Razieh Rafieenia, Mohamed Mahmoud, Mahmoud S. Abdel‐Wahed et al.

Water • 2024

We developed a solar-driven photo-bioelectrochemical cell (s-PBEC) employing a novel anode photocatalyst material (Co3(PO4)2/Mg(OH)2) intimately coupled with electrochemically active bacteria for synergic electricity generation from wastewater. An s-PBEC was inoculated with a natural microbial community and fed with synthetic wastewater to analyze the performance of the system for electricity generation. Linear sweep voltammetry indicated an increase in power output upon light illumination of the s-PBEC after 1 h, rising from 66.0 to 91.5 mW/m2. The current density in the illuminated s-PBEC exhibited a rapid increase, reaching 0.32 A/m2 within 1 h, which was significantly higher than the current density in dark conditions (0.15 A/m2). Shotgun metagenomic analysis revealed a significant shift in the microbial community composition with a more diverse anodic biofilm upon illumination compared to the microbial communities in dark conditions. Three unclassified genera correlated with the enhanced current generation in illuminated s-PBEC, including Neisseriales (16.31%), Betaproteobacteria (7.37%), and Alphaproteobacteria (5.77%). This study opens avenues for further exploration and optimization of the solar-driven photo-bioelectrochemical cells, paving the way for integrative approaches for sustainable energy generation and wastewater treatment.

Yuan Yang, Zhen Fang, Yangyang Yu et al.

Water Science & Technology • 2019

A bioelectrochemical sensing system (BES) based on electroactive bacteria (EAB) has been used as a new and promising tool for water toxicity assessment. However, most EAB can reduce heavy metals, which usually results in low toxicity response. Herein, a starvation pre-incubation strategy was developed which successfully avoided the metal reduction during the toxicity sensing period. By integrating this starvation pre-incubation procedure with the amperometric BES, a sensitive, robust and mediator-free biosensing method for heavy metal toxicity assessment was developed. Under the optimized conditions, the IC50 (half maximal inhibitory concentration) values for Cu 2+ , Ni 2+ , Cd 2+ , and Cr 6+ obtained were 0.35, 3.49, 6.52, 2.48 mg L -1 , respectively. The measurement with real water samples also suggested this method was reliable for practical application. This work demonstrates that it is feasible to use EAB for heavy metal toxicity assessment and provides a new tool for water toxicity warning.

Zhimiao Zhao, Mengqi Cheng, Yanan Li et al.

Microbial Ecology • 2021

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.

Charles Amanze, Xiaoyan Wu, Richmond Anaman et al.

Journal of Hazardous Materials • 2024

Miaomiao Zheng, Jialu Xu, Xiaomei Xu et al.

International Journal of Electrochemical Science • 2025

Microbial electrosynthesis (MES) offers a sustainable bioelectrochemical platform for converting renewable electricity and carbon sources, particularly carbon dioxide, into value-added chemicals. Medium-chain fatty acids (MCFAs, C6–C12) are of growing industrial interest due to their versatile applications and potential for sustainable production independent of fossil resources. This review critically examines the biochemical pathways and electrochemical principles underlying MCFA synthesis in MES systems. It also evaluates key system components, including microbial catalysts (e.g., Clostridium, Eubacterium ), advanced electrode materials, and innovative reactor designs such as flow-through and fluidized bed configurations. Performance benchmarks, including production rates, titers, selectivity, and energy efficiencies, are summarized to assess technological progress. Major challenges related to electron transfer limitations, competing biological pathways, mass transfer constraints, and economic scalability are discussed. Finally, this review outlines future research directions and highlights how interdisciplinary advancements in reactor engineering, metabolic optimization, and system integration can accelerate the transition of MES from laboratory studies to industrial-scale sustainable bioproduction.

Ejike David Ugwuanyi, Zamathula Queen Sikhakhane Nwokediegwu, Michael Ayorinde Dada et al.

