Discover insights from thousands of peer-reviewed papers on microbial electrochemical systems
Yonggang Wang, Yanfang Song, Yongyao Xia
Chemical Society Reviews · 2016
Electrochemical capacitors (i.e. supercapacitors) include electrochemical double-layer capacitors that depend on the charge storage of ion adsorption and pseudo-capacitors that are based on charge storage involving fast surface redox reactions. The energy storage capacities of supercapacitors are several orders of magnitude higher than those of conventional dielectric capacitors, but are much lower than those of secondary batteries. They typically have high power density, long cyclic stability and high safety, and thus can be considered as an alternative or complement to rechargeable batteries in applications that require high power delivery or fast energy harvesting. This article reviews the latest progress in supercapacitors in charge storage mechanisms, electrode materials, electrolyte materials, systems, characterization methods, and applications. In particular, the newly developed charge storage mechanism for intercalative pseudocapacitive behaviour, which bridges the gap between battery behaviour and conventional pseudocapacitive behaviour, is also clarified for comparison. Finally, the prospects and challenges associated with supercapacitors in practical applications are also discussed.
Lei Zhao, Yuan Li, Meimei Yu et al.
Advanced Science · 2023
The electrolyte‐wettability of electrode materials in liquid electrolytes plays a crucial role in electrochemical energy storage, conversion systems, and beyond relied on interface electrochemical process. However, most electrode materials do not have satisfactory electrolyte‐wettability for possibly electrochemical reaction. In the last 30 years, there are a lot of literature have directed at exploiting methods to improve electrolyte‐wettability of electrodes, understanding basic electrolyte‐wettability mechanisms of electrode materials, exploring the effect of electrolyte‐wettability on its electrochemical energy storage, conversion, and beyond performance. This review systematically and comprehensively evaluates the effect of electrolyte‐wettability on electrochemical energy storage performance of the electrode materials used in supercapacitors, metal ion batteries, and metal‐based batteries, electrochemical energy conversion performance of the electrode materials used in fuel cells and electrochemical water splitting systems, as well as capacitive deionization performance of the electrode materials used in capacitive deionization systems. Finally, the challenges in approaches for improving electrolyte‐wettability of electrode materials, characterization techniques of electrolyte‐wettability, as well as electrolyte‐wettability of electrode materials applied in special environment and other electrochemical systems with electrodes and liquid electrolytes, which gives future possible directions for constructing interesting electrolyte‐wettability to meet the demand of high electrochemical performance, are also discussed.
Guoping Wang, Lei Zhang, Jiujun Zhang
Chem. Soc. Rev. · 2012
In this critical review, metal oxides-based materials for electrochemical supercapacitor (ES) electrodes are reviewed in detail together with a brief review of carbon materials and conducting polymers. Their advantages, disadvantages, and performance in ES electrodes are discussed through extensive analysis of the literature, and new trends in material development are also reviewed. Two important future research directions are indicated and summarized, based on results published in the literature: the development of composite and nanostructured ES materials to overcome the major challenge posed by the low energy density of ES (476 references).
Jie Wu, Hong Liu, Weiwei Chen et al.
Nature Reviews Bioengineering · 2023
Electrochemical biosensors incorporate a recognition element and an electronic transducer for the highly sensitive detection of analytes in body fluids. Importantly, they can provide rapid readouts and they can be integrated into portable, wearable and implantable devices for point-of-care diagnostics; for example, the personal glucose meter enables at-home assessment of blood glucose levels, greatly improving the management of diabetes. In this Review, we discuss the principles of electrochemical biosensing and the design of electrochemical biosensor devices for health monitoring and disease diagnostics, with a particular focus on device integration into wearable, portable and implantable systems. Finally, we outline the key engineering challenges that need to be addressed to improve sensing accuracy, enable multiplexing and one-step processes, and integrate electrochemical biosensing devices in digital health-care pathways. Electrochemical biosensors can be integrated into wearable, portable and implantable devices for health monitoring and disease diagnosis. This Review discusses the design and integration of different types of electrochemical biosensors for the detection of analytes related to health and disease, and outlines engineering challenges that need to be addressed to enable clinical translation of electrochemical biosensor-based point-of-care devices. Electrochemical biosensors are self-contained, analytical devices, in which a biological recognition element is in direct contact with an electrochemcial transduction element to allow the sensitive and specific detection of analytes. Depending on the design and sensor type, health-related and disease-related biomarkers, such as carbohydrates, proteins, nucleic acids and cells, can be rapidly analysed in different body fluids, including blood, saliva and tears. Electrochemical biosensors, including amperometric, voltammetric, potentiometric, organic electrochemical transistor, photoelectrochemical and electrochemiluminescent sensors, can be integrated into wearable, portable and implantable devices to enable point-of-care diagnostics and health monitoring. Commercialization and broad point-of-care applicability of integrated electrochemical biosensors will require improvements in stability, sensitivity, reproducibility, multiplexing, and digitalization and, importantly, low-cost materials and easy fabrication methods. Electrochemical biosensors are self-contained, analytical devices, in which a biological recognition element is in direct contact with an electrochemcial transduction element to allow the sensitive and specific detection of analytes. Depending on the design and sensor type, health-related and disease-related biomarkers, such as carbohydrates, proteins, nucleic acids and cells, can be rapidly analysed in different body fluids, including blood, saliva and tears. Electrochemical biosensors, including amperometric, voltammetric, potentiometric, organic electrochemical transistor, photoelectrochemical and electrochemiluminescent sensors, can be integrated into wearable, portable and implantable devices to enable point-of-care diagnostics and health monitoring. Commercialization and broad point-of-care applicability of integrated electrochemical biosensors will require improvements in stability, sensitivity, reproducibility, multiplexing, and digitalization and, importantly, low-cost materials and easy fabrication methods.
