Discover insights from thousands of peer-reviewed papers on microbial electrochemical systems
T. Jayaraman, Sunitha Salla, Senthil R A et al.
Nanotechnology · 2019
Zinc oxide (ZnO) is an adaptable material that has distinctive properties, such as high-sensitivity, large specific area, non-toxicity, good compatibility and a high isoelectric point, which favours it to be considered with a few exceptions. It is the most desirable group of nanostructure as far as both structure and properties. The unique and tuneable properties of nanostructured ZnO shows excellent stability in chemically as well as thermally stable n-type semiconducting material with wide applications such as in luminescent material, supercapacitors, battery, solar cells, photocatalysis, biosensors, biomedical and biological applications in the form of bulk crystal, thin film and pellets. The nanosized materials exhibit higher dissolution rates as well as higher solubility when compared to the bulk materials. This review significantly focused on the current improvement in ZnO-based nanomaterials/composites/doped materials for the application in the field of energy storage and conversion devices and biological applications. Special deliberation has been paid on supercapacitors, Li-ion batteries, dye-sensitized solar cells, photocatalysis, biosensors, biomedical and biological applications. Finally, the benefits of ZnO-based materials for the utilizations in the field of energy and biological sciences are moreover consistently analysed.
S. Burley, H. Berman, Charmi Bhikadiya et al.
Nucleic Acids Research · 2018
Abstract The Research Collaboratory for Structural Bioinformatics Protein Data Bank (RCSB PDB, rcsb.org), the US data center for the global PDB archive, serves thousands of Data Depositors in the Americas and Oceania and makes 3D macromolecular structure data available at no charge and without usage restrictions to more than 1 million rcsb.org Users worldwide and 600 000 pdb101.rcsb.org education-focused Users around the globe. PDB Data Depositors include structural biologists using macromolecular crystallography, nuclear magnetic resonance spectroscopy and 3D electron microscopy. PDB Data Consumers include researchers, educators and students studying Fundamental Biology, Biomedicine, Biotechnology and Energy. Recent reorganization of RCSB PDB activities into four integrated, interdependent services is described in detail, together with tools and resources added over the past 2 years to RCSB PDB web portals in support of a ‘Structural View of Biology.’
E. C. Hann, Sean Overa, Marcus Harland-Dunaway et al.
Nature Food · 2022
Artificial photosynthesis systems are proposed as an efficient alternative route to capture CO2 to produce additional food for growing global demand. Here a two-step CO2 electrolyser system was developed to produce a highly concentrated acetate stream with a 57% carbon selectivity (CO2 to acetate), allowing its direct use for the heterotrophic cultivation of yeast, mushroom-producing fungus and a photosynthetic green alga, in the dark without inputs from biological photosynthesis. An evaluation of nine crop plants found that carbon from exogenously supplied acetate incorporates into biomass through major metabolic pathways. Coupling this approach to existing photovoltaic systems could increase solar-to-food energy conversion efficiency by about fourfold over biological photosynthesis, reducing the solar footprint required. This technology allows for a reimagination of how food can be produced in controlled environments. Coupling a two-step electrochemical system that converts CO2 to acetate with photovoltaics increases solar-to-food energy conversion efficiency, providing an alternative route to produce food from carbon dioxide and electricity, independent of biological photosynthesis.
A. Batiza, M. Gruhl, Bo Zhang et al.
CBE—Life Sciences Education · 2013
The Students Understanding eNergy (SUN) Project reports significant long-term effects on biology teacher knowledge and self-efficacy regarding biological energy transfer. Teachers use a hydrogen fuel cell and manipulatives to develop a model of energy transfer based on electrons moving in thermodynamically spontaneous reactions.
Minah Lee, Jihyun Hong, D. Seo et al.
Angewandte Chemie International Edition · 2013
Energy transduction and storage in biological systems involve multiply coupled, stepwise reduction/oxidation of energycarrying molecules such as adenosine triphosphate (ATP), nicotinamide, and flavin cofactors. These are synthesized as a result of oxidation during citric acid cycles in mitochondria or during photosynthesis in chloroplasts, and high energies stored in their chemical bonds are consequently harnessed for many biological reactions. Phosphorylation and protonation are key underlying mechanisms that allow for reversible cycling and regulate the molecule-specific redox potential. A sequential progression of electron transfer through the redox cascades as well as continuous recycling of the redox centers enables efficient energy use in biological systems. The biological energy transductionmechanism hints at the construction of a man-made energy storage system. Since the pioneering work by Tarascon and co-workers towards a sustainable lithium rechargeable battery received significant resonance, organic materials such as carbonyl, carboxy, or quinone-based compounds have been demonstrated to be bio-inspired organic electrodes. The imitation of redoxactive plastoquinone and ubiquinone cofactors through the use of redox-active C=O functionalities in organic electrodes is a significant step forward to biomimetic energy storage. However, the biological energy transduction is based on numerous redox centers of versatile functionalities available in nature, not limited to the simple redox active C=O functionalities. Consideration of how natural energy transduction systems function at organelle or cellular levels by elucidating the basic components and their operating principles selected by evolution will enrich the biomimetic strategy for efficient and green energy storage. Flavins are one of most structurally and functionally versatile redox centers in nature, catalyzing an enormous range of biotransformations and electron-transfer reactions, which occur over a wide potential range (> 500 mV). The extraordinary versatility of flavins stems from their ability to engage in either oneor twoelectron-transfer redox processes, accompanying proton transfer at the nitrogen atoms of diazabutadiene motif. In the respiratory electron transport chain, for example, electrons from reduced flavin adenine dinucleotide (FADH2) are transported along a group of proteins located in the inner membrane of mitochondria to induce proton pumping across the membrane, as illustrated in Figure 1a (left). This process generates an electrochemical proton gradient, which results in the formation of high-energy ATP. FAD is reduced again in the citric acid cycle of mitochondria, which enables continuous recycling of flavin redox centers. A close analogy exists between the key components, facilitating respiration and battery operation (Figure 1a); charged ions (H or Li) and electrons, which are derived from flavin redox centers, are unidirectionally transported in a stoichiometric manner using separated paths. This creates chemical gradients across membranes, and finally results in the formation of highenergy species such as ATP and metallic lithium. Herein, we report on the possibility of using the energystorage mechanism of flavin redox cycling in mitochondria to lithium rechargeable batteries. According to our results, flavin electrodes were capable of reversibly storing and releasing two lithium ions and two electrons per formula unit. Redox reactions in flavin electrodes were thoroughly investigated using the combined analyses of ex situ characterizations and density functional theory (DFT)-based calculations. We found that the flavin redox reaction occurs during battery operation at the nitrogen atoms of the diazabutadiene motif in flavin molecules using two successive single-electron transfer steps, in a similar way to the proton-coupled electron transfer in flavoenzymes. Molecular tuning by chemical substitution on the isoalloxazine ring significantly improved electrochemical performances in terms of an average redox potential, a gravimetric capacity, and stability, resulting in a high-energy density comparable to that of LiFePO4, the [*] M. Lee, D. H. Nam, Prof. C. B. Park Department of Materials Science and Engineering Korea Advanced Institute of Science and Technology Daejeon 305-701 (Korea) E-mail: parkcb@kaist.ac.kr J. Hong, Dr. D.-H. Seo, Prof. K. T. Nam, Prof. K. Kang Center for Nanoparticle Research Institute for Basic Science (IBS) Department of Materials Science and Engineering Research Institute of Advanced Materials Seoul National University, Seoul 151-742 (Korea) E-mail: matlgen1@snu.ac.kr [] These authors contributed equally to this work.
