Research Library

Wulin Yang, Xu Wang, Moon Son et al.

Journal of Power Sources · 2020

Daniel Liu, Jimmy Kuo, Chorng-Horng Lin

Processes · 2024

Certain bacteria can transfer extracellular electrons and are applied in microbial fuel cells (MFCs). In this study, we compared the extracellular electron transfer characteristics of 85 genomes from nine genera, namely Blautia, Bradyrhizobium, Desulfuromonas, Dialister, Geobacter, Geothrix, Shewanella, Sphingomonas, and Phascolarctobacterium, using the bioinformatic tools Prokka 1.14.6, Roary 3.13.0, Panaroo 1.3.4, PEPPAN 1.0.6, and Twilight. The unweighted pair-group method with arithmetic mean (UPGMA) clustering of genes related to extracellular electron transfer revealed a good genus-level structure. The relative abundance and hierarchical clustering analyses performed in this study suggest that the bacteria Desulfuromonas, Geobacter, Geothrix, and Shewanella have more extracellular electron transfer genes and cluster together. Further functional differences among the genomes showed that 66 genes in these bacteria were significantly higher in abundance than in the other five bacteria (p < 0.01) based on PEPPAN followed by a Twilight analysis. Our work provides new potential insights into extracellular electron transfer in microorganisms.

Arpita Bose, Zhecheng Zhang

Open Access Government · 2025

Role of extracellular electron transfer in the nitrogen cycle Extracellular electron transfer impacts the nitrogen cycle by enhancing microbial processes and connecting to other biogeochemical cycles. Understanding EET mechanisms provides insights into ecosystem functioning and potential advancements; Arpita Bose and Zhecheng (Robert) Zhang explain. Nitrogen is a fundamental element required by all living species. It can be found in amino acids, proteins, and nucleic acids. The nitrogen cycle promotes nitrogen transformation and transit across the environment, making it available for biological activity. Key steps in the cycle include nitrogen fixation (conversion of atmospheric nitrogen to ammonia), nitrification (oxidation of ammonia to nitrate), denitrification (reduction of nitrate to nitrogen gas), and anaerobic ammonium oxidation (anammox), which then converts ammonium and nitrite directly to nitrogen gas. Extracellular electron transfer (EET) is the mechanism by which microorganisms transmit electrons from their cells to accept electrons from external donors. This ability allows microorganisms to interact with insoluble substrates, which, in turn, influences a variety of biogeochemical cycles, including the nitrogen cycle. Understanding EET’s function sheds light on microbial ecology and environmental processes.

M. BouDagher-Fadel

UCL Press eBooks · 2018

1. Biology and history of larger benthic foraminiferaHistory and biological classification of foraminiferaEcology of the living larger foraminiferaPalaeontological and evolutionary history of the larger foraminiferaTaxanomic features used in larger foraminiferal classificationBiostratigraphic distribution over time of larger foaminiferaGeneral factors effecting the evolution of marine species in the mid to late Phanerozic2. The Palaeozoic larger benthic foraminifera: The Carboniferous and PermianMorphology and taxonomy of Palaeozoic larger benthic foraminiferaBiostratigraphy and phylogenetic evolutionPalaeoecology of the fusulinidsPalaeogeographic distribution of the fusulinids3. The Mesozoic larger benthic foraminifera: the TriassicMorphology and taxonomy of Triassic larger benthic foraminiferaBiostratigraphy and phylogenetic evolutionPalaeoecology of Triassic foraminiferaPalaeogeographic distribution of Triassic foraminifera4. The Mesozoic larger benthic foraminifera: the JurassicMorphology and taxonomy of Jurassic larger benthic foraminiferaBiostratigraphy and phylogenetic evolutionPalaeoecology of Jurassic foraminiferaPalaeogeographic distribution of Jurassic foraminifera5. The Mesozoic larger benthic foraminifera: the CretaceousMorphology and taxonomy of Cretaceous larger benthic foraminiferaBiostratigraphy and phylogenetic evolutionPalaeoecology of Cretaceous foraminiferaPalaeogeographic distribution of Cretaceous foraminifera6. The Palaeogene larger benthic foraminiferaMorphology and taxonomy of Palaeogene larger benthic foraminiferaBiostratigraphy and phylogenetic evolutionPalaeoecology of Palaeogene foraminiferaPalaeogeographic distribution of Palaeogene foraminifera7. The Neogene larger benthic foraminiferaMorphology and taxonomy Neogene larger benthic foraminiferaBiostratigraphy and phylogenetic evolutionPalaeoecology of Neogene foraminiferaPalaeogeographic distribution of Neogene foraminifera8. SynthesisImportance of application of larger foraminifera in biostratigraphyImportance of larger foraminifera as marine environmental indicatorsThe significance of the larger foraminifera assemblages in the understanding of the global distribution of carbonate sediments and their value in contributing raw data to palaeoenvironmental and palaeoclimatic modelsAppendixNomenclature terminology and glossary

W. Prasidha, M. Taufiq

· 2021

This study was aimed at evaluating the effect of sodium acetate on the performance of aerated double chamber microbial fuel cells from tofu whey. Six different mass of sodium acetate was soluted in the anode chamber (0, 1, 2, 3, 4, and 5 gr). The value of open circuit voltage (OCV) was taken to analyze the performance. A double chamber microbial fuel cell (MFC) was developed to produce electricity from tofu whey and studied for 1680 hours (70 days). Anode and cathode were made by uncoated graphite rod. After 1680 hours, the electricity production characteristics were obtained. The results show that the highest OCV (274 mV) was reached by adding 5 gr of sodium acetate in the anode chamber. Furthermore, adding 5 gr sodium acetate in the anode chamber could provide more stable OCV then other (0, 1, 2, 3, and 4 gr sodium acetate). From the study can be concluded that adding the sodium acetate in the anode chamber can provide stable and higher OCV.