A. Lazanas, M. Prodromidis
ACS Measurement Science Au · 2023
This tutorial provides the theoretical background, the principles, and applications of Electrochemical Impedance Spectroscopy (EIS) in various research and technological sectors. The text has been organized in 17 sections starting with basic knowledge on sinusoidal signals, complex numbers, phasor notation, and transfer functions, continuing with the definition of impedance in electrical circuits, the principles of EIS, the validation of the experimental data, their simulation to equivalent electrical circuits, and ending with practical considerations and selected examples on the utility of EIS to corrosion, energy related applications, and biosensing. A user interactive excel file showing the Nyquist and Bode plots of some model circuits is provided in the Supporting Information. This tutorial aspires to provide the essential background to graduate students working on EIS, as well as to endow the knowledge of senior researchers on various fields where EIS is involved. We also believe that the content of this tutorial will be a useful educational tool for EIS instructors.
V. Augustyn, P. Simon, B. Dunn
Energy & Environmental Science · 2014
Electrochemical energy storage technology is based on devices capable of exhibiting high energy density (batteries) or high power density (electrochemical capacitors). There is a growing need, for current and near-future applications, where both high energy and high power densities are required in the same material. Pseudocapacitance, a faradaic process involving surface or near surface redox reactions, offers a means of achieving high energy density at high charge–discharge rates. Here, we focus on the pseudocapacitive properties of transition metal oxides. First, we introduce pseudocapacitance and describe its electrochemical features. Then, we review the most relevant pseudocapacitive materials in aqueous and non-aqueous electrolytes. The major challenges for pseudocapacitive materials along with a future outlook are detailed at the end.
Shuang Guo, Wan Qian Guo, Yuan Yuan et al.
Advanced Materials Research · 2013
Anaerobic biological technology and bioelectrochemical technology are regarded as promising sustainable wastes treatment processes. With biocatalysis in BESs anode or cathode, various pollutants can be removed. The pollutants range from nitrogen and sulfur to complex compounds. However, the investigation on recalcitrant wastes removal with biocathode has only been reported recently. Recalcitrant wastes, especially chlorinated nitroaromatic compounds, are highly persistent and toxic environmental pollutions which should be removed before discharging to environment. This paper provides a review on anaerobic biocathode BESs for recalcitrant wastes treatment and the feasibility of this system for CANs transformation. It is expected that anaerobic biocathode BESs can provide an appropriate condition for these compounds to transform to easily degradable forms. The technical challenges for future research are also discussed.
O. Lefebvre, A. Al-Mamun, H. Y. Ng
Water Science and Technology · 2008
Microbial fuel cells (MFCs) are a promising anaerobic technology but they are limited by the high cost of the catalyst used at the cathode (typically platinum). In this study, we designed a novel type of two-chambered MFC wherein an autoheterotrophic denitrifying biofilm replaced the costly catalyst on the cathode surface. Micro-organisms performed denitrification by using electrons supplied by bacteria oxidizing domestic wastewater and acetate as substrates in the anode chamber. This two-chambered MFC equipped with a biocathode generated during more than 1.5 month up to 9.4 mW m−2 of anode surface or 0.19 W m−3 of anode chamber volume, while removing over 65% of COD, 84% of total nitrogen and nearly 30% of suspended solids with domestic wastewater as a substrate, and nearly 95% of acetate in the subsequent experiments.
Varun Srinivasan, Jacob Weinrich, Caitlyn Butler
Environmental Science: Water Research & Technology · 2016
This study presents the conditions of nitrite accumulation in MFC biocathodes through batch experiments and derives kinetic parameters with an Activated Sludge Model with an integration of the Nernst–Monod model and Indirect Coupling of Electrons (ASM–NICE).
Mohita Sharma, Priyangshu M. Sarma, Deepak Pant et al.
RSC Advances · 2015
This study focuses on the effect of operational and physiochemical factors on a stable sulfate reducing bacteria biocathode and their effect on the electrochemical response thereof.
Caitlyn Shea, Peter Clauwaert, Willy Verstraete et al.