International Journal of Science and Research Archive • 2024

Anaerobic membrane bioreactors (AnMBRs) represent an innovative approach to wastewater treatment, combining anaerobic digestion with membrane filtration to achieve efficient organic pollutant removal and resource recovery. This review critically examines the potential of AnMBRs in wastewater treatment, highlighting their principles, advantages, challenges, recent advancements, and future prospects. AnMBRs offer several advantages over traditional aerobic treatment methods, including higher organic loading rates, reduced energy requirements, and biogas production through methane generation. However, challenges such as membrane fouling, reactor complexity, and operational costs have limited their widespread adoption. Recent advancements in membrane materials, fouling mitigation strategies, and process optimization have improved AnMBR performance and feasibility. Novel membrane materials with enhanced fouling resistance and durability have been developed, while innovative cleaning techniques and operational protocols have been implemented to mitigate membrane fouling and prolong membrane lifespan. Process optimization strategies, including reactor design modifications and operational parameter adjustments, have enhanced treatment efficiency and reduced energy consumption in AnMBRs. Future research directions in AnMBR technology focus on optimizing reactor configurations, exploring novel membrane materials and fouling control strategies, and conducting comprehensive techno-economic assessments to evaluate the environmental and economic sustainability of AnMBRs. Integration of AnMBRs with emerging technologies such as membrane distillation, forward osmosis, and bioelectrochemical systems holds promise for further enhancing treatment performance and resource recovery capabilities. Additionally, addressing knowledge gaps in membrane fouling mechanisms, microbial community dynamics, and long-term system stability is crucial for advancing AnMBR technology and facilitating its widespread implementation in wastewater treatment. Overall, AnMBRs offer significant potential for sustainable wastewater treatment, providing opportunities for organic pollutant removal, energy recovery, and resource reuse. By addressing technical challenges, optimizing process parameters, and conducting interdisciplinary research, AnMBRs can contribute to the development of efficient, cost-effective, and environmentally friendly wastewater treatment solutions, ultimately supporting the goal of achieving cleaner water resources and a more sustainable future.

Yue Dong, Yiying Jiang, Mingrui Sui et al.

Bioresource Technology • 2024

André Gemünde, Nils‐Lennart Ruppert, Dirk Holtmann

ChemElectroChem • 2024

Abstract Cupriavidus necator , despite lacking direct electron transfer capabilities, demonstrates efficient reduction of various redox mediators in oxygen‐free cultivation within bioelectrochemical systems. This study investigates the reduction site of ferricyanide through inhibition and expression rate analysis of oxygen and nitrate respiration chain complexes, comparing aerobic cultivation conditions with fructose as carbon and electron donor to autotrophic (CO 2 /H 2 /O 2 ) and anodic cultivation conditions (fructose/anode). Azide inhibition identified cytochrome c oxidase as the primary complex facilitating electron transfer to ferricyanide, with a secondary role proposed for nitrite reductase NirS, demonstrating a 3.9±1.1‐fold higher expression when exposed to anodic conditions. The 2.9±0.6‐fold increase in the expression of the natural porin OmpA under anodic conditions implies its potential involvement in ferricyanide uptake. Additionally, chemically permeabilizing cell membranes with cetyltrimethylammonium bromide doubles ferricyanide reduction rates without an anode present, offering insights for optimizing redox mediation in C. necator based bioelectrochemical systems. This study opens up new possibilities for the targeted optimization of mediated electron transfer in C. necator and other organisms.

Stefano Cestellos-Blanco, Hao Zhang, Ji Min Kim et al.

Nature Catalysis • 2020

Xiaochen Shi, Jianxun Xiao, Mayue Wang et al.

Chemical Engineering Journal • 2021

Dipak A. Jadhav, K. Gunaseelan, Giang T.H. Le et al.

Journal of environmental chemical engineering • 2024

Fatima Akram, Deborah Salamat, Taseer Fatima et al.

Journal of Electroanalytical Chemistry • 2025

Lijun Zhu, Huan Wang, Shaofeng Li et al.