S. Sid, A. Volant, G. Lesage et al.
Water Science and Technology · 2017
Energy consumption and sludge production minimization represent rising challenges for wastewater treatment plants (WWTPs). The goal of this study is to investigate how energy is consumed throughout the whole plant and how operating conditions affect this energy demand. A WWTP based on the activated sludge process was selected as a case study. Simulations were performed using a pre-compiled model implemented in GPS-X simulation software. Model validation was carried out by comparing experimental and modeling data of the dynamic behavior of the mixed liquor suspended solids (MLSS) concentration and nitrogen compounds concentration, energy consumption for aeration, mixing and sludge treatment and annual sludge production over a three year exercise. In this plant, the energy required for bioreactor aeration was calculated at approximately 44% of the total energy demand. A cost optimization strategy was applied by varying the MLSS concentrations (from 1 to 8 gTSS/L) while recording energy consumption, sludge production and effluent quality. An increase of MLSS led to an increase of the oxygen requirement for biomass aeration, but it also reduced total sludge production. Results permit identification of a key MLSS concentration allowing identification of the best compromise between levels of treatment required, biological energy demand and sludge production while minimizing the overall costs.
V. Müller, V. Hess
Frontiers in Microbiology · 2017
Some anaerobic archaea and bacteria live on substrates that do not allow the synthesis of one mol of ATP per mol of substrate via substrate level phosphorylation (SLP). Energy conservation in these cases is only possible by a chemiosmotic mechanism that involves the generation of an electrochemical ion gradient across the cytoplasmic membrane that then drives ATP synthesis via an ATP synthase. The minimal amount of energy required for ATP synthesis is thus dependent on the magnitude of the electrochemical ion gradient, the phosphorylation potential in the cell and the ion/ATP ratio of the ATP synthase. It was always thought that the minimum biological energy quantum is defined as the amount of energy required to translocate one ion across the cytoplasmic membrane. We will discuss the thermodynamics of the reactions involved in chemiosmosis and describe the limitations for ion transport and ATP synthesis that led to the proposal that at least −20 kJ/mol are required for ATP synthesis. We will challenge this hypothesis by arguing that the enzyme energizing the membrane may translocate net less than one ion: By using a primary pump connected to an antiporter module a stoichiometry below one can be obtained, implying that the minimum biological energy quantum that sustains life is even lower than assumed to date.
W. Buckel, R. Thauer
Chemical Reviews · 2018
There are two types of electron bifurcation (EB), either quinone- or flavin-based (QBEB/FBEB), that involve reduction of a quinone or flavin by a two-electron transfer and two reoxidations by a high- and low-potential one-electron acceptor with a reactive semiquinone intermediate. In QBEB, the reduced low-potential acceptor (cytochrome b) is exclusively used to generate ΔμH+. In FBEB, the "energy-rich" low-potential reduced ferredoxin or flavodoxin has dual function. It can give rise to ΔμH+/Na+ via a ferredoxin:NAD reductase (Rnf) or ferredoxin:proton reductase (Ech) or conducts difficult reductions such as CO2 to CO. The QBEB membrane complexes are similar in structure and function and occur in all domains of life. In contrast, FBEB complexes are soluble and occur only in strictly anaerobic bacteria and archaea (FixABCX being an exception). The FBEB complexes constitute a group consisting of four unrelated families that contain (1) electron-transferring flavoproteins (EtfAB), (2) NAD(P)H dehydrogenase (NuoF homologues), (3) heterodisulfide reductase (HdrABC) or HdrABC homologues, and (4) NADH-dependent ferredoxin:NADP reductase (NfnAB). The crystal structures and electron transport of EtfAB-butyryl-CoA dehydrogenase and NfnAB are compared with those of complex III of the respiratory chain (cytochrome bc1), whereby unexpected common features have become apparent.
Ville R. I. Kaila
Journal of The Royal Society Interface · 2018
Biological energy conversion is driven by efficient enzymes that capture, store and transfer protons and electrons across large distances. Recent advances in structural biology have provided atomic-scale blueprints of these types of remarkable molecular machinery, which together with biochemical, biophysical and computational experiments allow us to derive detailed energy transduction mechanisms for the first time. Here, I present one of the most intricate and least understood types of biological energy conversion machinery, the respiratory complex I, and how its redox-driven proton-pump catalyses charge transfer across approximately 300 Å distances. After discussing the functional elements of complex I, a putative mechanistic model for its action-at-a-distance effect is presented, and functional parallels are drawn to other redox- and light-driven ion pumps.
Julia M. Kelliher, Aaron J. Robinson, Reid Longley et al.