Z. H. E N H E, ‡ N O R B E R T W A G N E R, T. A N G E N E N T

· 0

Z H E N H E , ‡ N O R B E R T W A G N E R , § S H E L L E Y D . M I N T E E R , | A N D L A R G U S T . A N G E N E N T * , ‡ Department of Chemical Engineering and Environmental Engineering Science Program, Washington University in St. Louis, St. Louis, Missouri 63130, Institute for Technical Thermodynamics, German Aerospace Center, D-70569 Stuttgart, Germany, and Department of Chemistry, Saint Louis University, St. Louis, Missouri 63103

Palash Pan, Nandan Bhattacharyya

Biofuels · 2024

Abstract Microbial fuel cells (MFCs) are indeed a promising technology with the potential to address energy shortages and environmental pollution simultaneously. MFC utilizes the metabolic activities of microbes to convert organic substrates into electrical energy. This study assesses the power production capabilities of an isolated bacterial strain from soil, Bacillus paramycoides NBPP1, using different configurations of MFCs. The organic waste from chicken butchery shop is used as nutrient and aluminum and graphite as anode and cathode respectively. The MFC achieved voltage in an open circuitof 662 mV, maximal density of power of 4 Wm−2, internal resistance of 898 Ω, and coulombic efficiency of 6.66% for dual chambers. For single chambers, the values were 649 mV, 570 Ω, 2.6 Wm−2, and 3.75% respectively. The COD removal efficiency was 57.14% for dual chambers and 47.16% for single chambers. The MFC also demonstrated LED illumination in a series circuit for a longer duration, with a maximum power density of 6.40 Wm−2. Additionally, the residual broth was found to be an effective organic fertilizer with adequate N, K, and sufficient P. This study highlights the sustainable resource utilization in MFC organic waste, which encompasses power generation, waste management, and the potential for organic fertilizer production.

M. Fernandez-Gatell, X. Sanchez‐Vila, J. Puigagut

· 2021

Bioelectrochemical systems (BES) are devices that transform the chemical energy of organic and inorganic substrates into an electric current. BES represents a particularly interesting biosensor technology for monitoring the performance of  remote/isolated wastewater treatment facilities (such as constructed wetlands). The work presented here aimed to assess the potential use of the electric signal produced by low-cost, membrane-less BES systems as an indicator of the operational conditions and treatment performance of natural-based wastewater treatment systems. For this purpose, several BES configurations and operation modes working under real domestic wastewater conditions were monitored. Results showed that the electric current produced by the BES significantly correlates with key parameters in biological-based wastewater treatment systems such as microbial activity and biomass, water COD or solids accumulation. Therefore, our work demonstrates the feasibility of applying bioelectrochemical-based low-cost biosensors for the improvement and control of natural-based wastewater treatment systems.     Keywords: bioelectrochemical systems, wastewater, microbial activity, organic matter, low-cost, biosensor

Dandan Liu

· 2018

Methane-producing Bioelectrochemical systems (BESs) is a promising technology converting renewable electricity into the form of storable methane. The objective of this thesis is to achieve efficient methane production in methane-producing BESs and investigate its applicability in full-scale powerto- gas projects. We focus on improving the biocathode performance by exploring suitable cathode materials and operational conditions, e.g. decreasing biocathode start-up time by using heat-treated stainless steel felt (Chapter 2), achieving high-rate methane production by using a granular activated carbon (Chapter 3). We also investigated the effect of intermittent electricity supply on performance of carbon-based biocathodes in methane-producing BESs (Chapter 4). We showed that integrating methane-producing BES into anaerobic digestion could be an attractive strategy to enhance the performance of anaerobic digestion in cold area (Chapter 5). Based on the results of this thesis, we evaluated the possible main issues by performing a techno-economic analysis of a full-scale methane-producing BESs (Chapter 6).

A. Tremouli, T. Kamperidis, G. Lyberatos

Molecules · 2021

Four multiple air–cathode microbial fuel cells (MFCs) were developed under the scope of using extracts from fermentable household food waste (FORBI) for the production of bioelectricity. The operation of the MFCs was assessed in batch mode, considering each cell individually. Τhe chemical oxygen demand (COD) efficiency was relatively high in all cases (>85% for all batch cycles) while the electricity yield was 20 mJ/gCOD/L of extract solution. The four units were then electrically connected as a stack, both in series and in parallel, and were operated continuously. Approximately 62% COD consumption was obtained in continuous stack operation operated in series and 67% when operated in parallel. The electricity yield of the stack was 2.6 mJ/gCOD/L of extract solution when operated continuously in series and 0.7 mJ/gCOD/L when operated continuously in parallel.

Uma Thanganathan

International Journal of Membrane Science and Technology · 2018

Membrane electrode assemblies (MEAs) for a low temperature H2/O2 fuel cell were fabricated using glass composite membrane and Pt/C electrode were evaluated by various operating condition. The stability and durability of the cell and polarization characteristics of membrane electrode assembles (MEAs) were reported. Electrochemical performances on MEAs consist of PWA {(12-tungsto(VI) phosphoric acid, n-hydrate)}/P2O5(phosphoric acid)/SiO2 (TEOS, tetraethoxysilane) glass composite membrane electrolyte and Pt/C electrode have been demonstrated representing a major milestone towards developing a viable atmospheric low temperature H2/O2 fuel cell system. MEAs were showed good performances under various functions of the temperature and relative humidity. A maximum current density of 141 mA/cm2 was obtained at 35 °C with 30% relative humidity by using a PWA/P2O5/SiO2 (5/5/90 mol%) glass composite membrane and Pt/C (0.1 mg/cm2) electrode. Polarization curves were recorded and their results support the conclusions obtained from the electrochemical impedance spectroscopy (EIS).