Water Science and Technology · 2008
Perchlorate is widely used as a propellant in the aerospace and defense industries, and is of environmental concern due to its high mobility and inhibiting effect on thyroid function. An ideal treatment approach is bioreduction to chloride via dissimilatory perchlorate-reducing bacteria (PCRB). PCRB are ubiquitous in the environment, and are mainly facultative anaerobes and denitrifiers. Previous research suggests that PCRB may grow using a cathode as an electron donor, although this research was performed in a half cell with exogenous electron shuttles. We investigated a functioning MFC with a denitrifying biocathode for perchlorate reduction, as a means to confirm the existence of biocathode-utilizing PCRB and the possibility of perchlorate remediation without added shuttles. The biocathode was initially run with 20 mgN/L nitrate. The perchlorate concentration was increased stepwise from 0.1 mg/L to 20 mg/L, while the nitrate concentration was decreased from 20 mgN/L to 5 mgN/L. The maximum perchlorate removal was 12 mg/L-d, contributing 64% to the 0.28 mA produced by the cell. Given the lack of soluble electron donor in the medium, the extent of perchlorate reduction, and the improvement of perchlorate reduction over time, these tests strongly suggest PCRB are utilizing the cathode as an electron donor without exogenous electron shuttles.
Yue Du, Youpeng Qu, Xiangtong Zhou et al.
RSC Advances · 2015
Biocathode coupled photoelectrochemical cells (Bio-PEC) have the potential for electricity generation and pollutant removal, with the simultaneous utilization of both solar energy and bioenergy.
Moustafa Almunla, Yudum Tepeli Büyüksünetçi, Oğuz Akpolat et al.
Electroanalysis · 2021
Abstract A biofuel cell (BFC) was fabricated by combining multiwalled carbon nanotube ‐platinum‐gold (MWCNT−Pt−Au) hybrid nanomaterial, glucose oxidase (GOx) and benzoquinone included carbon felt electrode (CFE) bioanode with apple tissue included CFE biocathode. The working parameters of bioanode were optimized both experimentally and chemometrically. For the biocathode, apple, banana and pear tissues were tried and best power output was obtained with apple tissue. By combining MWCNT−Pt−Au/GOx/CFE bioanode with apple tissue based biocathode, single cell, double cell with membrane and with salt‐bridge BFCs were formed. The best power output with highest current density were obtained with single cell BFC.
Tahsin Bahar
Asia-Pacific Journal of Chemical Engineering · 2016
Abstract Ferrocene groups introduced polyethylenimine was adsorbed onto multi‐wall carbon nanotubes attached carbon cloth before crosslinking via glutaraldehyde to develop an enzyme electrode (anode) for biofuel cell applications. Glucose oxidase was covalently immobilized onto this electrode by leftover aldehyde groups on the surface. The apparent Michaelis constant of immobilized enzyme was measured as approximately fivefold higher than that of the free enzyme. Thermal stability of immobilized enzyme was improved as estimated. Activity half‐life of the immobilized glucose oxidase was determined as approximately 8 times longer than that of the free one; 2.4 mA/cm 2 electrical current was obtained by using this electrode by forming a basic biofuel half‐cell. Copyright © 2016 Curtin University of Technology and John Wiley & Sons, Ltd.
Aya Kontani, Miyuki Masuda, Hirotoshi Matsumura et al.
Electroanalysis · 2014
Abstract To extend the range of biofuel cell applications, we wish to increase their maximum operational temperatures. Using a thermostable alcohol dehydrogenase as a biocatalyst, we prepared an enzyme‐immobilized bioanode that can operate at high temperatures. The catalytic current for ethanol oxidation was increased using this electrode at temperatures up to 80 °C.
Jérémie-Luc Sanchez, Christel Laberty-Robert
Journal of Materials Chemistry B · 2021
A microbial fuel cell bioanode encapsulating electroactive bacteria in core–shell fibers mixed with a conductive scaffold was electrospun. This new design opens up perspectives of storable ready-to-use anodes for portable applications.
Yuhe Shi, Lin Li, Ling Zhang
Electroanalysis · 2022
Abstract Herein, we successfully construct the 3D biocompatible graphene through crosslinking 2D graphene nanosheet onto carbon fiber paper with poly(diallyldimethylammonium chloride) (PDDA) as anode of the alcohol biofuel cell. Compared with the bioanode without 3D graphene, the current density and output power of PDDA‐graphene‐ADH bioanode is increased by 23 % and 41 % at a high concentration of ethanol at pH 8.9, suggesting the stabilization role of graphene in enzyme loading. The study provides us a deep analysis on structures and performances of the bioanode incl. electrochemistry, X‐ray photoelectron spectra, and atomic force microscopy images, which is significant to develop the new methods to construct 3D porous electrodes in energy conversion device.
Yuki Sakurada, Kouta Takeda, Hiroyuki Ohno et al.