Microbiome · 2023
Abstract As microbiome research has progressed, it has become clear that most, if not all, eukaryotic organisms are hosts to microbiomes composed of prokaryotes, other eukaryotes, and viruses. Fungi have only recently been considered holobionts with their own microbiomes, as filamentous fungi have been found to harbor bacteria (including cyanobacteria), mycoviruses, other fungi, and whole algal cells within their hyphae. Constituents of this complex endohyphal microbiome have been interrogated using multi-omic approaches. However, a lack of tools, techniques, and standardization for integrative multi-omics for small-scale microbiomes (e.g., intracellular microbiomes) has limited progress towards investigating and understanding the total diversity of the endohyphal microbiome and its functional impacts on fungal hosts. Understanding microbiome impacts on fungal hosts will advance explorations of how “microbiomes within microbiomes” affect broader microbial community dynamics and ecological functions. Progress to date as well as ongoing challenges of performing integrative multi-omics on the endohyphal microbiome is discussed herein. Addressing the challenges associated with the sample extraction, sample preparation, multi-omic data generation, and multi-omic data analysis and integration will help advance current knowledge of the endohyphal microbiome and provide a road map for shrinking microbiome investigations to smaller scales.
Abraham Szőke, Janos Hajdu
Structural Dynamics · 2016
We have argued previously [Szoke et al., FEBS Lett. 553, 18–20 (2003); Curr. Chem. Biol. 1, 53–57 (2007)] that energy utilization and evolution are emergent properties based on a small number of established laws of physics and chemistry. The relevant laws constitute a framework for biology on a level intermediate between quantum chemistry and cell biology. There are legitimate questions whether these concepts are valid at the mesoscopic level. Such systems fluctuate appreciably, so it is not clear what their efficiency is. Advances in fluctuation theorems allow the description of such systems on a molecular level. We attempt to clarify this topic and bridge the biochemical and physical descriptions of mesoscopic systems.
Peter P. Edwards, Vladimir L. Kuznetsov
Energy... beyond oil · 2007
Hydrogen is the simplest and most abundant chemical element in our universe— it is the power source that fuels the Sun and its oxide forms the oceans that cover three quarters of our planet. This ubiquitous element could be part of our urgent quest for a cleaner, greener future. Hydrogen, in association with fuel cells, is widely considered to be pivotal to our world’s energy requirements for the twenty-first century and it could potentially redefine the future global energy economy by replacing a carbon-based fossil fuel energy economy. The principal drivers behind the sustainable hydrogen energy vision are therefore: • the urgent need for a reduction in global carbon dioxide emissions; • the improvement of urban (local) air quality; • the abiding concerns about the long-term viability of fossil fuel resources and the security of our energy supply; • the creation of a new industrial and technological energy base—a base for innovation in the science and technology of a hydrogen/fuel cell energy landscape. The ultimate realization of a hydrogen-based economy could confer enormous environmental and economic benefits, together with enhanced security of energy supply. However, the transition from a carbon-based(fossil fuel) energy system to a hydrogen-based economy involves significant scientific, technological, and socio-economic barriers. These include: • low-carbon hydrogen production from clean or renewable sources; • low-cost hydrogen storage; • low-cost fuel cells; • large-scale supporting infrastructure, and • perceived safety problems. In the present chapter we outline the basis of the growing worldwide interest in hydrogen energy and examine some of the important issues relating to the future development of hydrogen as an energy vector. As a ‘snapshot’ of international activity, we note, for example, that Japan regards the development and dissemination of fuel cells and hydrogen technologies as essential: the Ministry of Economy and Industry (METI) has set numerical targets of 5 million fuel cell vehicles and10 million kW for the total power generation by stationary fuel cells by 2020. To meet these targets, METI has allocated an annual budget of some £150 million over four years.
Murali Krishna Pasupuleti
Sustainable Materials for Clean Energy · 2025
This chapter explores the pivotal role of sustainable materials in advancing clean energy technologies, with a focus on nanomaterials, next-generation solar cells, and hydrogen innovations. It highlights how nanostructured materials are transforming energy systems by improving the efficiency, stability, and scalability of batteries, supercapacitors, solar panels, and hydrogen production processes. The chapter discusses perovskite solar cells, quantum dot photovoltaics, and organic photovoltaic cells as breakthroughs in renewable energy generation, emphasizing their potential for low-cost, flexible, and sustainable applications. In the realm of hydrogen innovation, the chapter covers advancements in green hydrogen production, nanomaterial-enhanced electrolysis, hydrogen storage solutions, and fuel cells that offer zero-emission alternatives for industries and transportation. It also examines emerging trends such as bio-inspired materials, self-healing nanomaterials, and next-generation catalysts, while addressing challenges in scalability and cost-effectiveness. Finally, the chapter underscores the importance of policy frameworks, industry-academia collaborations, and circular economy practices to ensure the widespread adoption of sustainable materials for a decarbonized and resilient energy future. Keywords: sustainable materials, clean energy, nanomaterials, solar cells, hydrogen innovation, perovskite solar cells, quantum dot photovoltaics, green hydrogen, nanocatalysts, hydrogen fuel cells, renewable energy, energy storage, photocatalysis, scalable energy solutions, carbon-neutral technologies, self-healing materials, bio-inspired materials, circular economy, energy transition.
Ashwani K. Gupta
Handbook of Clean Energy Systems · 2015
Abstract Waste and biomass include different kinds of organic and inorganic materials including wood, trees, agricultural, municipal, medical, hazardous, electronic, industrial solid wastes, and waste glass, metals, and plastics. Waste is a growing problem to the society worldwide. Increased waste production is directly related to increased gross domestic product ( GDP ) so that one must seek options for their safe and environmentally benign disposal. The old practice of landfills, although still in use in many countries, is less acceptable as this causes odors and nuisance to the nearby community and can be leachable to ground water. Thermal destruction and incineration is now widely used as it provides energy recovery (both thermal and electricity), mass and volume reduction of the waste, and the remaining residue can be used for construction material or discarded at landfills. Pyrolysis and gasification offers clean reforming of wastes to syngas, which can also be converted into liquid fuels. Much of the work on gasification of wastes is at the laboratory scale so that the favorable results obtained can be used at pilot‐ and demonstration‐scale plants, akin to coal gasification plants. Waste and biomass can also be converted into useful clean refuse‐derived fuel and value added products of activated carbon and torrefied material. It is expected that the fundamental information on pyrolysis and gasification provided here will assist in the design and operation of advanced gasifiers with eliminated tars and char. The reforming of wastes to useful materials and value added products provide clean energy to support energy sustainability.