Monalisa Ghosh, G Mohan Rao

ECS Meeting Abstracts · 2018

Vertically aligned and tree-like nanostructures of carbon are grown by using plasma enhanced chemical vapour deposition (PECVD) method using electron cyclotron resonance (ECR) plasma system. These nanostructures consist of a multiwalled carbon nanotube which is aligned perpendicular to the surface of the substrate with carbon films attached to it like “branches” of a tree giving the structure a tree like appearance. The thin film of these nanostructures is deposited in a ECR plasma system on a nickel seed layer with a microwave power of 500 W using acetylene and hydrogen gas in 2:1 ratios as the source gases, at a working pressure of 7x10 -4 mbar in presence of a negative substrate bias of 200 V 1 . As the material with its vertical alignment and tree-like morphology has a very high exposed surface area, this material was speculated to act as a high-performance electrode of electrochemical capacitors (EC) or supercapacitors. The unique three-dimensional morphology of the material gives a high surface area with less areal footprint of the material. The electrochemical performance of the material as electrode of EC has been studied by depositing the material of thickness 1 μm on circular stainless-steel substrates of diameter 12 mm (area 1.13 cm 2 ). 1 M Na 2 SO 4 solution in deionised water is used as the electrolyte for the EC with absorbed glass mat as the separator between the two nanostructured electrodes. The entire assembly is done inside Swagelok type cell for testing the electrochemical performance. The EC showed a specific capacity of 920 μF/cm 2 (9.2 mF/cc) at a scan rate 0.1 V/s which is higher than the reported values for vertically aligned carbon nanotube. 2–4 A rectangular cyclic voltammetry curve is observed even at a voltage of 1 V/s. The results indicate that this material is a promising candidate for electrode material of supercapacitor. References M. Ghosh and G. M. Rao, Carbon 133 , 239–248 (2018). B. Hsia, J. Marschewski, S. Wang, J Bin In, C. Carraro, D. Poulikakos, C. P. Grigoropoulos and R. Maboudian Nanotechnology , 25, 055401(9pp) (2014) T. Chen, H. Peng, M. Durstock, and L. Dai, Sci. Rep. , 4 , 1–7 (2014). C. L. Pint et al., Carbon N. Y. , 49 , 4890–4897 (2011) Figure 1

Hojin Choi, Hyeonseok Yoon

Nanomaterials · 2015

The advent of novel organic and inorganic nanomaterials in recent years, particularly nanostructured carbons, conducting polymers, and metal oxides, has enabled the fabrication of various energy devices with enhanced performance. In this paper, we review in detail different nanomaterials used in the fabrication of electrochemical capacitor electrodes and also give a brief overview of electric double-layer capacitors, pseudocapacitors, and hybrid capacitors. From a materials point of view, the latest trends in electrochemical capacitor research are also discussed through extensive analysis of the literature and by highlighting notable research examples (published mostly since 2013). Finally, a perspective on next-generation capacitor technology is also given, including the challenges that lie ahead.

Jianfeng LIU, Zhenhai Zhang

ECS Meeting Abstracts · 2017

Carbon dioxide is known as the main greenhouse gas, which is enormous produced during human activities. The electrochemical reduction of carbon dioxide not only reduce the amount of CO 2 , also produce CO 2 to CO, the intermediate for the production of some chemical and fuels. However, the electrochemical reduction process for CO 2 is inhibited due to the lack of a suitable catalyst with high energy efficiency and high conversion rate. [1] The catalysts with the precious metal catalysts, such as Ag, Au, and Zn, Ni received high energy efficiency during carbon monoxide production. Some researchers utilize these metal catalysts for CO 2 reduction process, and received the corresponding results. [2] However, the cost of the precious metal is another urgent issue. In my prior work, the nitrogen-doped graphene is applied as a non-metal catalyst for oxygen reduction reaction process in aidic and alkaline media, finally exhibit high current density and mass activity. [3,4] In this work, we also heat treated carbon with the goal of doping nitrogen into carbon, and apply this nitrogen-doped carbon as catalyst for CO 2 electrochemical reduction process. The nitrogen-doped carbon catalyst exhibit higher current density and higher overpotential than the corresponding carbon, that is to say, the doped nitrogen atoms play an important role for the reduction process. [1] C. E.Tornow, M. R. Thorson, S.Ma, A. A. Gewirth, P. J. Kenis, Journal of the American Chemical Society, 134(48), 19520, (2012). [2] A. Salehikhojin, H. R. M. Jhong, B. A. Rosen, W. Zhu, S. Ma, P. J. A. Kenis, J.phys.chem.c, 117(4), 1627, (2017). [3] J. Liu, D. Takeshi, D. Orejon, K. Sasaki, S. M. Lyth, Journal of The Electrochemical Society, 161(4), F544, (2014). [4] J Liu, K Sasaki, SM Lyth, ECS Transactions 58 (1), 1751 (2013)

Fábio Rodrigo Freitas, Elki Cristina Souza

DESAFIOS - Revista Interdisciplinar da Universidade Federal do Tocantins · 2024

Concerns over environmental protection have increased in recent years, leading to a search for new renewable energy sources for minimizing anthropological damage to both atmosphere and water bodies. Microbial Fuel Cells are inserted in such a context, since they can reduce the organic load of an effluent concomitantly with the production of bioelectricity. This study investigated three different sources of microorganisms, evaluating parameters such as carbon source concentration and temperature in energy efficiency. The electrical current generated by microbial activity in the oxidation of organic matter was monitored additionally with ionic conductivity and pH of the medium. Chemical Oxygen Demand was also determined towards an evaluation of the removal of organic matter. The Microbial Fuel Cell inoculated with Activated Sludge showed higher electrical current in comparison to other studies from the literature and a greater generation of electrical current and a high influence of conductivity on that efficiency was observed at 36 °C. As a conclusion, Microbial Fuel Cells can operate at both 4.0 gL-1 (COD mgO2 3,886.728) and 3.0 gL-1 (COD mgO2 3,124.573).

