya Vladimirovna Ryabokon

Chronos • 2022

Existing electronic devices on the market are composed of inorganic, inanimate materials. However, in the future, the introduction of live microorganisms in various kinds of technology is expected. As a result of research, it is expected to obtain such a material that will promote the cultivation of exoelectrogenic bacteria and the output of electricity obtained from them to the electrode with low losses.

Desislava Teneva, Petko Denev

Microorganisms • 2023

Ensuring the microbiological safety of food products is a pressing global concern. With the increasing resistance of microorganisms to chemical agents and the declining effectiveness of synthetic preservatives, there is a growing need for alternative sources of natural, bioactive compounds with antimicrobial activity. The incorporation of probiotics and plant extracts into food formulations not only enriches foodstuffs with microorganisms and phytochemicals with biologically active compounds, but also provides a means for product preservation. The current review considers the importance of the process of biological preservation for providing safe foods with high biological value, natural origin and composition, and prolonged shelf life, thereby improving consumers’ quality of life. To accomplish this goal, this review presents a series of examples showcasing natural preservatives, including beneficial bacteria, yeasts, and their metabolites, as well as phenolic compounds, terpenoids, and alkaloids from plant extracts. By summarizing numerous studies, identifying research challenges and regulatory barriers for their wider use, and outlining future directions for investigation, this article makes an original contribution to the field of biopreservation.

Nan Wang, Weiwei Wu, Jiawen Pan et al.

Microorganisms • 2019

Zearalenone (ZEA) is a mycotoxin produced by Fusarium fungi that is commonly found in cereal crops. ZEA has an estrogen-like effect which affects the reproductive function of animals. It also damages the liver and kidneys and reduces immune function which leads to cytotoxicity and immunotoxicity. At present, the detoxification of mycotoxins is mainly accomplished using biological methods. Microbial-based methods involve zearalenone conversion or adsorption, but not all transformation products are nontoxic. In this paper, the non-pathogenic microorganisms which have been found to detoxify ZEA in recent years are summarized. Then, two mechanisms by which ZEA can be detoxified (adsorption and biotransformation) are discussed in more detail. The compounds produced by the subsequent degradation of ZEA and the heterogeneous expression of ZEA-degrading enzymes are also analyzed. The development trends in the use of probiotics as a ZEA detoxification strategy are also evaluated. The overall purpose of this paper is to provide a reliable reference strategy for the biological detoxification of ZEA.

Aparna P. Murali, Monika Trząskowska, Joanna Trafialek

Microorganisms • 2023

The review aimed to analyse the latest data on microorganisms present in organic food, both beneficial and unwanted. In conclusion, organic food’s microbial quality is generally similar to that of conventionally produced food. However, some studies suggest that organic food may contain fewer pathogens, such as antibiotic-resistant strains, due to the absence of antibiotic use in organic farming practices. However, there is little discussion and data regarding the importance of some methods used in organic farming and the risk of food pathogens presence. Concerning data gaps, it is necessary to plan and perform detailed studies of the microbiological safety of organic food, including foodborne viruses and parasites and factors related to this method of cultivation and specific processing requirements. Such knowledge is essential for more effective management of the safety of this food. The use of beneficial bacteria in organic food production has not yet been widely addressed in the scientific literature. This is particularly desirable due to the properties of the separately researched probiotics and the organic food matrix. The microbiological quality of organic food and its potential impact on human health is worth further research to confirm its safety and to assess the beneficial properties resulting from the addition of probiotics.

Dan Sun, Shaoan Cheng, Aijie Wang et al.

Genome Announcements • 2016

ABSTRACT Strain SD-1 is the type strain of the species Geobacter anodireducens , which was originally isolated from a microbial fuel cell reactor in the United States. The characteristic of this bacterium is its high electrochemical activity. Here, we report the fully assembled genome and plasmid sequence of G. anodireducens SD-1 T .