Catalysts · 2017
A bioanode for ethanol oxidation was prepared by immobilizing the recombinant pyrroloquinoline quinone (PQQ)-dependent alcohol dehydrogenase from Pseudomonas putida KT 2440 (PpADH) with polyion complex (PIC) and redox polymer. The PIC based on poly-l-lysine (PLL) and poly-l-glutamic acid (PGA) was suitable for immobilizing PpADH on the electrode. PpADH was immobilized using only one redox polymer, aminoferrocene, which was attached to the PGA backbone (PGA-AmFc) on the electrode. The anodic current density at 0.6 V (vs. Ag/AgCl) was 22.6 μA·cm−2. However, when the number of the cycles was increased, the catalytic current drastically decreased. PpADH was immobilized using PGA-AmFc and PIC on the electrode. The anodic current density at 0.5 V (vs. Ag/AgCl) was 47.3 μA·cm−2, and the performance maintained 74% of the initial value after five cycles. This result indicated that the combination of PIC and PGA-AmFc was suitable for the immobilization of PpADH on the electrode. In addition, the long-term stability and catalytic current density were improved by using the large surface area afforded by the gold nanoparticles.
Tomohiro Komatsu, Kazuki Hishii, Michiko Kimura et al.
International Journal of Molecular Sciences · 2021
With the rapid decline of fossil fuels, various types of biofuel cells (BFCs) are being developed as an alternative energy source. BFCs based on multi-enzyme cascade reactions are utilized to extract more electrons from substrates. Thus, more power density is obtained from a single molucule of substrate. In the present study, a bioanode that could extract six electrons from a single molecule of L-proline via a three-enzyme cascade reaction was developed and investigated for its possible use in BFCs. These enzymes were immobilized on the electrode to ensure highly efficient electron transfer. Then, oriented immobilization of enzymes was achieved using two types of self-assembled monolayers (SAMs). In addition, a microfluidic system was incorporated to achieve efficient electron transfer. The microfluidic system, in which the electrodes were arranged in a tooth-shaped comb, allowed for substrates to be supplied continuously to the cascade, which resulted in smooth electron transfer. Finally, we developed a high-performance bioanode which resulted in the accumulation of higher current density compared to that of a gold disc electrode (205.8 μA cm−2: approximately 187 times higher). This presents an opportunity for using the bioanode to develop high-performance BFCs in the future.
Bongkyu Kim, Junyeong An, In Seop Chang
ChemSusChem · 2017
Abstract The power overshoot generated by electron depletion in microbial fuel cells (MFCs) was characterized in this study. Various causes of power overshoot, identified in previous studies, are discussed in terms of their plausible contributions to electron depletion. We found that power overshoot occurred if the anodic overpotential generated by electron depletion exceeded the cathodic overpotential. The introduction of assistance current from anode connections, which ameliorated the electron depletion in the MFCs, immediately eliminated the power overshoot. As a result, if the electron production at the anode exceeded electron reduction at the cathode, a power overshoot was not generated. The results revealed that introducing assistance current supplied from an additional anode to the limited anode eliminated power overshoot. The power overshoot is not generated by kinetic limitation at the cathode; it is only generated by the kinetic limitation at the anode. The mechanism underlying power overshoot should be considered in the design of MFCs to improve reliability, particularly in scaled‐up plant applications. The proposed technique is more practical than previously proposed methods.
Yuanyuan Zhang, Mary Arugula, Shannon Williams et al.
ECS Transactions · 2015
We report here a novel layer-by-layer (LbL) assembled enzyme cascade bioanode incorporated with CNT-invertase and CNT-glucose dehydrogenase for sucrose oxidation in a biofuel cell. Methylene green (MG) was used as redox mediator for electrocatalytic oxidation of NADH at reduced overpotentials on screen printed electrode (SPE). The LbL architecture showed advantages for sequential enzymatic reaction that favored the efficient penetration of substrate and products in a cascade system. The maximum current density and power density achieved were 412 ± 36 μA/cm 2 and 85±6μW/cm 2 .The high current density/power density obtained showed LbL assembly is of great advantage and can be employed as a simple and efficient way to construct enzyme cascade bioanode for biofuel cell applications.
T. Matsumoto, S. Shimada, K. Yamamoto et al.
Fuel Cells · 2013
Abstract The present study reports the design of a novel bioanode to deeply oxidize glucose in an enzymatic biofuel cell (EFC). This enzymatic glucose cell utilizes three co‐immobilized enzymes: NAD‐dependent glucose dehydrogenase (GDH), NAD(P) + ‐dependent gluconate‐5‐dehydrogenase (Ga5DH), and diaphorase (DI). Glucose is oxidized to gluconate by NAD‐dependent GDH, gaining two electrons per glucose; the gluconate obtained as a by‐product is oxidized at the C5 carbon to 5‐keto‐gluconate by Ga5DH. Operation of our bioanode enabled the oxidation of glucose in two stages, resulting in the gain of four electrons. The three‐enzyme EFC provides a maximum power density of 10.51 ± 1.72 μW cm –2 , which is about 1.6 times higher than the maximum power density of an EFC using a bioanode based on the co‐immobilization of two enzymes (GDH and DI). Our results hold promise for increasing the current density of EFCs, and for application in glucose biosensor.
