[object Object], [object Object], [object Object] et al.

Microbial Ecology • 2025

Biofilm formation is a survival strategy for bacteria, contributing to their persistence in natural and industrial environments. In this study, we investigated the ability of extracellular products (ECPs) produced by the probiotic strain Shewanella sp. Pdp11 under different culture conditions to inhibit biofilm formation in pathogenic and environmental Shewanella strains. ECPs from specific culture conditions altered biofilm formation in several Shewanella strains, with Shewanella hafniensis P14 displaying the highest sensitivity. Metabolomic analysis of the ECPs identified glycogen as a key metabolite associated with biofilm inhibition. Further genomic analysis of S. hafniensis P14 revealed an interruption in its glycogen synthesis pathway, suggesting a dependency on external glycogen-related metabolites for biofilm development. These findings demonstrate that Shewanella sp. Pdp11 ECPs can modify biofilm formation across multiple Shewanella strains, particularly in S. hafniensis P14 through glycogen-associated mechanisms.

[object Object], [object Object], [object Object] et al.

Fish and Shellfish Immunology • 2025

Recently, the infection with Shewanella spp. results in health disorders and mortalities in Nile tilapia (Oreochromis niloticus). The present trial is proposed to look into the impact of Shewanella spp. infection on the immune responses, antioxidant capacity, target genes expression of autophagy, endoplasmic reticulum stress (ER), and antimicrobial peptides in spleen tissue. As well as the antagonistic effects of chitosan nanogel composite (CNC; 75 μg/L) as a water application against Shewanella spp. infection were studied. One hundred and sixty fish (27.55±1.50 g) were assigned to four groups; each had four replicates for 14 days. The first (CONT) and second (CNC) groups were non-challenged and treated with 0 and 75 μg/L CNC, respectively, where the first was the control. The third (SH) and fourth (CNC+SH) groups were intraperitoneally challenged with 0.20 mL (containing 0.14 × 105 CFU) of Shewanella spp. The outcomes clarified that Shewanella spp. infection induced oxidative stress by lowering the activity of superoxide dismutase and reduced glutathione and increasing the malondialdehyde level. Increases in the serum levels of C-reactive protein, complement-3, and immunoglobulin M were noticed in the Shewanella-infected fish comparable to the CONT. Shewanella infection down-regulated the expression of Beclin-1 and microtubule-associated protein light chain kinase 3 in the spleen, while up-regulated the expression of the mechanistic target of rapamycin and ubiquitin-binding protein. In addition, up-regulation of the ER stress-related genes (CCAAT/enhancer-binding protein homologous protein, c-Jun N-terminal kinase, activating transcription factor 6, X box-binding protein-1, and binding protein for immunoglobulins) and antimicrobial peptides genes (Piscidin 4 and hepcidin antimicrobial peptide 1) were consequences of Shewanella Spp. infection compared to the CONT. On the contrary, CNC water treatment improved the survival of the Shewanella-infected fish (90%) compared to the CONT (77.50%). Moreover, an improvement in the antioxidant capacity and immune responses was noticed when the Shewanella-infected fish were treated with CNC. Modulation of the autophagy, ER stress, and antimicrobial peptide-related genes was noticed by treating the Shewanella-infected fish with CNC. Notably, CNC could be used as a water treatment for controlling the Shewanella challenge in Nile tilapia.

[object Object], [object Object], [object Object] et al.

Microorganisms • 2025

Extracellular electron transport (EET) supports the survival of specific microorganisms on the Earth’s surface by facilitating microbial respiration with diverse electron acceptors. A key aspect of EET is the organization of electron relays, i.e., multi-heme c-type cytochromes (MHCs), within the periplasmic space of microbial cells. In this study, we investigated the mobility of periplasmic electron relays in Shewanella oneidensis MR-1, a model strain capable of EET, using in vivo protein crosslinking to the MHCs. First, we established that crosslinking efficiency correlates with the spatial proximity and diffusion coefficient of protein molecules through in vitro tests. Based on these findings, we identified distinct molecular behaviors of periplasmic MHCs, showing that the tetraheme flavocytochrome FccA, which also serves as a periplasmic fumarate reductase, forms protein complexes with limited motility, while the small tetraheme c-type cytochrome CctA remains discrete and mobile. Both MHCs contribute to EET for bioelectrochemical nitrate and nitrite reduction. These findings reveal dual mechanisms for organizing periplasmic electron relays in EET, advancing our understanding of microbial extracellular respiration.