Umberto Desideri, Jinyue Yan
Handbook of Clean Energy Systems · 2015
Abstract The power plants that have provided energy in the last century are facing a difficult future as renewable energy sources are taking a higher and higher share of the power generation. This is more evident in some areas of Europe, but the trend is towards a significant increase of renewable energy in the near future. Conventional power plants, such as vapor cycles, gas turbines and internal combustion engines, which have powered our lives in the last 150 years, are now required new performance and environmental goals: high efficiency, flexibility and low or zero emissions. The research and development in the last 60 years have provided several solutions to improve the performance of those power plants. There are clear directions to follow to achieve low or zero emissions, but knowledge is not enough to reach the goals. Therefore, there is still a great need to find new and innovative solutions that will be a breakthrough towards the clean energy systems of the future. This volume presents a number of energy conversion processes and systems which are currently being used in very large numbers, their development to the current state of art, the efforts that are still necessary to make this systems really “clean”, in order to stimulate the readers, either researchers or students, in using their brain to improve them in order to have “clean”, available and reliable systems for power generation.
Babatunde Olateju, Amit Kumar
Handbook of Clean Energy Systems · 2015
Abstract In the context of a global energy market with rising demand along with an increasing aversion to greenhouse gas ( GHG ) emissions, the demand for clean energy production and, in particular, environmentally benign energy carriers and storage media are considerable. In this article, the production of hydrogen as a clean energy storage medium is addressed from a techno‐economic perspective. Furthermore, emphasis is placed upon hydrogen production channels that can facilitate large‐scale production and significant GHG mitigation at a relatively moderate cost. A number of hydrogen pathways are considered, which include wind‐powered electrolytic hydrogen production, biohydrogen production via gasification and pyrolysis, steam methane reforming ( SMR ) with and without carbon capture and sequestration ( CCS ), and underground coal gasification ( UCG ) with and without CCS . This article presents a holistic discussion of the salient techno‐economic trade‐offs and implications, challenges, and competitive advantages, as well as the environmental footprint pertaining to each hydrogen pathway.
B. Senthil Rathi, V. Dinesh Aravind, G. Ranjith et al.
MRS Energy & Sustainability · 2024
Abstract Microalgae present an enticing alternative to conventional fossil fuel-dependent technologies for producing hydrogen, offering an intriguing and sustainable energy source. Numerous strains of microalgae are under investigation for their capacity to generate hydrogen, alongside various techniques and breakthroughs being developed to optimize the process. However, significant hurdles must be addressed for commercial viability, including the high manufacturing costs and the necessity for efficient harvesting and sorting methods. This paper delves into several aspects concerning hydrogen synthesis in algae, encompassing microalgae anatomy and physiology, hydrogen synthesis via photosynthesis and dark fermentation, and the integration of microalgal hydrogen synthesis with other renewable energy sources. The potential for microalgal hydrogen generation is considered pivotal in transitioning toward a future reliant on more renewable and sustainable energy sources. This review aims to serve as a valuable resource for researchers, decision-makers, and anyone interested in the advancement of environmentally conscious energy technology. The primary objective of this research paper is to scrutinize the challenges, opportunities, and potential outcomes associated with eco-friendly bio-hydrogen production through algae. It evaluates the current technological hurdles facing bio-hydrogen synthesis from algae. Graphical abstract Highlights Interest in developing renewable fuels, such as hydrogen from biomass, has surged due to escalating energy demands and the imperative to curtail greenhouse gas emissions. Overview of bio-hydrogen production pathway, reactor designs, and configurations for bio-hydrogen production from bio-algae were explored. Environmental, social sustainability and economic feasibility have been reviewed. Discussion Will bio-hydrogen from bio-algae be a future renewable energy? Which is the best pathway to produce bio-hydrogen from bio-algae? Regarding greenhouse gas emissions, how does the generation of bio-hydrogen from bio-algae compare to conventional hydrogen production techniques? What difficulties lie in increasing the amount of bio-hydrogen produced by bio-algae to satisfy major energy demands?
M.V.R. Prasad
· 2022
"The current socio-economic situation of India presents complex problems of environmental pollution and decline of farm income coupled with rural poverty. There are no simple solutions to the above issues; but a careful analysis of the available options does suggest some silver-linings amidst the rapidly darkening horizons. One such ameliorating options would be gradual restoration of soil fertility and enhancement of agri-ecosystems by including productive tree plantations in rural scenario. Pongamia pinnata, popularly known in India as Karanj has been found to be one of the most sustainable trees with regard to its soil enhancement and carbon sequestration properties apart from its stability in seed and oil yield. Pongamia pinnata is also credited with several preventive and curative properties as established by Ayurvedic medicine. It may be recalled that in the decades of nineteen seventies a few villages reaped sustainable incomes in the face of acute and chronic droughts that plagued the nation, solely due to the availability of some old Pongamia / karanj tree stands around those zones. Kranj oil has exhibited promise as a source of green energy. Nevertheless, the research on improvement of Karanj and its management as a productive plantation is nebulous. It is heartening that the Monograph on Karanj by Dr. M.V.R. Prasad fills this void. Dr. Prasad has been pursuing the work on oil bearing perennial trees of which Pongamaia pinnata has been studied in greater detail during the decades starting from nineteen eighties to date. The Monograph describes clearly as to how Pongamia pinnata could be harnessed to exploit the proven and potential benefits cited above, in addition to giving valuable information on its genetic improvement and plantation management. This Monograph on Pongomia will serve as a valuable reference book for the Agricultural Scientists, Extension workers, students as well as farmers."