Roman Chomicz, Michał Bystrzejewski, Krzysztof Stolarczyk
Catalysts · 2021
This work demonstrates the application of magnetic carbon-encapsulated iron nanoparticles (CEINs) for the construction of bioelectrodes in a biobattery and a biofuel cell. It has been shown that carbon-encapsulated iron nanoparticles are a suitable material for the immobilization of laccase (Lc) and 1,4-naphthoquinone (NQ) and fructose dehydrogenase (FDH). The system is stable; no leaching of the enzyme and mediator from the surface of the modified electrode was observed. The onset of the catalytic reduction of oxygen to water was at 0.55 V, and catalytic fructose oxidation started at −0.15 V. A biobattery was developed in which a zinc plate served as the anode, and the cathode was a glassy carbon electrode modified with carbon-encapsulated iron nanoparticles, laccase in the Nafion (Nf) layer. The maximum power of the cell was ca. 7 mW/cm2 at 0.71 V and under external resistance of 1 kΩ. The open-circuit voltage (OCV) for this system was 1.51 V. In the biofuel cell, magnetic nanoparticles were used both on the bioanode and biocathode to immobilize the enzymes. The glassy carbon bioanode was coated with carbon-encapsulated iron nanoparticles, 1,4-naphthoquinone, fructose dehydrogenase, and Nafion. The cathode was modified with carbon-encapsulated magnetic nanoparticles and laccase in the Nafion layer. The biofuel cell parameters were as follows: maximum power of 78 µW/cm2 at the voltage of 0.33 V and under 20 kΩ resistance, and the open-circuit voltage was 0.49 V. These enzymes worked effectively in the biofuel cell, and laccase also effectively worked in the biobattery.
Longfei Sun, Xiaohua Zhang, Wenyang Wang et al.
Analytical Methods · 2015
An easy-operation and high-performance bioanode based on a composite gel of ferrocenecarboxaldehyde modified CNTs and an ionic liquid was successfully developed.
Zonghua Wang, Lin Xia, Jianfei Xia et al.
RSC Advances · 2016
A hybrid anode integrating enzymatic hydrolysis of starch by glucoamylase and non-enzymatic oxidation of glucose by gold nanoparticles is presented to achieve an efficient cascade energy conversion from starch.
Ting‐Ting Zhu, Zhou‐Hua Cheng, Sheng‐Song Yu et al.
Environmental Microbiology · 2022
Summary Exoelectrogenic bacteria (EEB) are capable of anaerobic respiration with diverse extracellular electron acceptors including insoluble minerals, electrodes and flavins, but the detailed electron transfer pathways and reaction mechanisms remain elusive. Here, we discover that CymA, which is usually considered to solely serve as an inner‐membrane electron transfer hub in Shewanella oneidensis MR‐1 (a model EEB), might also function as a reductase for direct reducing diverse nitroaromatic compounds (e.g. 2,4‐dichloronitrobenzene) and azo dyes. Such a process can be accelerated by dosing anthraquinone‐2,6‐disulfonate. The CymA‐based reduction pathways in S . oneidensis MR‐1 for different contaminants could be functionally reconstructed and strengthened in Escherichia coli . The direct reduction of lowly polar contaminants by quinol oxidases like CymA homologues might be universal in diverse microbes. This work offers new insights into the pollutant reduction mechanisms of EEB and unveils a new function of CymA to act as a terminal reductase.
Edgar Ribot‐Llobet, Nuria Montpart, Yolanda Ruiz‐Franco et al.
Journal of Chemical Technology & Biotechnology · 2014
Abstract BACKGROUND The microbial fuel cell ( MFC ) technology transforms the chemical energy present in substrates into electricity. Starting‐up these systems, i.e. enriching the anodic community in exoelectrogenic bacteria, is a lengthy process or requires expensive equipment. RESULTS An easy and low‐cost procedure based on a sediment MFC was developed to select microbial communities with exoelectrogenic activity from the anaerobic sludge of a waste water treatment plant ( WWTP ). The configuration was based on a simple vessel working as a single chamber MFC with a cathode of stainless steel wool in the liquid surface and a submerged graphite fibre brush as anode. In 30 days of operation, a biofilm with remarkable exoelectrogenic activity was grown on the anode of the MFC . This graphite fibre brush anode was able to supply 0.9 W m ‐2 when working in an air‐cathode MFC ( AC‐MFC ) for 45 days. CONCLUSION The procedure presented was demonstrated to be a successful, low‐cost and low‐maintenance procedure to obtain exoelectrogenic activity and had performances comparable with other more costly and complex inoculation procedures. The Sed‐ MFC does not require a potentiostat, external aeration, stirring, membranes or an enriched inoculum in the exoelectrogenic biomass. © 2013 Society of Chemical Industry
Michael Lienemann, Michaela A. TerAvest, Juha‐Pekka Pitkänen et al.