Environmental Technology & Innovation • 2023

Soil bioelectrochemical system (SBES) has the potential to be applied to soil contaminated by total petroleum hydrocarbon (TPH), whereas the long-distance performance of vertical SBESs is not ideal due to the mass transfer limitation in soil matrix. In this study, a novel configuration of SBES was constructed with carbon fiber brushes as horizontal anodes, thus promoting TPH degradation and expanding the radius of influence (ROI) through a horizontal electronic pathway. The results showed that the removal rate of TPH was 46.4%–49.0% after 80 days in SBESs with carbon fiber brush, which was 113.8%–125.8% and 373.5%–400.0% higher than that of closed-circuit control and open-circuit control, respectively. The maximum ROI was over 135 cm in SBESs with carbon fiber brush, which was a 1.5 fold approximately increase than that of vertical SBES. In addition, the former cost was 1.97 $/g TPH, which was only one-fifth of the latter. These findings demonstrated that the horizontal carbon fiber brush amendment promoted the performance of TPH degradation far from SBES electrodes, which provided not only (i) a systematic approach focusing on ROI prediction in the application of SBES engineering, but also (ii) a novel configuration to improve TPH degradation in a green and economical way. • A Novel configuration of bioelectrochemical systems was constructed. • Long-distance horizontal electron pathway. was built by carbon fiber brush coupling. • An optimized electrode configuration through ROI prediction was provided.

Akil Ahmad

Biomass Conversion and Biorefinery • 2023

Jiaping Hu, Guangli Liu, Hui Li et al.

The Science of The Total Environment • 2022

Monireh Noori, Priyanka Gupta, Klaus Hellgardt et al.

Current Opinion in Environmental Science & Health • 2024

Accumulation of per- and polyfluoroalkyl substances (PFAS) in soil, sediment, and water poses significant public health risks due to their persistence and potential toxicity. PFAS compound possesses strong C – F bonds that require very high energy to break, making current technology unsustainable and challenging for large-scale treatment. Recent mechanistic insights into microbial degradation of PFAS offer promising solutions for their sustainable degradation. Specifically, bioelectrochemical systems can effectively break the strong C – F bonds in PFAS using high-energy electrons generated from electroactive microbes at a conductive anode electrode, achieving an astonishing removal efficiency of up to 96 %. However, these systems are still experimental, requiring further optimization for successful large-scale applications. This concise yet detailed review aims to enhance understanding of the emergence of PFAS as a pervasive potent chemical, microbe-assisted degradation mechanisms, and microbial community analysis, guiding future research and policy development for improved public health and environmental management. • With a C – F bond energy of 116 kCal/mol, PFAS are considered “forever chemical”. • Microbes using regenerable intracellular catalysts can efficiently degrade PFAS. • BES can enhance PFAS degradation using extracellular electrons from microbes. • Further metabolic improvement in microbes is required to enhance PFAS tolerance.

Hui Su Kim, Sangmin Lee, Sangmin Lee et al.

ChemSusChem • 2024

Microbial CO 2 electroreduction (mCO2ER) offers a promising approach for producing high-value multicarbon reductants from CO 2 by combining CO 2 fixing microorganisms with conducting materials (i. e., cathodes). However, the solubility and availability of CO 2 in an aqueous electrolyte pose significant limitations in this system. This study demonstrates the efficient production of long-chain multicarbon reductants, specifically carotenoids (~C 40 ), within a wet amine-based catholyte medium during mCO2ER. Optimizing the concentration of the biocompatible CO 2 absorbent, monoethanolamine (MEA), led to enhanced CO 2 fixation in the electroautotroph bacteria. Molecular biological analyses revealed that MEA in the catholyte medium redirected the carbon flux towards carotenoid biosynthesis during mCO2ER. The faradaic efficiency of mCO2ER with MEA for carotenoid production was 4.5-fold higher than that of the control condition. These results suggest the mass transport bottleneck in bioelectrochemical systems could be effectively addressed by MEA-assissted mCO2ER, enabling highly efficient production of valuable products from CO 2 .