Gursimran Kaur, Babli Dhiman
BIO Web of Conferences · 2024
This article's primary objective is to evaluate, within the Indian setting, the degree to which energy commodities and energy stock prices correlate and are causally related. Weekly spot price data has been sourced from the Multi Commodity Exchange and the National Stock Exchange, which spans from January 2007 to December 2021. This study employs Auto-regressive Distributive (ARDL) Bound test along with Johansen co-integration approach to understand the co-integration between the series under study. The findings support the idea that the energy stock index listed on the National Stock Exchange (NSE) and the energy commodities traded on the Multi Commodity Exchange (MCX) do not exhibit any co-integration. Furthermore, to investigate the cause-and-effect connection between the energy stock index and energy commodities, Granger Causality test has been utilised, which was introduced by Toda and Yamamoto. The results demonstrate that there is no causal relationship between MCX energy commodities and the NSE energy stock index. Thus, the nonexistence of cointegration and causality between NSE energy index and energy commodities provides portfolio diversification opportunities for the investors to hedge their risk by investing in both energy commodities and energy stock index. Policymakers need to promote deeper integration among these markets by making more regulatory and accounting changes.
M. Mohammadifar, Seokheun Choi
2018 IEEE 12th International Conference on Nano/Molecular Medicine and Engineering (NANOMED) · 2018
We report a novel paper-based sensing strategy based on microbial electrochemical activities, in which a reusable voltage meter integrated with a read-out LED display monitors a self-powered transducing signal from a disposable paper-based sensing strip for lactate monitoring in sweat. This sensor strip self-produced an electrochemical potential difference when electricity-producing bacterial cells (or exoelectrogens) oxidized the biodegradable organic substrate, lactate, and transferred electrons to an electrode. Because the harvested electrons were based on their electrochemical energy conversion and were proportional to the lactate concentration, the voltage output through an external resistor could be used as a transducing signal for lactate monitoring in sweat. The output signal was easily readable with an inexpensive digital multimeter, which could be repeatedly connected to the disposable sensing strip. The LED display showed a linear range of output voltage at 0.0 ~ 40.0 mM lactate concentration (R2 =0.977) with a 100kΩ resistor. Thus, our new sensing system holds great promise in designing portable and low-cost sensors for point-of-care and daily applications.
P. Jegathambal, R. Nisha, K. Parameswari et al.
Applied Water Science · 2019
Electrobiochemical reactor is one of the energy sustainable technologies for desalination which simultaneously treats waste water by microorganisms that are used as the catalyst for removal of salts and energy production. The microbial-induced electrochemical reaction occurring during the process and the energy produced in the reactor induce desalination. The reactor used in this study consists of 3 chambers: anode, middle and cathode which are separated using the ion exchange membranes. In this study, an air cathode with two different catholytes was used and comparative studies were carried out. The use of acidic water in the cathode chamber showed more efficiency than the phosphate-buffered solution. There were maximum removal of 60% electrical conductivity and 100% hardness during treatment. The maximum current of 1 mA and voltage of 850 mV were generated using this reactor. Apart from this, there is a reduction in 45% BOD removal in the anode chamber. The maximum power density and current density obtained were 251.8 mW/m2 and 296.29 mA/m2, respectively. The characterization of the deposited sludge on the membranes during the reaction was performed using scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy.
Beni Camacho-Pérez, Elvira Ríos-Leal, Omar Solorza-Feria et al.
Journal of New Materials for Electrochemical Systems · 2013
Lindane is a chlorinated pesticide known for its toxicity and persistence in the environment. Recently, it has been proposed that soil microbial fuel cell technology (SMFC) could be applied to enhance the removal of organic matter, phenol, and petroleum hydrocarbon in contaminated soil with simultaneous electricity output. Yet, there is no information on the application to remediation of soils polluted with pesticides. The purpose of this research was to evaluate the biodegradation of lindane with simultaneous electricity generation in an electrobiochemical slurry reactor (EBCR). The EBCR was inoculated with a sulfate reducing inoculum acclimated to lindane, it was further characterized, and batch operated for 30 day at room temperature. No external carbon source was supplemented in the experiment 1; the substrate was the soluble natural organic matter (NOM) of the soil. In the experiment 2 the EBCR was supplemented with a stock solution of sucrose: sodium acetate: lactate to give a final concentration of 2g COD/L in the reactor. Results from electrochemical impedance spectroscopy characterization in the EBCR (Experiment 1) showed that the equivalent circuit had a high anodic resistance R1=2064 Ω, cathodic resistance R3 = 192 Ω; and electrolyte/membrane resistance R2 = 7?, totaling a relatively high overall internal resistance Rint of 2263 Ω. During the batch operation, the EBCR showed a 30% lindane removal efficiency along with a maximum volumetric power of 165 mW m-3.This value compared favorably with results corresponding to sediments microbial fuel cells that are used to power weather monitoring systems. The organic matter removal was very high (72% as soluble COD, NOM) whereas the coulombic efficiency was low (5.4%). The latter, although, was higher than values reported for microbial fuel cells that degraded leachate-like effluents. In Experiment 2 of the EBCR both cell characteristics and performance significantly improved. The internal resistance as determined by polarization curve was 102 Ω when the two-electrode sets were connected in parallel. During the batch operation, the EBCR showed a 78% lindane removal and a maximum power volumetric of 634 mW m-3, the organic matter removal was 76% and coulombic efficiency was 15%. Finally, it can be concluded that our EBCR showed a high lindane removal capability and mixing of the slurry phase was associated to improvement of bioremediation and electricity performances of the device.
Tang Nan, Muhammad Zafarullah Baber, Nauman Ahmed et al.
International Journal of Geometric Methods in Modern Physics · 2024
This study deals with the time fractional 1D stochastic Poisson–Nernst–Planck (TFSPNP) system under the effect of multiplicative time noise. The M-truncated derivative (MTD) takes into consideration the fractional order time derivative. This is a steady-state Poisson–Nernst–Planck (PNP) equations that have applications in bioelectric dressings and bandages. To obtain the soliton solutions of TFSPNP, we use the generalized exponential rational functional method. These findings are presented in the form of trigonometric, exponential, and hyperbolic functions. Moreover, to show the effect of multiplicative time noise and MTD, we construct the plot of some solutions in the form of three-dimensional, two-dimensional, and their corresponding contours. These plots clearly show the effect of randomness in the wave structures for the exact solitary wave solutions that are attained. In general, the solutions become more stable when a noise term disrupts their symmetry.