[object Object], [object Object], [object Object] et al.

Environmental Science: Nano • 2025

Shewanella oneidensis (S. oneidensis) MR-1 is a metal-reducing bacterium that can bio-reduce the carcinogenic hexavalent chromium (Cr6+) to the less toxic trivalent Cr3+. Bio-reduction is assisted by the protective role of Mn-ferrite NPs to bacteria.

[object Object], [object Object], [object Object] et al.

FEMS Microbiology Letters • 2025

Abstract The extracellular electron transport chain of Shewanella oneidensis MR-1 has been well characterized in the context of current generation on an anode. However, work to understand electron uptake from the cathode is less mature and major questions remain regarding the pathway and purpose of electron uptake. To employ this organism as a biocatalyst for microbial electrosynthesis, we must have a clear picture of the path of electrons into the cell to mitigate off-target reactions and find opportunities for pathway improvement. In this work, we confirm that the outer membrane electron conduit MtrCAB is essential for electron uptake, while the inner membrane cytochrome CymA is important but can be partially compensated for by other proteins. Additionally, we show that endogenous flavins are important for electron uptake and their absence cannot be complemented by exogenous flavins. Finally, hydrogenases are not directly involved in electron transfer but may play a role in cell survival during stationary phase on the cathode. Overall, the inward electron transfer pathway largely overlaps with the outward electron transfer pathway although we find differences in the role of flavins, particularly exogenously added riboflavin.

[object Object], [object Object], [object Object] et al.

International Journal of Molecular Sciences • 2025

Egg yolk immunoglobulin Y (IgY) possesses advantages such as low cost, easy availability, simple preparation, high antigen specificity, absence of drug residues, and compliance with animal welfare standards, making it an environmentally friendly and safe alternative to antibiotics. This research utilizes IgY antibody technology to develop a multivalent passive immune vaccine for major pathogenic bacteria in aquaculture. In this study, IgY antibodies against live Shewanella xiamenensis (LSX-IgY) and inactivated S. xiamenensis (ISX-IgY) were prepared by immunizing laying hens, and passive immunization protection experiments were conducted in Carassius auratus infected with S. xiamenensis and Aeromonas hydrophila. The passive immunization protection rates of LSX-IgY and ISX-IgY against S. xiamenensis were 63.64% and 72.73%, respectively, and the passive cross-protection rates against A. hydrophila were 50% and 71.43%, respectively. Further, C. auratus sera could specifically bind to S. xiamenensis or A. hydrophila in vitro, and the phagocytic activity of leukocytes was increased. LSX-IgY and ISX-IgY could reduce the bacterial load in the C. auratus kidneys. Meanwhile, they could significantly reduce the levels of antioxidant factors in serum and inhibit the mRNA expression of inflammation-related factors in the kidneys and spleens. Additionally, histopathology and immunofluorescence analysis showed that both IgY preparations preserved tissue integrity and reduced the expression of apoptosis factor (p53) and DNA damage factor (γH2A.X) of visceral organs, respectively. In summary, LSX-IgY and ISX-IgY can combat various bacterial infections, with no significant difference between the two. Additionally, inactivated bacterial immunization is more aligned with animal welfare standards for laying hens. Therefore, ISX-IgY is expected to serve as a multivalent vaccine against major aquaculture pathogens.

[object Object], [object Object], [object Object] et al.

Microorganisms • 2025

Antibiotic resistance is increasing at an alarming rate worldwide, in large part due to their misuse and improper disposal. Antibiotics administered to treat human and animal diseases, including feed supplements for the treatment or prevention of disease in farm animals, have contributed greatly to the emergence of a multitude of antibiotic-resistant pathogens. Shewanella is one of many bacteria that have developed antibiotic resistance, and in some species, multiple-antibiotic resistance (MAR). Shewanella is a rod-shaped, Gram-negative, oxidase-positive, and H2S-producing bacterium that is naturally found in the marine environment. In humans, Shewanella spp. can cause skin and soft tissue infections, septicemia, cellulitis, osteomyelitis, and ear and wound infections. Some Shewanella have been shown to be resistant to a variety of antibiotics, including beta-lactams, aminoglycoside, quinolones, third- or fourth-generation cephalosporins, and carbapenems, due to the presence of genes such as the blaOXA-class D beta-lactamase-encoding gene, blaAmpC-class-C beta-lactamase-encoding gene, and the qnr gene. Bacteria can acquire and transmit these genes through different horizontal gene-transmission mechanisms such as transformation, transduction, and conjugation. The genes for antibiotic resistance are present on Shewanella chromosomes and plasmids. Apart from this, heavy metals such as arsenic, mercury, cadmium, and chromium can also increase antibiotic resistance in Shewanella due to co-selection processes such as co-resistance, cross resistance, and co-regulation mechanisms. Antibiotics and drugs enter Shewanella spp. through pores or gates in their cell wall and may be ejected from the bacteria by efflux pumps, which are the first line of bacterial defense against antibiotics. Multiple-drug resistant Shewanella can be particularly difficult to control. This review focuses on the phenotypic and genomic characteristics of Shewanella that are involved in the increase in antimicrobial resistance in this bacterium.