Yunchuan Xian, Qiuhong Li, Yuan He et al.

Separation and Purification Technology • 2025

• ABR-MFC reactor efficiently treated low concentrations of 2,4-DTBP. • Power generation diminished as 2,4-DTBP concentration increased. • Proteobacteria and Nitrospirota decreased with increasing 2,4-DTBP. • 2,4-DTBP adversely impacted nitrogen metabolism of ABR-MFC reactor. 2,4-Di- tert -butylphenol (2,4-DTBP), a recalcitrant phenolic pollutant, poses a certain ecological risks due to its widespread industrial use. This study investigated the response of an anaerobic baffle reactor-microbial fuel cell (ABR-MFC) system to 2,4-DTBP in wastewater. Results showed that the ABR-MFC achieved > 99 % removal of 2,4-DTBP at low concentrations (1–2 mg/L). However, increasing 2,4-DTBP to 5 mg/L caused functional declines: ammonia–nitrogen removal reduced to 82.88 %, and power generation efficiency decreased (compartment1 resistance surged from 1282.2 Ω to 8068.4 Ω). Microbial analysis revealed that elevated 2,4-DTBP shifted community structure (increased Bacteroidota, decreased Proteobacteria/Nitrospirota) and enriched potential degraders ( Leptolinea and Syntrophorhabdus ). Functional predictions linked 2,4-DTBP stress to inhibited nitrogen cycling, with reduced abundance of nitrification ( amoA ) and denitrification genes ( nosZ , nirK/S ), suggesting incomplete denitrification. Path modeling further confirmed that 2,4-DTBP impaired nitrogen metabolism and bioelectrochemical stability despite enhancing microbial diversity. These findings provide critical insights for optimizing bioelectrochemical systems treating 2,4-DTBP contaminant.

Zihe Liu, Kai Wang, Yun Chen et al.

Nature Catalysis • 2020

Hina Younus, Masood Alam Khan, Arif Khan et al.

Catalysts • 2025

Laccases, a class of multicopper oxidases found in diverse biological sources, have emerged as key green biocatalysts with significant potential for eco-friendly pollutant degradation. Their ability to drive electron transfer reactions using oxygen, converting pollutants into less harmful products, positions laccases as promising tools for scalable and sustainable treatment of wastewater, soil, and air pollution. This review explores laccase from a translational perspective, tracing its journey from laboratory discovery to real-world applications. Emphasis is placed on recent advances in production optimization, immobilization strategies, and nanotechnology-enabled enhancements that have improved enzyme stability, reusability, and catalytic efficiency under complex field conditions. Applications are critically discussed for both traditional pollutants such as synthetic dyes, phenolics, and pesticides and emerging contaminants, including endocrine-disrupting chemicals, pharmaceuticals, personal care products, microplastic additives, and PFAS. Special attention is given to hybrid systems integrating laccase with advanced oxidation processes, bioelectrochemical systems, and renewable energy-driven reactors to achieve near-complete pollutant mineralization. Challenges such as cost–benefit limitations, limited substrate range without mediators, and regulatory hurdles are evaluated alongside solutions including protein engineering, mediator-free laccase variants, and continuous-flow bioreactors. By consolidating recent mechanistic insights, this study underscores the translational pathways of laccase, highlighting its potential as a cornerstone of next-generation, scalable, and eco-friendly remediation technologies aligned with circular bioeconomy and low-carbon initiatives.