Lihao Guan, Fei Wu, Guoyuan Ren et al.
Chemical Science · 2021
Dehydrogenases (DHs) are widely explored bioelectrocatalysts in the development of enzymatic bioelectronics like biosensors and biofuel cells. However, the relatively low intrinsic reaction rates of DHs which mostly depend on diffusional coenzymes (e.g., NAD+) have limited their bioelectrocatalytic performance in applications such as biosensors with a high sensitivity. In this study, we find that rare-earth elements (REEs) can enhance the activity of NAD+-dependent glutamate dehydrogenase (GDH) toward highly sensitive electrochemical biosensing of glutamate in vivo. Electrochemical studies show that the sensitivity of the GDH-based glutamate biosensor is remarkably enhanced in the presence of REE cations (i.e., Yb3+, La3+ or Eu3+) in solution, of which Yb3+ yields the highest sensitivity increase (ca. 95%). With the potential effect of REE cations on NAD+ electrochemistry being ruled out, homogeneous kinetic assays by steady-state and stopped-flow spectroscopy reveal a two-fold enhancement in the intrinsic reaction rate of GDH by introducing Yb3+, mainly through accelerating the rate-determining NADH releasing step during the catalytic cycle. In-depth structural investigations using small angle X-ray scattering and infrared spectroscopy indicate that Yb3+ induces the backbone compaction of GDH and subtle β-sheet transitions in the active site, which may reduce the energetic barrier to NADH dissociation from the binding pocket as further suggested by molecular dynamics simulation. This study not only unmasks the mechanism of REE-promoted GDH kinetics but also paves a new way to highly sensitive biosensing of glutamate in vivo.
Rong Cai, S. Minteer
ACS Energy Letters · 2018
Nitrogenase is the only enzyme known to reduce molecular nitrogen to ammonia, so it has been an oxidoreductase enzyme of great interest to the electrofuels and catalysis communities, as people consider the design of bioinspired nitrogen reduction catalysts for the production of ammonia. This Perspective details the use of nitrogenase as an electrocatalyst to learn mechanistic information about the electron-transfer mechanism as an inspiration for molecular and metal-based electrocatalysts and for a variety of energy applications, including energy-efficient ammonia production and biofuel cells. This Perspective also addresses the issues and challenges of nitrogenase bioelectrocatalysis that will need to be addressed in the coming years.
Matteo Grattieri, Sarai Patterson, J. Copeland et al.
ChemSusChem · 2020
To date, a major challenge for the implementation of intact bacterial cells in photo-bioelectrochemical systems remains the hindered extracellular electron transfer. Herein, we focus on purple bacteria, photosynthetic microorganisms particularly interesting for bioelectrochemical systems development thanks to their versatile metabolisms. While soluble monomeric redox mediators have been proven as an effective system for electron transfer mediation, their application in the field is not preferable due to toxicity and unwanted release into the environment. We report an abiotic/biotic photo-anode where a bio-inspired redox mediating system is implemented in a 3-D geometry allowing to "electrically wire" intact bacterial cells. The 3-D photo-anode decreased the overpotential required for harvesting photo-excited electrons, operating at +0.073 V vs. SCE. Accordingly, the overpotential is greatly reduced compared to a pioneering Os-redox polymer reported in literature, which required operation at +0.303 V vs. SCE. These results pose the basis for further development of bio-photoanodes for light powered biosensing and power generation.
S. Tsujimura
Bioscience, Biotechnology, and Biochemistry · 2019
ABSTRACT In this review, I present the main highlights of my works in the development of bioelectrocatalysis, which can be used in widespread applications, particularly for the design of biosensor and biofuel cells. In particular, I focus on research progress made in two key bioelectrocatalytic reactions: glucose oxidation by flavin adenine dinucleotide-dependent glucose dehydrogenase and oxygen reduction by bilirubin oxidase. I demonstrate the fundamental principles of bioelectrocatalysis and the requirements for enhancing the catalytic performance, including the choice of a mediator of redox reactions, immobilization, and electrode materials. These methods can allow for achieving control of the bioelectrocatalytic reaction, thereby overcoming obstacles toward their industrial applications. Graphical Abstract From fundamentals to applications of bioelectrocatalysis.
Tomos G. A. A. Harris, N. Heidary, S. Frielingsdorf et al.
ChemElectroChem · 2021
21 22 23 29 33 39 41 42 43 45 46 47 48 49 50 51 52 53 54 55 56 57 In this work, we demonstrate that diazonium electrografting of biocompatible interfaces on transparent conducting oxide indium tin oxide (ITO) can be controlled and optimized to achieve low charge transfer resistance, allowing highly efficient electron transfer to an immobilized model enzyme, the oxygen-tolerant [NiFe]-hydrogenase from Ralstonia eutropha. The use of a radical scavenger enables control of the interface thickness, and thus facilitates maximization of direct electron transfer processes between the enzyme’s active center and the electrode. Using this approach, amine and carboxylic acid functionalities were grafted on ITO, allowing enzyme immobilization both under moderate electrostatic control and covalently via amide bond formation. Despite an initial decrease in catalytic activity, covalent immobilization led to an improve-ment in current stability compared to just electrostatically immobilized enzyme. Given the superior stability of electrografted interfaces in comparison to adsorbed or self-assembled interfaces, we propose electrografting as an alternative approach for the functional immobilization of redox-active enzymes on transparent conducting oxide (TCO) electrodes in bioelectronic devices. distance from sample holder to sputter source of 75 mm. An Argon/oxygen atmosphere of 30:1 was used and the power of the RF was 200 W. A PTFE-coated O-ring was used to seal the electrochemical cell on top of the coated prism, forming a working electrode with a geometric surface area of 0.79 cm 2 in contact with the electrolyte. IR Spectra were recorded between 4000 and 1000 cm (cid:0) 1 with a spectral resolution of 4 cm (cid:0) 1 on a Bruker IFS66v/s spectrometer equipped with a liquid N 2 -cooled, photoconductive Mercury Cadmium Telluride detector. A temperature-controlled, homemade spectroelectrochemical cell was used at a controlled temperature of 25 ° C. 400 scans were averaged per IR spectrum.