[object Object], [object Object], [object Object] et al.

RSC Sustainability • 2025

Graphene sponge enables both cathodic and anodic reactions in microbial fuel cells. This free-standing graphene sponge electrode demonstrates high coulombic efficiency and current density.

[object Object], [object Object], [object Object] et al.

ENERGY & ENVIRONMENTAL MATERIALS • 2026

The persistence of antibiotics such as tetracycline in aquatic systems poses severe environmental and health risks by potential antimicrobial resistance. To address this, a hybrid photo‐electro‐Fenton oxidation system based on MXene‐derived electrodes was developed for efficient tetracycline degradation. The integration of photo, electro, and Fenton processes synergistically enhances hydroxyl radical (•OH) generation and charge‐carrier separation, ensuring superior removal efficiency. The cathode was synthesized via a Schiff base formation method, which facilitates functionalization of Ti 3 C 2 T x MXene with ferrocene, as confirmed by X‐ray diffraction, X‐ray photoelectron spectroscopy, and UV–visible spectrometry. The Ti 3 C 2 –TiO 2 photoanode was fabricated by electrochemical oxidation of Ti 3 C 2 T x . The photocatalytic properties of anatase TiO 2 , when combined with Ti 3 C 2 T x , create a Schottky junction that significantly improves charge separation, thereby enhancing the photo‐electrocatalytic activity of the system. The hybrid photo‐electro‐Fenton (PEF) system demonstrates a substantial enhancement in tetracycline removal efficiency (∼90%) compared to unmodified Ti 3 C 2 T x ‐based electrodes (∼46%). Furthermore, the Ti 3 C 2 –TiO 2 Schottky photoanode showed enhanced removal efficiency over a commercial P25‐based photoanode for photocatalytic degradation. Through this hybrid PEF oxidation system, the removal efficiencies achieved above 90% in neutral and acidic pH, indicating significant efficacy for the advanced oxidation process. The transformation products formed during the PEF process were analyzed with liquid chromatography coupled with high‐resolution mass spectrometry, showing breakdown of tetracycline and decreasing ecotoxicity with increasing treatment time. Moreover, the MXene‐derived electrode system demonstrates stability and consistent degradation performance over numerous cycles, making it a promising material for environmental remediation applications.

[object Object], [object Object], [object Object] et al.

Applied Physics Letters • 2026

As the BaTiO3 dielectric layer of multi-layer ceramic capacitors becomes thinner, the problem of leakage current degradation arises. In this study, the relationship between the Sn content in Ni–Sn internal electrodes and reliability enhancement is clarified. In addition, based on high-resolution interfacial observations, changes in the work function of the Ni–Sn internal electrode are examined to investigate the mechanism of insulation degradation suppression. Determination of the work function is conducted using both analytical and computational approaches. From these results, the mechanism by which Sn addition to Ni internal electrodes suppresses insulation degradation is discussed.

[object Object], [object Object], [object Object] et al.

Nano-Micro Letters • 2026

Abstract In response to the demanding requirements of next-generation energy storage systems for high-energy density, high-power density, and ultra-long-cycle life, the academic community has continued to focus on coupled devices that combine battery-level energy and capacitor-level power characteristics. Zinc-ion capacitors (ZICs) have become the most promising strategic candidate system for energy storage technology due to their high-energy/power characteristics, excellent intrinsic safety, and significant cost advantages. In this review, the latest research progress of ZICs is reviewed from the perspective of system. Firstly, ZICs are divided into zinc metal anode//capacitive cathode ZICs (ZC-ZICs) and capacitive anode//battery-type cathode ZICs (CB-ZICs) according to the device configuration, and the energy storage mechanisms are analyzed in depth. At the same time, focusing on the two configurations of ZC-ZICs and CB-ZICs and their electrolyte systems, problem-oriented the key puzzles and corresponding solutions are sorted out one by one. Finally, based on the above discussion, this review proposes forward-looking suggestions for material modifications of ZICs, including pulse voltage activation, application of high-entropy materials, and the development of stable and multi-functional electrolytes, aiming to provide scientific guidance for the practical application of high-performance ZICs and promote the in-depth development of high-performance ZICs research.