Zhang Cheng, Avner Ronen, Heyang Yuan

ACS ES&T Water • 2023

Mechanistic models can provide predictive insight into the design and optimization of engineered biological systems, but the kinetic parameters in these models need to be frequently calibrated and uniquely identified. This limitation can be addressed by hybrid modeling that integrates mechanistic models with data-driven approaches. Herein, we developed a hybrid modeling strategy using bioelectrochemical systems as a platform system. The data-driven component consisted of artificial neural networks (ANNs) trained with mechanistically derived kinetic parameters as outputs to compute error signals. The hybrid model was built using 148 samples from the literature. After 10-fold cross-validation, the model was tested with another 28 samples. Internal resistance was accurately predicted with a relative root-mean-square error (RMSE) of 3.9%. Microbial kinetic parameters were predicted using the data-driven component and fed into the mechanistic component to simulate the system performance. The R2 values between predicted and observed organic removal and current for systems fed with a simple substrate were 0.90 and 0.94, respectively, significantly higher than those obtained from the stand-alone data-driven model (0.51 and 0) and mechanistic model (0.07 and 0.15). This strategy can potentially be applied to engineered biological systems for in silico system design and optimization.

Hongyue Sun, Shuai Luo, Ran Jin et al.

Journal of Power Sources • 2017

Subramaniapillai Niju, V. Shruthi, K. Priyadharshini

Sustainable Chemistry for the Environment • 2025

The food industrial sector holds a crucial position, as it satisfies the basic human need for sustenance while contributing to economic growth. Within this sector, the sago industry plays a vital role in the small-scale industrial sector and contributes to the local economy. However, the processing of tapioca roots requires a large quantity of water and simultaneously generates a large volume of the wastewater. The wastewater generated is highly organic in nature, which poses a serious threat to the environment if untreated. Conventional treatment methods are highly expensive and struggle to effectively manage the high pollutant load. So, there is a need for sustainable and cost-efficient treatment options. Biological treatment methods, particularly use of anaerobic processes, along with aerobic methods, are highly effective in reducing Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD) in sago wastewater because of its organic Content. However, these methods face enormous challenges, such as the need for the optimized operational conditions when dealing with varying wastewater compositions. In context to that the bioelectrochemical system, MFCs offers a sustainable approach by combining wastewater treatment along with bioelectricity generation. Use of this technique is highly advantageous, including improved COD removal and energy recovery. At the same time, they face some of the notable challenges, including scalability of the system performance. This review provides detailed knowledge on the characteristics nature of the sago wastewater and highlights the importance of biological treatment methods, pinpointing on aerobic and anaerobic treatments, as well as bio-electrochemical systems, emphasizing their role in COD removal and power generation. • Sago industry wastewater poses serious environmental threats due to high organic content. • Biological Treatment methods are cost - effective and effectively reduces the BOD and COD. • Bioelectrochemical system enable simultaneous wastewater treatment and bioelectricity generation. • Existing literature on biological treatment methods including bioelectrochemical systems for sago wastewater treatment were reviewed in detail.

Joanna Kazimierowicz, Marcin Dębowski, Marcin Zieliński

Energies • 2022

Recent years have brought significant evolution and changes in wastewater treatment systems. New solutions are sought to improve treatment efficiency, reduce investment/operational costs, and comply with the principles of circular economy and zero waste. Microbial granules can serve as an alternative to conventional technologies. Indeed, there has been fast-growing interest in methods harnessing aerobic (AGS) and anaerobic (AnGS) granular sludge as well as microbial-bacterial granules (MBGS), as evidenced by the number of studies on the subject and commercial installations developed. The present paper identifies the strengths and weaknesses of wastewater treatment systems based on granular sludge (GS) and their potential for energy production, with a particular focus on establishing the R&D activities required for further advance of these technologies. In particular, the impact of granules on bioenergy conversion, including bio-oil recovery efficiency and biomethane/biohydrogen yields, and bioelectrochemical systems must be assessed and optimized.

Shanshan Chen, Xintong Han, Shuyi Xie et al.