Isidoro Garcia Garcia, Maria Gullo

Acetic Acid Bacteria • 2013

Acetic acid bacteria are a group of microorganisms able to achieve oxidation reactions from sugars and alcohols mainly producing organic acids, aldehydes and ketones. When the substrate is ethanol, acetic acid is produced, thus giving the common name <em>acetic acid bacteria</em> to this bacterial group. Acetic acid bacteria are of considerable importance in food and beverages as beneficial or detrimental bacteria. Nowadays, they play a role as biocatalysts contributing to more eco-friendly bio-based processes, since the production of important industrial molecules generate high environmental impact when chemically synthesized. Although they have a high biotechnological potential, their use at industrial scale is still restricted...

Luciana De Vero, Paolo Giudici

Acetic Acid Bacteria • 2013

Acetic acid bacteria (AAB) are obligate aerobic microorganisms which have large significance in human life. Traditionally, AAB species have been used to produce fermented food and beverages thanks to their ability to oxidize ethanol to acetic acid. Moreover, in the last decades, they have been extensively investigated for other industrial biotechnology applications as the development of processes for highvalue products or biosensors. The potential exploitation of AAB diversity requires the existence of microbial culture collections, which are able to supply not only strains but essential data for fundamental microbial research. Therefore, microbial collections can be helpful to provide critical insights into AAB physiology and metabolism as well as integrate sequence data with transcriptional and functional studies to better define complex traits and develop new potential microbial processes. This article reviews the significance of microbial collections, with an overview of the well-known European Biological Resources Centers (BRCs) collecting AAB, and provides an insight into their cultivability and metabolic activity. It also discusses appropriate techniques in preserving <em>authentic</em> strains, quality control implications, databases and BRC networking as well as connections among collections and stakeholders.

Nia Z. Petrova, Soujanya Kuntam, Milán Szabó et al.

bioRxiv (Cold Spring Harbor Laboratory) • 2025

Abstract Exoelectrogenesis is the ability of living cells to export electrons. In photosynthetic organisms, exoelectrogenesis is of particular interest because it can be used for transduction of solar energy into electric current in biophotovoltaics or reducing power for biocatalysis. Previously, we identified and characterized the green microalga Parachlorella kessleri MACC-38 producing unprecedented current largely dependent on the photosynthetic electron transport chain (PETC). In this study, our comparative photosynthetic characterization demonstrates that chlororespiration is a crucial factor maintaining the PETC redox balance in MACC-38. Our data points that the oxidative pentose phosphate pathway (OPPP) is activated during exoelectrogenesis to meet the increased demand of reducing power. We hypothesize that chlororespitration prevents oversaturation of PETC during OPPP activation. These findings provide valuable insights into the fundamental mechanisms of exoelectrogenesis in green algae. By elucidating the complex interconnection between PETC, OPPP and exoelectrogenesis, our results pave the way towards improved bioelectrochemical and biocatalysis technologies.

Yong Hu, David Rehnlund, Edina Klein et al.

bioRxiv (Cold Spring Harbor Laboratory) • 2019

Abstract The 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.

Xiaoli Zhang, Yuxia Liu, Qixing Zhou et al.

Environmental Science & Technology • 2023

Electroactive microbes can conduct extracellular electron transfer and have the potential to be applied as a bioresource to regulate soil geochemical properties and microbial communities. In this study, we incubated Fe-limited and Fe-enriched farmland soil together with electroactive microbes for 30 days; both soils were incubated with electroactive microbes and a common iron mineral, ferrihydrite. Our results indicated that the exogenous electroactive microbes decreased soil pH, total organic carbon (TOC), and total nitrogen (TN) but increased soil conductivity and promoted Fe(III) reduction. The addition of electroactive microbes also changed the soil microbial community from Firmicutes-dominated to Proteobacteria-dominated. Moreover, the total number of detected microbial species in the soil decreased from over 700 to less than 500. Importantly, the coexistence of N-transforming bacteria, Fe(III)-reducing bacteria and methanogens was also observed with the addition of electroactive microbes in Fe-rich soil, indicating the accelerated interspecies electron transfer of functional microflora.