Na Chu, Yong Jiang, Donglin Wang et al.

Angewandte Chemie International Edition · 2023

Extensive study on renewable energy storage has been sparked by the growing worries regarding global warming. In this study, incorporating the latest advancements in microbial electrochemistry and electrochemical CO2 reduction, a super-fast charging biohybrid battery was introduced by using pure formic acid as an energy carrier. CO2 electrolyser with a slim-catholyte layer and a solid electrolyte layer was built, which made it possible to use affordable anion exchange membranes and electrocatalysts that are readily accessible. The biohybrid battery only required a 3-minute charging to accomplish an astounding 25-hour discharging phase. In the power-to-formate-to-bioelectricity process, bioconversion played a vital role in restricting both the overall Faradaic efficiency and Energy efficiency.The CO2 electrolyser was able to operate continuously for an impressive total duration of 164 hours under Gas Stand-By model, by storing N2 gas in the extraction chamber during stand-by periods. Additionally, the electric signal generated during the discharging phase was utilized for monitoring water biotoxicity. Functional genes related to formate metabolism were identified in the bioanode and electrochemically active bacteria were discovered. On the other hand, Paracoccus was predominantly found in the used air cathode. These results advance our current knowledge of exploiting biohybrid technology.

Ida Munfarida, Shinfi Wazna Auvaria

International Journal of Environmental, Sustainability, and Social Science · 2024

The increasing global demand for renewable energy and sustainable waste management solutions has inspired interest in microbial fuel cells (MFCs) as a dual-purpose technology for bioelectricity generation and waste treatment. This study explores the role of EM4, a consortium of effective microorganisms, in enhancing the voltage output and electrical conductivity of solid waste-powered MFCs. A batch system bioreactor assessed the impact of varying organic waste-to-zeolite ratios on MFC performance. The results demonstrated that a 1:1 ratio of organic waste to zeolite produced the highest electrical conductivity (3160 µS/cm) and the most substantial voltage output (777.5 mV) by day three of the experiment. Statistical analysis, including ANOVA and Kruskal-Wallis tests, revealed significant differences in voltage output across treatments, with a positive correlation between electrical conductivity and voltage production. These findings highlight the potential of integrating EM4 and conductive materials like zeolite to optimize bioelectricity generation in MFCs, contributing to the advancement of sustainable energy technologies.

Y. Kim, Hyeonaug Hong, Jaehyoung Yun et al.

Advanced Materials · 2020

Harvesting solar energy in the form of electricity from the photosynthesis of plants, algal cells, and bacteria has been researched as the most environment‐friendly renewable energy technology in the last decade. The primary challenge has been the engineering of electrochemical interfacing with photosynthetic apparatuses, organelles, or whole cells. However, with the aid of low‐dimensional nanomaterials, there have been many advances, including enhanced photon absorption, increased generation of photosynthetic electrons (PEs), and more efficient transfer of PEs to electrodes. These advances have demonstrated the possibility for the technology to advance to a new level. In this article, the fundamentals of photosynthesis are introduced. How PE harvesting systems have improved concerning solar energy absorption, PE production, and PE collection by electrodes is discussed. The review focuses on how different kinds of nanomaterials are applied and function in interfacing with photosynthetic materials for enhanced PE harvesting. Finally, the review analyzes how the performance of PE harvesting and stand‐alone systems have evolved so far and its future prospects.

Naoko Yoshida, Yuko Goto, Yasushi Miyata

C · 2016

Graphene oxide (GO) has been shown to be reduced by several microorganisms. Recent studies of the growth of Geobacter species in the presence of GO and electricity production by recovery of electrons on the reduced form of GO (rGO) have indicated substantial benefits of GO and GO-respiring bacteria (GORB) in microbial electrochemical systems. In this study, we enriched GORB from a coastal sample to investigate the distribution and phylogenetic variety of GORB in seawater environments. X-ray photoelectron spectroscopy (XPS) and four-terminal probing revealed that the enriched microbial community (designated as CS culture) reduced GO and self-aggregated into a conductive hydrogel complex with rGO (the CS-rGO complex). In the process of GO reduction, certain bacterial populations grew in a manner that was dependent on GO respiration coupled with acetate oxidization. High-throughput sequencing of 16S rRNA as a biomarker revealed the predominance of Desulfomonas species at 92% of the total bacterial population in the CS culture. The CS-rGO complex produced electricity with acetate oxidization, exhibiting less than 1 Ω/cm3 of charge transfer resistance. Thus, these results suggested that Desulfomonas species could grow on rGO and produce electricity via the reduced form of GO.

Walaa Ibrahim Gabr

Alexandria Engineering Journal · 2015

Xuewen Liu, Panqing Qi, Wei Fan et al.