Microbial Biotechnology · 2018
Summary Biosensors detect signals using biological sensing components such as redox enzymes and biological cells. Although cellular versatility can be beneficial for different applications, limited stability and efficiency in signal transduction at electrode surfaces represent a challenge. Recent studies have shown that the Mtr electron conduit from Shewanella oneidensis MR ‐1 can be produced in Escherichia coli to generate an exoelectrogenic model system with well‐characterized genetic tools. However, means to specifically immobilize this organism at solid substrates as electroactive biofilms have not been tested previously. Here, we show that mannose‐binding Fim pili can be produced in exoelectrogenic E. coli and can be used to selectively attach cells to a mannose‐coated material. Importantly, cells expressing fim genes retained current production by the heterologous Mtr electron conduit. Our results demonstrate the versatility of the exoelectrogenic E. coli system and motivate future work that aims to produce patterned biofilms for bioelectronic devices that can respond to various biochemical signals.
G. Pasternak, T. D. Askitosari, M. Rosenbaum
Frontiers in Microbiology · 2020
Bioelectrochemical systems (BESs) are ruled by a complex combination of biological and abiotic factors. The interplay of these factors determines the overall efficiency of BES in generating electricity and treating waste. The recent progress in bioelectrochemistry of BESs and electrobiotechnology exposed an important group of compounds, which have a significant contribution to operation and efficiency: surface-active agents, also termed surfactants. Implementation of the interfacial science led to determining several effects of synthetic and natural surfactants on BESs operation. In high pH, these amphiphilic compounds prevent the cathode electrodes from biodeterioration. Through solubilization, their presence leads to increased catabolism of hydrophobic compounds. They interfere with the surface of the electrodes leading to improved biofilm formation, while affecting its microarchitecture and composition. Furthermore, they may act as quorum sensing activators and induce the synthesis of electron shuttles produced by electroactive bacteria. On the other hand, the bioelectrochemical activity can be tailored for new, improved biosurfactant production processes. Herein, the most recent knowledge on the effects of these promising compounds in BESs is discussed.
L. Bird, R. Mickol, Brian J. Eddie et al.
Microbial Biotechnology · 2022
The junction of bioelectrochemical systems and synthetic biology opens the door to many potentially groundbreaking technologies. When developing these possibilities, choosing the correct chassis organism can save a great deal of engineering effort and, indeed, can mean the difference between success and failure. Choosing the correct chassis for a specific application requires a knowledge of the metabolic potential of the candidate organisms, as well as a clear delineation of the traits, required in the application. In this review, we will explore the metabolic and electrochemical potential of a single genus, Marinobacter. We will cover its strengths, (salt tolerance, biofilm formation and electrochemical potential) and weaknesses (insufficient characterization of many strains and a less developed toolbox for genetic manipulation) in potential synthetic electromicrobiology applications. In doing so, we will provide a roadmap for choosing a chassis organism for bioelectrochemical systems.
Eric M. Conners, K. Rengasamy, A. Bose
Journal of Industrial Microbiology and Biotechnology · 2022
Abstract Microbial biofilms are ubiquitous. In marine and freshwater ecosystems, microbe–mineral interactions sustain biogeochemical cycles, while biofilms found on plants and animals can range from pathogens to commensals. Moreover, biofouling and biocorrosion represent significant challenges to industry. Bioprocessing is an opportunity to take advantage of biofilms and harness their utility as a chassis for biocommodity production. Electrochemical bioreactors have numerous potential applications, including wastewater treatment and commodity production. The literature examining these applications has demonstrated that the cell–surface interface is vital to facilitating these processes. Therefore, it is necessary to understand the state of knowledge regarding biofilms’ role in bioprocessing. This mini-review discusses bacterial biofilm formation, cell–surface redox interactions, and the role of microbial electron transfer in bioprocesses. It also highlights some current goals and challenges with respect to microbe-mediated bioprocessing and future perspectives.
Yue Wang, Yijing Gao, Xueqin Lu et al.
SSRN Electronic Journal · 2023
The disintegration of anaerobic sludge and blockage of membrane pores has impeded the practical application of anaerobic membrane bioreactor (AnMBR) in treating methanolic wastewater. In this study, bioelectrochemical system (BES) was integrated into AnMBR to alleviate sludge dispersion and membrane fouling as well as enhance bioconversion of methanol. Bioelectrochemical regulation effect induced by BES enhanced methane production rate from 4.94 ± 0.52 to 5.39 ± 0.37 L/Lreactor/d by accelerating the enrichment of electroactive microorganisms and the agglomeration of anaerobic sludge via the adhesive and chemical bonding force. 16 S rRNA gene high-throughput sequencing demonstrated that bioelectrochemical stimulation had modified the metabolic pathways by regulating the key functional microbial communities. Methanogenesis via the common methylotrophic Methanomethylovorans was partially substituted by the hydrogenotrophic Candidatus_Methanofastidiosum, etc. The metabolic behaviors of methanol are bioelectrochemistry-dependent, and controlling external voltage is thus an effective strategy for ensuring robust electron transfer, low membrane fouling, and long-term process stability.
Han Chen, Yu-Qing Wei, Meng-Yuan Xu et al.