Electrochemistry Communications • 2023

Biological nitrogen fixation is a key step in the reduction of N2 to available nitrogen in the global nitrogen cycle. Pseudomonas stutzeri A1501 is an electroactive diazotroph and previous studies have shown that its nitrogen fixation performance is better in a micro-oxygen environment than in an oxygen-free environment. In this study, a bioelectrochemical system (nitrogen fixation in an anode chamber) was set up to explore whether extracellular electrodes can replace oxygen in acting as electron acceptors to drive ATP synthesis for nitrogen fixation by P. stutzeri under oxygen-free conditions. Nitrogenase activity, extracellular NH4+ production, increase of total nitrogen, 15N/14N atom ratio and the genes related to nitrogen fixation by P. stutzeri in the anodic bioelectrochemical group under oxygen-free conditions were at least 1.64 times higher than the corresponding values without electron output to the anode. The planktonic cells in the anode chamber were responsible for most of the electron output via an electron shuttle–electron transfer pathway. The transmembrane proton motive force produced by the transfer of electrons from the intracellular environment to the anode drives ATP synthesis to meet the high energy demand of the nitrogen fixation reaction in the absence of O2. These findings provide a basis for optimization of the nitrogen fixing performance of P. stutzeri in an oxygen-free environment.

Casper Borsje, Tom Sleutels, Wenying Zhang et al.

Journal of Power Sources • 2021

Capacitive bioanodes can be used to improve current production in bioelectrochemical systems for combination of energy recovery and wastewater treatment. Here, we compared current production in fixed and moving bed capacitive bioanodes. For fixed bed bioanodes, the recovered charge was studied as a function of the discharge current collector position and the thickness of the granule bed. The most capacitive charge was recovered from the current collector closest to the membrane. Increasing bed thickness from 5 mm to 10 mm resulted in a 1.6 times higher current density per membrane area. These findings were used to improve the design of a moving bed reactor, where granules moved through a discharge cell and were recirculated using a gas lift. The moving bed produced a current of 43 A/m2, about 2 times the fixed bed current over the full charging and discharging cycles. The relatively short discharge time and long charging time of the moving bed as compared to the fixed bed bioanodes led to higher capacitive currents. The design of the discharge cell and the ratio between charge and discharge times can be further optimized to make better use of stored charge of the granular capacitive bioanodes.

Waheed Miran, Wenyuan Huang, Xizi Long et al.

Patterns • 2022

Data science emerges as a promising approach for studying and optimizing complex multivariable phenomena, such as the interaction between microorganisms and electrodes. However, there have been limited reports on a bioelectrochemical system that can produce a reliable database until date. Herein, we developed a high-throughput platform with low deviation to apply two-dimensional (2D) Bayesian estimation for electrode potential and redox-active additive concentration to optimize microbial current production ( I c ). A 96-channel potentiostat represents <10% SD for maximum I c . 576 time- I c profiles were obtained in 120 different electrolyte and potentiostatic conditions with two model electrogenic bacteria, Shewanella and Geobacter . Acquisition functions showed the highest performance per concentration for riboflavin over a wide potential range in Shewanella . The underlying mechanism was validated by electrochemical analysis with mutant strains lacking outer-membrane redox enzymes. We anticipate that the combination of data science and high-throughput electrochemistry will greatly accelerate a breakthrough for bioelectrochemical technologies.

Sunghoon Son, Bonyoung Koo, Hyungwon Chai et al.

Journal of Water Process Engineering • 2025

Mohammed Hussien, Hend Omar Mohamed, Dipak A. Jadhav et al.

International Journal of Hydrogen Energy • 2025

Xintong Gao, Kaixuan Liu, Chong Zhang et al.

Bioresource Technology • 2024

Wan-Xin Yin, Shuang Luo, Xianbo Dong et al.

Chemical Engineering Journal • 2024

C. Joseph Kirubaharan, Jianwei Wang, Jianwei Wang et al.

Chemosphere • 2023

Federica Arena, Giorgio Giuffredi, A. Perego et al.