Advanced Science · 2025

Biological nitrogen fixation (BNF) is a pivotal process that reduces nitrogen to ammonium within the nitrogen cycle. Extracellular electron transfer (EET) between diazotrophs and the extracellular environment influences the occurrence and efficiency of BNF. Although extracellular electron acceptors can function as a component of the electron transport chain, providing energy for chemotrophic nitrogen fixation via extracellular respiration, the function and mechanism of outward EET in photosynthetic diazotrophs remain unclear. Here, using Rhodopseudomonas palustris TIE-1, a photosynthetic bioelectrochemical nitrogen fixation system is established for simultaneous nitrogen fixation and current generation, to dissect the complex interaction between these two processes. Outward EET functions are found to maintain redox balance, rather than serving as an extracellular respiration pathway. It significantly suppresses BNF by competing with nitrogenase for electrons. Lumichrome serves as the primary electron shuttle for indirect electron transfer, while cytochromes play an important role in direct electron transfer. Notably, the pio operon participates in outward EET. This study reveals the interaction mechanism between photosynthetic BNF and outward EET, providing new insight into the regulatory mechanisms of nitrogen fixation in anoxygenic phototrophs across diverse environmental conditions.

Dexin Zhang, Siyuan Zhai, Ran Zeng et al.

Environmental Science and Ecotechnology · 2022

Traditional bioelectrochemical systems (BESs) coupled with stripping units for ammonia recovery suffer from an insufficient supply of electron acceptors due to the low solubility of oxygen. In this study, we proposed a novel strategy to efficiently transport the oxidizing equivalent provided at the stripping unit to the cathode by introducing a highly soluble electron mediator (EM) into the catholyte. To validate this strategy, we developed a new kind of iron complex system (tartrate-EDTA-Fe) as the EM. EDTA-Fe contributed to the redox property with a midpoint potential of -0.075 V (vs. standard hydrogen electrode, SHE) at pH 10, whereas tartrate acted as a stabilizer to avoid iron precipitation under alkaline conditions. At a ratio of the catholyte recirculation rate to the anolyte flow rate (R C-A ) of 12, the NH 4 + -N recovery rate in the system with 50 mM tartrate-EDTA-Fe complex reached 6.9 ± 0.2 g N m -2 d -1 , approximately 3.8 times higher than that in the non-EM control. With the help of the complex, our system showed an NH 4 + -N recovery performance comparable to that previously reported but with an extremely low R C-A (0.5 vs. 288). The strategy proposed here may guide the future of ammonia recovery BES scale-up because the introduction of an EM allows aeration to be performed only at the stripping unit instead of at every cathode, which is beneficial for the system design due to its simplicity and reliability.

Ruitao Li, Xiang-peng Ren, Xinxin Fan et al.

iScience · 2024

Recent advancements in microbial fuel cells (MFC) technology have significantly contributed to the development of bio-cathode denitrification as a promising method for eco-friendly wastewater treatment. This study utilized an efficient repeated replacement method to enrich a mixed bio-cathode denitrifying culture (MBD) within a bio-cathode MFC, achieving a stable maximum output voltage of 120 ± 5 mV and a NO 3 - -N removal efficiency of 69.99 ± 0.60%. The electrotrophic denitrification process appears to be facilitated by electron shuttles. Microbial community analysis revealed a predominance of Proteobacteria , with Paracoccus and Pseudomonas as functional genera. Additionally, the isolated strain Lyy (belonging to Stutzerimonas ) from MBD demonstrated exceptional denitrification efficiencies exceeding 98% when treating wastewater with a broad range of C/N (2-12) ratios and KNO 3 concentrations (500-3000 mg/L) within 60 h. These results demonstrated the effectiveness of the repeated replacement method in enriching bio-cathode denitrifiers and advancing MFC application in sustainable wastewater management.

Michael J. McAnulty, Venkata Giridhar Poosarla, Kyoung‐Yeol Kim et al.

Nature Communications · 2017

Given our vast methane reserves and the difficulty in transporting methane without substantial leaks, the conversion of methane directly into electricity would be beneficial. Microbial fuel cells harness electrical power from a wide variety of substrates through biological means; however, the greenhouse gas methane has not been used with much success previously as a substrate in microbial fuel cells to generate electrical current. Here we construct a synthetic consortium consisting of: (i) an engineered archaeal strain to produce methyl-coenzyme M reductase from unculturable anaerobic methanotrophs for capturing methane and secreting acetate; (ii) micro-organisms from methane-acclimated sludge (including Paracoccus denitrificans) to facilitate electron transfer by providing electron shuttles (confirmed by replacing the sludge with humic acids), and (iii) Geobacter sulfurreducens to produce electrons from acetate, to create a microbial fuel cell that converts methane directly into significant electrical current. Notably, this methane microbial fuel cell operates at high Coulombic efficiency.

So Ishizaki, Rimana Islam Papry, Hiroshi Miyake et al.

Frontiers in Microbiology · 2019

Integrated microbial fuel cell (MFC) and membrane bioreactor (MBR) systems are a promising cost-effective and energy-saving technology for wastewater treatment. Membrane fouling is still an important issue of such integrated systems in which aeration (oxygen) is replaced with anode electrodes (anodic respiration). Here, we investigated the effect of culture conditions on the membrane fouling potential of fouling-causing bacteria (FCB). In the present study, Klebsiella quasipneumoniae strain S05, which is an exoelectrogenic FCB isolated from a MBR treating municipal wastewater, was cultured with different external electron acceptors (oxygen, nitrate, and solid-state anode electrode). As results, the fouling potential of S05 was lowest when cultured with anode electrode and highest without any external electron acceptor ( p < 0.05, respectively). The composition of soluble microbial products (SMP) and extracellular polymeric substances (EPS) was also dependent on the type of electron acceptor. Protein and biopolymer contents in SMP were highly correlated with the fouling potential ( R 2 = 0.73 and 0.81, respectively). Both the fouling potential and yield of protein and biopolymer production were significantly mitigated by supplying electron acceptors sufficiently regardless of its types. Taken together, the aeration of MBR could be replaced with solid-state anode electrodes without enhancement of membrane fouling, and the anode electrodes must be placed sufficiently to prevent the dead spaces in the integrated reactor.