Small · 2024
Bioelectrochemical reactions using whole-cell biocatalysts are promising carbon-neutral approaches because of their easy operation, low cost, and sustainability. Bidirectional (outward or inward) electron transfer via exoelectrogens plays the main role in driving bioelectrochemical reactions. However, the low electron transfer efficiency seriously inhibits bioelectrochemical reaction kinetics. Here, a three dimensional and artificial nanoparticles-constituent inverse opal-indium tin oxide (IO-ITO) electrode is fabricated and employed to connect with exoelectrogens (Shewanella loihica PV-4). The above electrode collected 128-fold higher cell density and exhibited a maximum current output approaching 1.5 mA cm-2 within 24 h at anode mode. By changing the IO-ITO electrode to cathode mode, the exoelectrogens exhibited the attractive ability of extracellular electron uptake to reduce fumarate and 16 times higher reverse current than the commercial carbon electrode. Notably, Fe-containing oxide nanoparticles are biologically synthesized at both sides of the outer cell membrane and probably contributed to direct electron transfer with the transmembrane c-type cytochromes. Owing to the efficient electron exchange via artificial and biosynthetic nanoparticles, bioelectrochemical CO2 reduction is also realized at the cathode. This work not only explored the possibility of augmenting bidirectional electron transfer but also provided a new strategy to boost bioelectrochemical reactions by introducing biohybrid nanoparticles.
L. Caneo, G. Matte, R. Groom et al.
Brazilian Journal of Cardiovascular Surgery · 2019
Luiz Fernando Caneo1, MD, PhD; Gregory Matte2, CCP, LP, FPP; Robert Groom3, PhD; Rodolfo A. Neirotti4, MD, PhD, FEACTS; Paulo Manuel Pêgo-Fernandes5, MD, PhD; Juan Alberto C. Mejia6, MD, PhD; Fernando Augusto Marinho dos Santos Figueira7, MD; Élio Barreto de Carvalho Filho8, MSc; Fábio Murilo da Costa8, Sintya Tertuliano Chalegre9,10, MSc; Renato Abdala Karam Kalil11, MD, MSc, PhD; Rui M. S. Almeida12, MD, MSc, PhD; on behalf of DECAM/SBCCV13 and SBCEC14
Fernando Barcellos da Silva, L. A. Chisini, F. Demarco et al.
Brazilian Oral Research · 2018
Population-based studies estimating the prevalence of tooth bleaching desire or the percentage of individuals who had performed this treatment are rare. Thus, the aim of this study was to evaluate the desire to perform tooth bleaching and the prevalence of adult individuals who had performed the treatment and investigate the association of these outcomes. A subsample (n = 536) of the 1982 Pelotas birth cohort in southern Brazil was investigated at the ages 15, 24 and 31 by clinical examinations and interviews. The prevalence of bleaching at 31 years was 15.6% [95%CI 12.6-18.9] while 85.9% [95%CI 82.7-88.7] reported they desired the treatment. Multivariate Poisson regression analysis showed that individuals who have visited the dentist within the last year showed a treatment prevalence ratio (PR) 2.31 times [95%CI 1.40-3.83] higher compared with those who had the last dental visit more than a year before the interview. Similarly, individuals with smoking habits presented an elevated PR of 1.60 [95%CI 1.00-2.55], and the low-income trajectory group showed the largest PR of desire for tooth bleaching (1.17 [95%CI 1.07-1.28]). Moreover, individuals from the high-risk caries trajectory group presented a higher prevalence of desire for tooth bleaching than individuals from low caries trajectory group. Individuals who have declared being "dissatisfied" with their dental color presented a prevalence of desire for tooth bleaching 16% greater than "satisfied" ones. Thus, the present findings confirm that tooth bleaching has become a frequently desired dental treatment to improve dental aesthetics in the population and a considerable rate of adults has performed the treatment.
L. Silva, J. Arruda, Stephanie Joana Roman Martelli et al.
Brazilian Oral Research · 2018
The aim of this study was to investigate the prevalence of oral and maxillofacial lesions among children from representative regions of Brazil. A retrospective descriptive study was conducted. Biopsy records comprising the period from 2000 to 2015 were obtained from the archives of three Brazilian oral pathology referral centers. A total of 32,506 biopsy specimens were analyzed, and specimens from 1,706 children aged 0-12 years were selected. Gender, age, anatomical location and histopathological diagnosis were evaluated. Descriptive statistics was carried out. Likelihood ratio tests were used to evaluate the association between the categorical variables. The level of significance was set at 0.05. The post-hoc test was used to identify the subgroups that significantly differed from one another, and the Bonferroni correction was applied. A total of 1,706 oral and maxillofacial lesions were diagnosed in pediatric patients, including 51.9% girls. Oral mucocele was the most prevalent reactive/inflammatory lesion (64%). The most commonly affected sites were the lips (34.5%) and mandible (19.9%). A significant association was observed between age and the group of lesions of the oral cavity (p < 0.001), and between age and anatomical location (p < 0.001). Pediatric oral and maxillofacial lesions were frequent and showed wide diversity, with the prevalence of mucocele. Knowledge of oral lesions is important for pediatric dentists worldwide, since it provides accurate data for the diagnosis and oral health of children.