ChemElectroChem • 2021

Abstract The electrochemical reduction of CO 2 to value‐added products like formate represents a promising technology for the valorization of carbon dioxide. We propose a proof‐of‐concept bioelectrochemical system (BES) for the reduction of CO 2 to formate. For the first time, our device employs a nanostructured titanium nitride (TiN) support for the immobilization of a formate dehydrogenase (FDH) enzyme. The hierarchical TiN nanostructured support exhibits high surface area and wide pore size distribution, achieving high catalytic loading, and is characterized by higher conductivity than other oxide‐based supports employed for FDHs immobilization. We select the oxygen‐tolerant FDH from Thiobacillus sp. KNK65MA ( Ts FDH) as enzymatic catalyst, which selectively reduces CO 2 to formate. We identify an optimal TiN morphology for the enzyme immobilisation through enzymatic assay, reaching a catalyst loading of 59 μg cm −2 of specifically‐adsorbed Ts FDH and achieving a complete saturation of the anchoring sites available on the surface. We evaluate the electrochemical CO 2 reduction performance of the TiN/ Ts FDH system, achieving a remarkable HCOO − Faradaic efficiency up to 76 %, a maximum formate yield of 44.1 μmol mg −1 FDH h −1 and high stability. Our results show the technological feasibility of BES devices employing novel, nanostructured TiN‐based supports, representing an important step in the optimization of these devices.

Paola Andrea Palacios, Jo Philips, Anders Bentien et al.

Biotechnology Advances • 2024

Electromethanogenesis has emerged as a biological branch of Power-to-X technologies that implements methanogenic microorganisms, as an alternative to chemical Power-to-X, to convert electrical power from renewable sources, and CO 2 into methane. Unlike biomethanation processes where CO 2 is converted via exogenously added hydrogen, electromethanogenesis occurs in a bioelectrochemical set-up that combines electrodes and microorganisms. Thereby, mixed, or pure methanogenic cultures catalyze the reduction of CO 2 to methane via reducing equivalents supplied by a cathode. Recent advances in electromethanogenesis have been driven by interdisciplinary research at the intersection of microbiology, electrochemistry, and engineering. Integrating the knowledge acquired from these areas is essential to address the specific challenges presented by this relatively young biotechnology, which include electron transfer limitations, low energy and product efficiencies, and reactor design to enable upscaling. This review approaches electromethanogenesis from a multidisciplinary perspective, putting emphasis on the extracellular electron uptake mechanisms that methanogens use to obtain energy from cathodes, since understanding these mechanisms is key to optimize the electrochemical conditions for the development of these systems. This work summarizes the direct and indirect extracellular electron uptake mechanisms that have been elucidated to date in methanogens, along with the ones that remain unsolved. As the study of microbial corrosion, a similar bioelectrochemical process with Fe 0 as electron source, has contributed to elucidate different mechanisms on how methanogens use solid electron donors, insights from both fields, biocorrosion and electromethanogenesis, are combined. Based on the repertoire of mechanisms and their potential to convert CO 2 to methane, we conclude that for future applications, electromethanogenesis should focus on the indirect mechanism with H 2 as intermediary. By summarizing and linking the general aspects and challenges of this process, we hope that this review serves as a guide for researchers working on electromethanogenesis in different areas of expertise to overcome the current limitations and continue with the optimization of this promising interdisciplinary technology.

Shuai Luo, Xianzheng Zhu, Boya Fu et al.

Resources Conservation and Recycling • 2022

Gengxu Tian, Ziang Kong, Yifeng Zhang et al.

Bioresource Technology • 2024

Edina Klein, René Wurst, David Rehnlund et al.