Dario Rangel Shaw, Muhammad Ali, Krishna P. Katuri et al.

Nature Communications · 2020

Anaerobic ammonium oxidation (anammox) bacteria contribute significantly to the global nitrogen cycle and play a major role in sustainable wastewater treatment. Anammox bacteria convert ammonium (NH 4 + ) to dinitrogen gas (N 2 ) using intracellular electron acceptors such as nitrite (NO 2 - ) or nitric oxide (NO). However, it is still unknown whether anammox bacteria have extracellular electron transfer (EET) capability with transfer of electrons to insoluble extracellular electron acceptors. Here we show that freshwater and marine anammox bacteria couple the oxidation of NH 4 + with transfer of electrons to insoluble extracellular electron acceptors such as graphene oxide or electrodes in microbial electrolysis cells. 15 N-labeling experiments revealed that NH 4 + was oxidized to N 2 via hydroxylamine (NH 2 OH) as intermediate, and comparative transcriptomics analysis revealed an alternative pathway for NH 4 + oxidation with electrode as electron acceptor. Complete NH 4 + oxidation to N 2 without accumulation of NO 2 - and NO 3 - was achieved in EET-dependent anammox. These findings are promising in the context of implementing EET-dependent anammox process for energy-efficient treatment of nitrogen.

Shanshan Chen, Xianyue Jing, Yongliang Yan et al.

Applied and Environmental Microbiology · 2020

Diazotrophs can produce bioavailable nitrogen from inert N 2 gas by bioelectrochemical nitrogen fixation ( e -BNF), which is emerging as an energy-saving and highly selective strategy for agriculture and industry. However, current e -BNF technology is impeded by requirements for NH 4 + assimilation inhibitors to facilitate intracellular ammonia secretion and precious metal catalysts to generate H 2 as the energy-carrying intermediate. Here, we initially demonstrate inhibitor- and catalystless extracellular NH 4 + production by the diazotroph Pseudomonas stutzeri A1501 using an electrode as the sole electron donor. Multiple lines of evidence revealed that P. stutzeri produced 2.32 ± 0.25 mg/liter extracellular NH 4 + at a poised potential of -0.3 V (versus standard hydrogen electrode [SHE]) without the addition of inhibitors or expensive catalysts. The electron uptake mechanism was attributed to the endogenous electron shuttle phenazine-1-carboxylic acid, which was excreted by P. stutzeri and mediated electron transfer from electrodes into cells to directly drive N 2 fixation. The faradaic efficiency was 20% ± 3%, which was 2 to 4 times that of previous e -BNF attempts using the H 2 -mediated pathway. This study reports a diazotroph capable of producing secretable NH 4 + via extracellular electron uptake, which has important implications for optimizing the performance of e -BNF systems and exploring the novel nitrogen-fixing mode of syntrophic microbial communities in the natural environment. IMPORTANCE Ammonia greatly affects global ecology, agriculture, and the food industry. Diazotrophs with an enhanced capacity of extracellular NH 4 + excretion have been proven to be more beneficial to the growth of microalgae and plants, whereas most previously reported diazotrophs produce intracellular organic nitrogen in the absence of chemical suppression and genetic manipulation. Here, we demonstrate that Pseudomonas stutzeri A1501 is capable of extracellular NH 4 + production without chemical suppression or genetic manipulation when the extracellular electrode is used as the sole electron donor. We also reveal the electron uptake pathway from the extracellular electron-donating partner to P. stutzeri A1501 via redox electron shuttle phenazines. Since both P. stutzeri A1501 and potential electron-donating partners (such as electroactive microbes and natural semiconductor minerals) are abundant in diverse soils and sediments, P. stutzeri A1501 has broader implications on the improvement of nitrogen fertilization in the natural environment.

Y. Liu, Mohan Qin, Shuai Luo et al.

Scientific Reports · 2016

We report an integrated experimental and simulation study of ammonia recovery using microbial electrolysis cells (MECs). The transport of various species during the batch-mode operation of an MEC was examined experimentally and the results were used to validate the mathematical model for such an operation. It was found that, while the generated electrical current through the system tends to acidify (or basify) the anolyte (or catholyte), their effects are buffered by a cascade of chemical groups such as the NH3/NH4+ group, leading to relatively stable pH values in both anolyte and catholyte. The transport of NH4+ ions accounts for ~90% of the total current, thus quantitatively confirming that the NH4+ ions serve as effective proton shuttles during MEC operations. Analysis further indicated that, because of the Donnan equilibrium at cation exchange membrane-anolyte/catholyte interfaces, the Na+ ion in the anolyte actually facilitates the transport of NH4+ ions during the early stage of a batch cycle and they compete with the NH4+ ions weakly at later time. These insights, along with a new and simple method for predicting the strength of ammonia diffusion from the catholyte toward the anolyte, will help effective design and operation of bioeletrochemical system-based ammonia recovery systems.