P. Buzzetti, P. Blanchard, E. Girotto et al.
Chemical Communications · 2021
A series of polycyclic aromatics, naphthalene, phenanthrene, perylene, pyrene, 1-pyrenebutyric acid N-hydroxysuccinimide ester (pyrene NHS) and coronene, were immobilized via π stacking on carbon nanotube (CNT) electrodes and electro-oxidized in aqueous solutions. The obtained quinones were characterized and evaluated for the mediated electron transfer with FAD dependent glucose dehydrogenase during catalytic glucose oxidation.
Y. Lee, Mengwei Yuan, Rong Cai et al.
ACS Catalysis · 2020
Nitrogenase is the only biological catalyst that is known to be able to convert nitrogen gas to ammonia. In microorganisms, the MoFe catalytic protein of nitrogenase is reduced by a transient Fe pr...
Mizue Wanibuchi, Y. Kitazumi, O. Shirai et al.
Electrochemistry · 2021
The simulation model of the direct electron transfer (DET)-type bioelectrocatalysis at a porous electrode indicates that the catalytic current is proportional to the real surface area ( A ), when A is small. When A is large, the catalytic current is saturated at a limited value controlled by the mass transfer in the porous structure. In this study, the bioelectrocatalytic currents at porous electrodes are analyzed based on their charging currents. Comparisons among the carbon composites constructed with Vulcan and exfoliated graphite (JSP) show that the interface between the Vulcan and JSP particles is more suitable for the DET-type bioelectrocatalysis of bilirubin oxidase (BOD) than that between the particles of the same type. In particular, the most suitable properties were achieved at a Vulcan : JSP ratio of 1 : 1 in the composite electrode. In these composites, the multipoint contact between the BOD molecule and electrode seems to result in a higher DET-type bioelectrocatalytic activity.
Trevor D. Rapson, C. Gregg, R. Allen et al.
ChemSusChem · 2020
There is a growing interest in using ammonia as a liquid carrier of hydrogen for energy applications. Currently, ammonia is produced industrially by the Haber-Bosch process, which requires high temperature and high pressure. In contrast, bacteria have naturally evolved an enzyme known as nitrogenase, that is capable of producing ammonia and hydrogen at ambient temperature and pressure. Therefore, nitrogenases are attractive as a potentially more efficient means to produce ammonia via harnessing the unique properties of this enzyme. In recent years, exciting progress has been made in bioelectrocatalysis using nitrogenases to produce ammonia. Here, we outline the prospects for developing biological ammonia production, highlight the key advances in bioelectrocatalysis by nitrogenases and discuss possible solutions to the obstacles faced in realising this goal.
Xiaobo Liu, Xiaobin Yu
ACS Energy Letters · 2020
Butanol from renewable biomass is a promising advanced biofuel that can be used as an optimal substitute for gasoline in the transportation sectors, and therefore, large-scale industrial production...
M. Komkova, Alexei K Orlov, Andrei A. Galushin et al.
Analytical Chemistry · 2021
Catalytic current of pyrroloquinoline quinone (PQQ)-glucose dehydrogenase (PQQ-GDH) immobilized over electropolymerized methylene green (MG) is increased only five times after the addition of the freely diffusing mediator. This value, being an efficiency criterion for bioelectrocatalysis, is several (three to six) times lower than that for the best reagentless glucose electrodes reported for this enzyme. Thermodynamics of the polyMG|PQQ-GDH electrode is determined by the enzyme-catalyzed reaction pointing to the direct bioelectrocatalysis. PQQ-GDH immobilized over polyMG displays the current plateau region from 0.0 to 0.2 V in the presence of glucose; at 0.00 V, being the optimal potential for biosensing applications, the catalytic current of the polyMG|PQQ-GDH electrode is 700-fold higher than that for the enzyme on a blank electrode. Successful glucose detection in human sweat by means of the corresponding enzyme electrode confirms that the reported bioelectrocatalytic system is attractive for advanced biosensors, as well as for biofuel cells.
Koun Lim, Y. Lee, Olja Simoska et al.
ACS Applied Materials & Interfaces · 2021
Over the past two decades, the designs of redox polymers have become critical to the field of mediated bioelectrocatalysis and are used in commercial glucose biosensors, as well as other bioelectrochemical applications (e.g., energy harvesting). These polymers are specifically used to immobilize redox mediators on electrode surfaces, allowing for self-exchange-based conduction of electrons from enzymes far from the electrode to the electrode surface. However, the synthesis of redox polymers is challenging and results in large batch-to-batch variability. Herein, we report a rapid entrapment of mediators for NAD+-dependent bioelectrocatalysis within reverse ionically condensed polyelectrolytes. A high ionic strength aqueous solution of oppositely charged polyelectrolytes, composed of cationic polyguanidinium (PG) chloride and anionic sodium hexametaphosphate (P6), undergoes phase inversion into a solid microporous polyelectrolyte complex (PEC) when introduced into a low ionic strength aqueous solution. The ionic strength-triggered phase inversion of PGP6 solutions was investigated as a means to entrap mediators on the surface of electrodes for mediated bioelectrocatalysis. Compared to the traditional cross-linked immobilizations using redox polymers, this phase inversion takes place within seconds and requires up to 60 min for complete stabilization. In this work, redox mediator phenazine ethosulfate (PES) was entrapped within PGP6 on electrode surfaces for nicotinamide adenine dinucleotide (NAD+)-dependent bioelectrocatalysis. In the bulk solution, NAD+-dependent dehydrogenase enzymes catalyze the oxidation of the substrate while reducing NAD to reduced nicotinamide adenine dinucleotide (NADH). The resulting NADH is reoxidized to NAD+ by the entrapped PES that gets reduced on the electrode, completing the NAD+-regeneration-based bioelectrocatalysis. To show the use of these new materials in an application, biofuel cells were evaluated using four different anodic enzyme systems (alcohol dehydrogenase, lactate hydrogenase, glycerol dehydrogenase, and glucose dehydrogenase).
Esther Edwardes Moore, Samuel J. Cobb, A. Coito et al.