Biofilm • 2024

Microbial electrochemical systems are a highly versatile platform technology with a particular focus on the interplay of chemical and electrical energy conversion and offer immense potential for a sustainable bioeconomy. The industrial realization of this potential requires a critical focus on biofilm optimization if performance is to be controlled over a long period of time. Moreover, the aspect and influence of cooperativity has to be addressed as many applied anodic bioelectrochemical systems will most likely be operated with a diversity of interacting microbial species. Hence, the aim of this study was to analyze how interspecies dependence and cooperativity of a model community influence the development of anodic biofilms. To investigate biofilm activity in a spatially resolved manner, a microfluidic bioelectrochemical flow cell was developed that can be equipped with user-defined electrode materials and operates under laminar flow conditions. With this infrastructure, the development of single and co-culture biofilms of the two model organisms Shewanella oneidensis and Geobacter sulfurreducens on graphite electrodes was monitored by optical coherence tomography analysis. The interdependence in the co-culture biofilm was achieved by feeding the community with lactate, which is converted by S. oneidensis into acetate, which in turn serves as substrate for G. sulfurreducens . The results show that co-cultivation resulted in the formation of denser biofilms than in single culture. Moreover, we hypothesize that S. oneidensis in return utilizes the conductive biofilm matrix build by G. sulfurreducens for direct interspecies electron transfer (DIET) to the anode. FISH analysis revealed that the biofilms consisted of approximately two-thirds G. sulfurreducens cells, which most likely formed a conductive 3D network throughout the biofilm matrix, in which evenly distributed tubular S. oneidensis colonies were embedded without direct contact to the anode surface. Live/dead staining shows that the outermost biofilm contained almost exclusively dead cells (98 %), layers near the anode contained 45-56 % and the entire biofilm contained 82 % live cells. Our results exemplify how the architecture of the exoelectrogenic biofilm dynamically adapts to the respective process conditions.

Lina Marcela Sanchez-Ledesma, Howard Ramírez-Malule, Jenny Alexandra Rodríguez-Victoria

Sustainability • 2023

This study presents a bibliometric analysis of the scientific literature on volatile fatty acids (VFA) production from wastewater fermentation published from 1981 to 21 June 2021. A total of 618 papers obtained from the Scopus database were analyzed using VOSviewer 1.6.16 software. According to the results, this topic has been capturing the attention of researchers over the years, but with different research approaches, including optimization of anaerobic digestion in two-stage reactors, biological removal of nutrients from wastewater, energy production in bioelectrochemical systems, and recovery of VFA as value-added intermediate products to be used as inputs in a variety of industries. In addition, the bibliometric networks obtained from the authors’ keyword frequency showed that wastewater treatment by using fermentation to obtain VFA as a value-added by-product is an emerging topic that undoubtedly requires further research and collaboration between scientific institutions. In this regard, different types of wastewater have been used as a substrate for acidogenic fermentation; however, and based on the results, the production of VFA from cassava processing wastewater is seen as one of the emerging issues of this field. Finally, evaluating the effect of operating conditions on the fermentation process, such as pH, hydraulic retention time, organic loading rate, temperature, inoculum and substrate concentration, independent of the final application of the VFA produced, is a relevant aspect for bioprocess optimization and implementation on a large scale.

Mingxia Liang, Guorong Luo, Ping Lei

International Journal of Electrochemical Science • 2025

The degradation of landscape ecosystems due to anthropogenic activities has led to the emergence of innovative ecological remediation strategies. Bioelectrochemical systems (BES), which integrate microbiology and electrochemistry, have demonstrated remarkable potential in addressing this challenge. BES technologies—including microbial fuel cells (MFCs) and microbial electrolysis cells (MECs)—simultaneously facilitate environmental remediation and resource recovery. This review explores recent advances in BES, focusing on the fundamental principles underlying microbial electron transfer, the role of advanced electrode materials, and the optimization of operational parameters to enhance system performance. Furthermore, the review highlights the successful application of BES in remediating polluted water bodies, soils, and sediments, while emphasizing their integration with landscape management practices to restore ecosystem functions. Innovations in reactor design and the incorporation of nanomaterials have enhanced the efficiency and scalability of BES for field applications. By fostering interdisciplinary collaboration across electrochemistry, microbial ecology, and materials science, this review advocates for the adoption of BES as a sustainable and multifunctional approach to ecological remediation. As BES technology progresses toward large-scale implementation, addressing technical challenges, optimizing system configurations, and refining regulatory frameworks will be essential for maximizing ecological benefits and promoting sustainable landscape management.