Umesh Ghimire, Veera Gnaneswar Gude

Scientific Reports · 2019

Abstract This study reports an investigation of the concept, application and performance of a novel bioelectrochemical nitritation-anammox microbial desalination cell (MDC) for resource-efficient wastewater treatment and desalination. Two configurations of anammox MDCs (anaerobic-anammox cathode MDC (AnA mox MDC) and nitration-anammox cathode MDC (NiA mox MDC)) were compared with an air cathode MDC (CMDC), operated in fed-batch mode. Results from this study showed that the maximum power density produced by NiA mox MDC (1,007 mW/m 3 ) was higher than that of AnA mox MDC (444 mW/m 3 ) and CMDC (952 mW/m 3 ). More than 92% of ammonium-nitrogen (NH 4 + -N) removal was achieved in NiA mox MDC, significantly higher than AnA mox MDC (84%) and CMDC (77%). The NiA mox MDC performed better than CMDC and AnA mox MDC in terms of power density, COD removal and salt removal in desalination chamber. In addition, cyclic voltammetry analysis of anammox cathode showed a redox peak centered at −140 mV Vs Ag/AgCl confirming the catalytic activity of anammox bacteria towards the electron transfer process. Further, net energy balance of the NiA mox MDC was the highest (NiA mox MDC-0.022 kWh/m 3 >CMDC-0.019 kWh/m 3 >AnA mox MDC-0.021 kWh/m 3 ) among the three configurations. This study demonstrated, for the first time, a N-E-W synergy for resource-efficient wastewater treatment using nitritation-anammox process.

Jiqiang Zhang, Zaiwang Zhang, Kun Rong et al.

Processes · 2022

In this study, a microbial fuel cell (MFC) that can achieve simultaneous anode anaerobic ammonium oxidation (anammox) and electricity generation (anode anammox MFC) by high-effective anammox bacteria fed with purely inorganic nitrogen media was constructed. As the influent concentrations of ammonium (NH4+-N) and nitrite (NO2−-N) gradually increased from 25 to 250 mg/L and 33–330 mg/L, the removal efficiencies of NH4+-N, NO2−-N and TN were over 90%, 90% and 80%, respectively, and the maximum volumetric nitrogen removal rate reached 3.01 ± 0.27 kgN/(m3·d). The maximum voltage and maximum power density were 225.48 ± 10.71 mV and 1308.23 ± 40.38 mW/m3, respectively. Substrate inhibition took place at high nitrogen concentrations (NH4+-N = 300 mg/L, NO2−-N = 396 mg/L). Electricity production performance significantly depended upon the nitrogen removal rate under different nitrogen concentrations. The reported low coulombic efficiency (CE, 4.09–5.99%) may be due to severe anodic polarization. The anode charge transfer resistance accounted for about 90% of the anode resistance. The anode process was the bottleneck for energy recovery and should be further optimized in anode anammox MFCs. The high nitrogen removal efficiency with certain electricity recovery potential in the MFCs suggested that anode anammox MFCs may be used in energy sustainable nitrogen-containing wastewater treatment.

Yutong Liu, Cong Chen, Xing Xue et al.

Water · 2025

The tobacco production process generates a substantial amount of wastewater characterized by high organics and low biodegradability, which poses a significant risk of severe environmental pollution. In order to explore a clean and low-cost technology for tobacco wastewater treatment, this study constructed two-chamber MFCs and investigated the performance of tobacco wastewater treatment and electricity generation capacity at room temperature. The incorporation of carbon sources (e.g., glucose, acetate, propionate, and butyrate) in wastewater could enhance the removal of COD, total nitrogen and ammonia nitrogen in wastewater. After three cycles, the maximum COD removal rate reached 75.97 ± 1.49%, while the maximum total nitrogen removal and ammonia nitrogen removal rates were 46.95 ± 1.77% and 48.31 ± 1.16%, respectively. Meanwhile, the maximum voltage output of 0.67 V was observed, and the maximum power density was 717.04 mW/m2. The microbial community analysis revealed that Trichococcus and Acinetobacter were present in high abundance in MFCs, which may play a significant role in electricity generation and wastewater treatment. These results demonstrate that MFC is applicable for tobacco wastewater treatment, providing both theoretical foundation and technical references for the large-scale practical application of MFC technology in tobacco wastewater treatment.

Haiman Wang, Zhuang Miao, Lei Chao et al.

Applied Sciences · 2020

Biocathode microbial electrochemical systems (MESs) that remove nitrogen compounds out of wastewater are of special interest for practice. High energy-input for aeration is one of the barriers that hinder their application on a wider scope. A trickling-bed biocathode MES (TB-MES) was developed by integrating biotrickling filters with a biocathode MES. By recirculating the catholyte and sprinkling it through a spray nozzle, the system was able to achieve a reoxygenation process, which could facilitate the creation of an aerobic and anoxic environment. At an optimal recirculation rate of 200 mL min−1, the TB-MES removed 87.2 ± 2.7% of ammonium nitrogen and 79.7 ± 2.5% of total nitrogen (TN), and simultaneously achieved a maximum power density of 3.8 ± 0.3 Wm−3. Comparable performances were achieved when treating domestic wastewater, which were 84.6 ± 2.4%, 70.1 ± 4.2%, and 3.2 ± 0.2 W m−3 for ammonium nitrogen removal, TN removal, and maximum power density. Pyrosequencing analysis revealed Nitrosomonas was more abundant in the upper portion of the carbon fiber brush biocathode (CFBup, 20.4%) and Azoarcus was more abundant in the lower portion (CFBbottom, 12.6%), which was probably caused by the difference in dissolved oxygen concentration in different parts of the biocathode. The TB-MES shows great promise for domestic wastewater treatment by employing biotrickling filters for oxygen supply in biocathode MES.

Yuh-Shan Ho

Water · 2020

Li et al. (2019) used inappropriate searching words and method to publish a bibliometric paper in Water. The results show a huge difference from the results by using an appropriate method. This comment points out each of problems.

Wei Tang, Xiao-Shuai Wu, Yan Qiao et al.

RSC Advances · 2018

Spherical mesopores with large pore width are more favorable to flavin mediated interfacial electron transfer in microbial fuel cells.