· 2021
Significance Enzyme bioelectrochemistry concerns the integration of oxidoreductase enzymes into electrodes to enable and study the transfer of electrons between the solid-state material surface and the biological catalyst. To achieve higher enzyme loading, and hence greater current densities, high-surface-area strategies have been employed to immobilize enzymes, but these porous electrode architectures amplify the formation of local chemical gradients. Enzyme selectivity and activity is highly dependent on such changes in local environment, such as substrate concentration, pH, and electrolyte species concentration. Here, electrochemistry and computational techniques are applied to explore, and hence optimize, the local environment of the fuel-producing oxidoreductases, hydrogenase and formate dehydrogenase, within porous electrodes. Bioelectrochemistry employs an array of high-surface-area meso- and macroporous electrode architectures to increase protein loading and the electrochemical current response. While the local chemical environment has been studied in small-molecule and heterogenous electrocatalysis, conditions in enzyme electrochemistry are still commonly established based on bulk solution assays, without appropriate consideration of the nonequilibrium conditions of the confined electrode space. Here, we apply electrochemical and computational techniques to explore the local environment of fuel-producing oxidoreductases within porous electrode architectures. This improved understanding of the local environment enabled simple manipulation of the electrolyte solution by adjusting the bulk pH and buffer pKa to achieve an optimum local pH for maximal activity of the immobilized enzyme. When applied to macroporous inverse opal electrodes, the benefits of higher loading and increased mass transport were employed, and, consequently, the electrolyte adjusted to reach −8.0 mA ⋅ cm−2 for the H2 evolution reaction and −3.6 mA ⋅ cm−2 for the CO2 reduction reaction (CO2RR), demonstrating an 18-fold improvement on previously reported enzymatic CO2RR systems. This research emphasizes the critical importance of understanding the confined enzymatic chemical environment, thus expanding the known capabilities of enzyme bioelectrocatalysis. These considerations and insights can be directly applied to both bio(photo)electrochemical fuel and chemical synthesis, as well as enzymatic fuel cells, to significantly improve the fundamental understanding of the enzyme–electrode interface as well as device performance.
Taiki Makizuka, K. Sowa, O. Shirai et al.
Analytical Sciences · 2022
In enzyme-based biosensors, Ag+ eluted from the reference electrode inhibits the enzyme activity. Herein, to suppress the inhibition of bilirubin oxidase (BOD) by Ag+, kinetic analysis was used to examine the effect of Ag+ on the activity of BOD. It was confirmed that the addition of Ag+ decreased the bioelectrocatalytic activity of BOD. Atomic absorption spectroscopy (AAS) suggested that Ag+ was attached to BOD. Moreover, the changes in the visible absorption spectra after Ag+ addition showed that Ag+ was bound to the type I Cu sites in BOD. During oxygen reduction by BOD, the direct-electron-transfer-type bioelectrocatalytic current decreased after Ag+ was added. The decay of the catalytic current was evaluated using kinetic analysis (assuming a pseudo-first-order reaction). Based on the analysis, the inhibition of BOD was suppressed when the Ag+ concentration was below 0.1 µM. Referring to the solubility product of AgCl, Cl− at a concentration of 1 mM suppressed the inhibition of the enzymatic activity by 95%.
N. Karimian, P. Hashemi, A. Khanmohammadi et al.
Analytical and bioanalytical chemistry research · 2020
Bioelectrocatalysis is a phenomenon concerned with biological catalysts, which accelerate the electrochemical reactions. Bioelectrocatalysis has been widely explored by the research community in various directions. Enzymes can catalyze different chemical reactions in living organisms by enzymes as the most important biological catalysts. These enzymatic biocatalysts are commercially available and commonly called enzyme electrodes. Electron transfer between the active center of the enzyme and the electrode can be performed either by direct electron transfer (DET) or by means of mediators (i.e. mediated electron transfer (MET)), which are discussed in details in the presented review. Therefore, different strategies have been used to increase the efficiency and stability of bioelectrocatalysis. In this review, different strategies of the bioelectrode designs have been discussed and the application of the common bioelectrodes used in the biosensors have been presented in the various fields. Moreover, a summary of the research status in the applications of bioelectrocatalysis in biosensors and biofuel cells was provided.
Xiaoti Yang, Wenjie Wu, Xiling Chen et al.
Science Advances · 2022
Artificial metalloenzymes (ArMs) are commonly designed with protein scaffolds containing buried coordination pockets to achieve substrate specificity and product selectivity for homogeneous reactions. However, their reactivities toward heterogeneous transformations are limited because interfacial electron transfers are hampered by the backbone shells. Here, we introduce bacterial small laccase (SLAC) as a new protein scaffold for constructing ArMs to directly catalyze electrochemical transformations. We use molecular dynamics simulation, x-ray crystallography, spectroscopy, and computation to illustrate the scaffold-directed assembly of an oxo-bridged dicobalt motif on protein surface. The resulting ArM in aqueous phase catalyzes electrochemical water oxidation without mediators or electrode modifications. Mechanistic investigation reveals the role of SLAC scaffold in defining the four-electron transfer pathway from water to oxygen. Furthermore, we demonstrate that SLAC-based ArMs implemented with Ni2+, Mn2+, Ru3+, Pd2+, or Ir3+ also enable direct bioelectrocatalysis of water electrolysis. Our study provides a versatile and generalizable route to complement heterogeneous repertoire of ArMs for expanded applications.
Y. Lee, Koun Lim, S. Minteer
Annual Review of Physical Chemistry · 2021
Enzyme cascades are plentiful in nature, but they also have potential in artificial applications due to the possibility of using the target substrate in biofuel cells, electrosynthesis, and biosensors. Cascade reactions from enzymes or hybrid bioorganic catalyst systems exhibit extended substrate range, reaction depth, and increased overall performance. This review addresses the strategies of cascade biocatalysis and bioelectrocatalysis for (a) CO2 fixation, (b) high value-added product formation, (c) sustainable energy sources via deep oxidation, and (d) cascaded electrochemical enzymatic biosensors. These recent updates in the field provide fundamental concepts, designs of artificial electrocatalytic oxidation-reduction pathways (using a flexible setup involving organic catalysts and engineered enzymes), and advances in hybrid cascaded sensors for sensitive analyte detection. Expected final online publication date for the Annual Review of Physical Chemistry, Volume 72 is April 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.