[object Object], [object Object], [object Object] et al.

Nano-Micro Letters • 2026

Abstract Wearable and deformable electronics are becoming increasingly essential components of modern healthcare and daily life. To power such devices, flexible electrochemical energy storage (FEES) plays a critical role. The practical performance of FEES is dominated by charge and mass transfer at the electrode-electrolyte interface, similar to many rigid battery technologies. However, a unique challenge for FEES is the durability of this interface under deformation. Herein, we present the first comprehensive review of the interface physics, unveiling the crucial role of interface adhesion in the mechanical endurance of FEES. By bridging adhesion physics, material chemistry, and device mechanics, adhesion reinforcement strategies are comprehensively discussed and quantitatively compared, providing multi-scale mechanisms for optimizing FFES interface - from nanoscale bond engineering to microscale surface topology, mechanical interlocking, and macroscale device design. Further, inspired by the synergetic effect of adhesion mechanisms, we propose potential research directions for durable electrode-electrolyte interfaces under dynamic deformation. We also revisit the evaluation of flexibility and electrochemical performance, proposing an application-driven bending index for device assessment. These insights on electrode-electrolyte interface physics of FEES will facilitate the flourishing future of flexible devices.

[object Object], [object Object], [object Object] et al.

Advanced Energy Materials • 2026

ABSTRACT Solid oxide electrochemical cells (SOCs) employ mixed ionic–electronic conducting (MIEC) perovskite electrodes, where electrochemical performance is dictated by the oxygen surface exchange coefficient ( k ) and the concentration of oxygen vacancies (δ). Conventional methods evaluate k and δ separately and under conditions that do not reflect their coupled behavior during operation, offering only a partial picture of the underlying processes. Here we report an in situ methodology that simultaneously resolves k and δ under realistic SOC operating conditions, using a dense bulk electrode integrated with a solid electrolyte. An applied overpotential induces an abrupt drop in the oxygen chemical potential gradient, enabling direct analysis of defect chemistry and surface reaction kinetics. The extracted values are consistent with those obtained from established characterization methods, validating the accuracy of the approach. Beyond fundamental characterization, the platform captures dynamic evolutions in defect chemistry and reaction kinetics, providing mechanistic insights into electrode degradation.

[object Object], [object Object], [object Object] et al.

Research Square • 2026

Abstract The development of high‐performance supercapacitor electrodes relies on materials that combine high electrical conductivity, large accessible surface area, and stable redox behavior. In this study, rGO/MnO₂/ Zeolitic Imidazolate Framework-8 (ZIF-8) composite electrodes were fabricated on nickel foam through a sequential electrophoretic deposition (EPD) technique. Graphene oxide was synthesized via the Tour method, MnO₂ was obtained through a co-precipitation process followed by calcination, and ZIF-8 was subsequently deposited to construct a ternary hybrid structure. Raman spectroscopy confirmed the formation of β-MnO₂ and rGO, with an increased I D /I G ratio (1.81), indicating higher defect density favorable for electrochemical activity. FESEM–EDX analysis revealed a hierarchical architecture composed of rGO nanosheets supporting MnO₂ nanoparticles and ZIF-8 crystals with uniform elemental distribution, confirming successful composite integration. Electrochemical characterization in 0.5 M Na₂SO₄ demonstrated that rGO/MnO₂/ZIF-8 electrode delivered the highest performance compared to pristine MnO₂ (17.19 F g⁻¹) and ZIF-8 (11.83 F g⁻¹), exhibiting a specific capacitance of 42.90 F g⁻¹ at 10 mV s⁻¹ (CV) and 30.74 F g⁻¹ at 0.1 A g⁻¹ (GCD).The b-value analysis suggested a combined capacitive and diffusion-controlled mechanism, while EIS results indicated a markedly reduced charge-transfer resistance (Rct = 180.8 Ω), attributed to the conductive rGO network and the porous ZIF-8 framework. These synergistic effects enhanced electron transport, ion diffusion, and redox activity. Overall, the rGO/MnO₂/ZIF-8 composite demonstrates improved electrochemical performance and structural stability, highlighting its potential as a promising electrode material for next-generation supercapacitors.