L. G. Rosenfeld, D. Malta, C. Szwarcwald et al.
Revista Brasileira de Epidemiologia · 2019
OBJECTIVE To describe reference values for blood counts obtained from laboratory tests in the Brazilian adult population according to laboratory results from the National Health Survey (Pesquisa Nacional de Saúde - PNS), by gender, age group and skin color. METHODS The initial sample consisted of 8,952 adults. To determine the reference values, individuals with prior diseases and outliers were excluded. Mean values, standard deviation and limits were stratified by gender, age group and skin color. RESULTS For red blood cells, men presented a mean value of 5.0 million per mm3 (limits: 4.3-5.8) and women, 4.5 million per mm3 (limits: 3.9-5.1). Hemoglobin levels were higher among men with a mean of 14.9 g/dL (13.0-16.9), and in women, 13.2 g/dL (11.5-14.9). The mean number of white blood cells among men was 6.142/mm3 (2.843-9.440) and 6.426/mm3 (2.883-9.969) for women. Other parameters showed close values between the genders. Regarding age groups and skin color, mean values, standard deviation and limits of the exams presented small variations. CONCLUSION Hematological reference values based on the national survey allow for the establishment of specific reference limits for gender, age and skin color. The results presented here may contribute to the establishment of better evidence and criteria for the care, diagnosis and treatment of diseases.
Bingqing Shi, Yuming Zhao, Xiaojing Yuan
Brazilian Oral Research · 2020
The aim of this study was to evaluate the effect of mineral trioxide aggregate (MTA) and Brazilian propolis on the cell viability, mineralization, anti-inflammatory ability, and migration of human dental pulp cells (hDPCs). The cell viability was evaluated with CCK-8 kit after 1, 5, 7, and 9 days. The deposition of calcified matrix and the expression of osteogenesis-related genes were evaluated by Alizarin Red staining and real-time PCR after incubation in osteogenic medium for 21 days. The expression of inflammation-related genes in cells was determined after exposure to 1 μg/mL LPS for 3 h. Finally, the numbers of cells that migrated through the permeable membranes were compared during 15 h. Propolis and MTA significantly increased the viability of hDPCscompared to the control group on days 7 and 9. In the propolis group, significant enhancement of osteogenic potential and suppressed expression of IL-1β and IL-6 was observed after LPS exposure compared to the MTA and control groups. The number of migration cells in the propolis group was similar to that of the control group, while MTA significantly promoted cell migration. Propolis showed comparable cell viability to that of MTA and exhibited significantly higher anti-inflammatory and mineralization promotion effects on hDPCs.
L. Machado
Vibrant: Virtual Brazilian Anthropology · 2020
Abstract The present article discusses the recent neo-conservative movement in Brazil led by the Agribusiness and Evangelical Congressional Caucuses. Both fronts built and consolidated a confluence of objectives and political linkages in the National Congress to confront access to human rights. Neoconservative narratives centered on the “moral agenda” and based on the manipulation of Christian religious values have grown in Brazil’s public scene, countering concepts of gender equality, sexual diversity and reproductive rights. At the same time, an agenda of “legal certainty”, based on the interests of agribusiness, has dismantled environmental protection policies and blocked indigenous and quilombola rights to access land. This movement promotes the delegitimization of anthropological knowledge and of the sciences in general, while undermining the fundamental rights referenced by the Brazilian constitution. With the inauguration of a neoconservative government, intolerance has grown. As Bauman warns, one of the conditions of the dehumanization of the “Other” is authorization by government practices. The challenges facing Brazilian anthropology have increased dramatically in this scenario.
L. F. Zeola, Daniela Navarro Ribeiro Teixeira, Alexia da Mata Galvão et al.
Brazilian Oral Research · 2020
The aim of this study was to investigate how Brazilian dentists perceive and manage dentin hypersensitivity (DH) in their clinical routine. A 13-item questionnaire-based survey was developed and sent electronically to a convenience sample of dentists. The questionnaire assessed the personal and dental practice characteristics of the sample, the occurrence of DH in their daily clinical practice, and management strategies. The data were analyzed descriptively and together with the chi-square test (a = 0.05). A total of 353 responses were obtained from September 2017 to March 2018. Of all the respondents, 62% were females, 49.9% reported fewer than five years of dental practice, and 70.5% were self-identified as private practitioners. Most of the dentists reported an estimated frequency (30-60%) of patients with DH in their practice. The most frequently cited (91.79%) trigger of DH was air blast and/or scratching with a probe. The first-choice strategy to manage DH was a dentin desensitizer (48.16%). The number of years in clinical practice did not influence DH relapse frequency (p = 0.76) significantly, or consider DH treatment as a problem (p = 0.22). The present findings indicate that, regardless of clinical experience, dentists in Brazil still consider DH management a challenge in their daily dental practice. In addition, the results suggest that guidelines should be developed to disseminate the available knowledge regarding this condition in ways that may influence decision-making processes among practitioners.