Yu-tong Shi, Yang-Yang Yu, Zi‐Ai Xu et al.

Journal of Materials Chemistry A · 2019

Superior carbon belts from Spirogyra were explored for highly efficient extracellular electron transfer and microbial energy harvesting.

N. Quach, T. Viet, P. V. Toan et al.

Indonesian Journal of Electrical Engineering and Computer Science · 2021

This paper presents a model of an intelligent energy harvesting system from microbial fuel cells (MFCs) in the wastewater treatment process. The model consists of two direct current (DC/DC) converters connected in a cascade. One DC/DC converter is used to capture energy from MFC and store it in a supercapacitor. The other DC/DC converter is responsible for increasing the low output voltage to a higher voltage level. In the paper, the MFC is modeled by a DC voltage source instead of a real MFC that contains wastewater inside it. The experimental results demonstrate that the model of an intelligent energy harvesting system can increase the low output voltage of MFC up to 3.3 V and achieve intermittent output power at a high level that can use in practice.

Yong Yuan, Ting Liu, Peng Fu et al.

Journal of Materials Chemistry A · 2015

Sewage sludge amended with biomass was converted into highly conductive biochar, which was used as a high-performance anode and cathode for microbial fuel cells.

Tole Sutikno, Tri Wahono, Hendril Satrian Purnama

Intellectual Journal of Energy Harvesting and Storage · 2023

Energy harvesting technology research has progressed significantly in recent years due to the increasing demand for alternative energy sources. One of the most promising methods of supplying renewable energy has been successfully put on the road, known as energy harvesting technology. There are four energy harvesting technologies on the roadway: solar, piezoelectric, thermoelectric, and geothermal. This paper discusses the development of energy harvesting technology on roadway other than geothermal, examines the basic principles of energy harvesting technology on the roadway, and provides an analysis and comparison of these technologies. Energy harvesting technology from energy conversion factors, weaknesses, and advantages that are most likely to be applied on the roadway is piezoelectric.

Alistair J. McCormick, Paolo Bombelli, Robert W. Bradley et al.

Energy &amp; Environmental Science · 2015

In this review we focus on a specific sub-branch of light-harvesting bioelectrochemical systems called biophotovoltaic systems.

Junki Saito, Kazuhito Hashimoto, Akihiro Okamoto

ECS Meeting Abstracts · 2016

Specific microbes are utilized for bioelectrode catalysis, at the anodic or cathodic electrode, in applications such as microbial fuel cells or electrosynthesis. In the anode chamber of microbial fuel cells (MFCs), microbial metabolism oxidizes organic compounds, and the electrons are transferred to the anode by extracellular electron transport (EET) processes. Despite numerous studies on the kinetics of EET to enhance the catalysis rate, the relevance with upstream reactions, including metabolism and intracellular electron transport chain, has scarcely been investigated. Herein, we investigate the rate-determining step for anodic current production ( j ) for the lactate oxidation of Shewanella oneidensis MR-1 by using riboflavin to specifically enhance the rate of EET via outer membrane c -type cytochromes (OM c -Cyts). 1 Microbial current production was measured in an anaerobic, three-electrode system poised at +0.4 V vs. SHE and kept at 303 K with 10 mM sodium lactate as a sole electron donor. Without the addition of flavin, j increases, saturates, and decreases as illustrated in Figure 1a. Upon the addition of 5µM riboflavin, j showed immediate increase in increasing and saturating current phases, though it increased sharper in the former (Figure 1b and c). In contrast, there was little effect of the riboflavin addition when j was decreasing (Figure 1d), suggesting that the RDS for j gradually shifted from EET to other upstream processes. Differential pulse (DP) voltammograms performed in each phases showed three peaks at approximately –230, –100, and +60 mV, which can be assigned to free riboflavin, bound riboflavin on OM c -Cyts, and the heme centers in OM c -Cyts, respectively. 2 Compared with the DP voltammogram when j was increasing, the peak current of the bound flavin showed a 50% decrease after j saturation, though the peak current of the heme centers was almost identical, indicating the dissociation of bound flavin from the OM c -Cyts. Given that flavin dissociation is induced by heme oxidation in OM c -Cyts, 2,3 the hemes in OM c -Cyts appear to become more oxidized after j saturation. These results further support the observation that the electron supply to OM c -Cyts from the upstream reactions gradually becomes slower than the EET rate. We will present the data for microbial growth, lactate consumption rate and voltammetric analysis in each phase, and the effect of trace metal removal from the medium to discuss the assignment of upstream reactions. Figure legend: Fig. 1. (a) A schematic image of the time course of current production. Area b, c, and d indicate the increasing, saturating, and decreasing current phase, respectively. (b–d) Current production in the presence (black lines) or absence (gray lines) of the addition of 5 µM riboflavin at the increasing (b), saturating (c), and decreasing (d) current phase, respectively. Arrows indicate the time points at which riboflavin was added. Microbes were added at t = 0 h. Reference 1. Dan C., Daniel B. B., Daniel R. B., and Jeffrey A. G.The Mtr Respiratory Pathway Is Essential for Reducing Flavins and Electrodes in Shewanella oneidensis . Journal of Bacteriology, 192, 2: 467–474 (2010). 2. Okamoto, A., Hashimoto, K., Nealson, K. H. and Nakamura, R. Rate enhancement of bacterial extracellular electron transport involves bound flavin semiquinones. P Natl Acad Sci USA 110, 7856-7861 (2013). 3. Okamoto, A. et al. Cell-secreted Flavins Bound to Membrane Cytochromes Dictate Electron Transfer Reactions to Surfaces with Diverse Charge and pH. Sci Rep-Uk 4, e5628 (2014) Figure 1