[object Object], [object Object], [object Object] et al.

AIChE Journal • 2026

Abstract Understanding the interplay between intrinsic kinetics and transport remains a central challenge in electrocatalysis. Rotating disk electrodes (RDE) are widely used because their transport can be described analytically, but radial concentration gradients complicate analysis of multi‐electron processes. Rotating cylinder electrodes (RCE) provide an improved convective transport profile that better separates transport from kinetics. However, multiphysics simulations show that the use of a single flat counter electrode distorts the electric field in low‐conductivity electrolytes. We present a third‐generation gastight RCE cell (RCE‐3) with two flat counter electrodes symmetrically positioned around the cylinder. This configuration doubles the counter electrode area, increases achievable current density, and improves field symmetry while maintaining well‐defined hydrodynamics. Electrochemical CO 2 reduction experiments demonstrate that asymmetric electric fields bias apparent kinetics in non‐aqueous electrolytes, whereas symmetric counter electrode operation minimizes these distortions, enabling reliable extraction of intrinsic kinetic parameters. The RCE‐3 cell contributes to advancing the mechanistic understanding of non‐aqueous electrocatalytic systems.

[object Object], [object Object], [object Object] et al.

Journal of The Electrochemical Society • 2026

Abstract One major degradation mechanism in Ni-yttria-stabilized-zirconia (Ni/YSZ) fuel electrodes is the migration of Ni away from the fuel electrode-electrolyte interface. This degradation mechanism continues to pose a significant challenge in context of fuel electrode supported cell (FSCs). It significantly impacts both electrochemical performance and electrode lifetime. Ni migration is typically observed when operating at high current densities that lead to high overpotentials. In this work, two fuel electrode supported cells are compared, both with respect to initial electrochemical performance and lifetime. The two cells had similar initial overall resistance when operated in steam electrolysis at -0.75 A/cm 2 , inlet of H 2 O/H 2 :90/10 at 750 °C. Cell 1 initially had low resistance due to physical processes i.e. concentration polarization (R conc ) and high resistance due to electrochemical processes at the Ni/YSZ electrode (R Ni/YSZ ); while Cell 2 was designed to have high concentration polarization (R conc ) and low resistance due to electrochemical processes at the Ni/YSZ electrode. This work shows that it is R Ni/YSZ – not R conc or total resistance - that is the determining resistance contribution for fuel electrode degradation and Ni migration. Furthermore, post-test analysis show presence of impurities and a microstructure indicating a pre-cursor state for Ni migration.

[object Object], [object Object], [object Object] et al.

Small Methods • 2026

ABSTRACT Flexible and wearable triboelectric nanogenerators (TENGs) are considered promising candidates for mechanical energy harvesting and self‐powered sensing, yet simultaneously achieving high output performance together with environmental adaptability remains challenging. In this study, a hydrophobic nanofiber‐reinforced paper‐based TENG (HF‐PTENG) was developed by integrating (3‐aminopropyl)triethoxysilane (APTES)‐modified polyacrylonitrile/aramid nanofiber (PANA) membranes and a flexible conductive paper electrode (FCPE). The HF‐PTENG delivered an open‐circuit voltage of 384.3 V, a short‐circuit current of 15.1 µA, and a transferred charge of 149.5 nC, achieving a maximum instantaneous power destiny of 2.1 mW/cm 2 . Stable electrical output was maintained over 11 000 operation cycles, and efficient biomechanical energy harvesting was demonstrated from finger tapping, wrist bending, and knee motions to power capacitors, commercial LEDs, and sensors. A smart glove integrated with the HF‐PTENG was designed to achieve wireless control of a miniature car via WiFi communication. In addition, a 3×3 TENG sensor array was constructed to visualize planar pressure distribution. Separately, convolutional neural network (CNN) analysis enabled the recognition of six finger‐drawn patterns with an accuracy of 98.32%. This study offers a practical and scalable strategy for constructing high‐performance, flexible TENGs with board potential for applications in wearable electronics, human–machine interfaces, and intelligent motion sensing.

[object Object], [object Object], [object Object] et al.

Energies • 2026

This study presents the electrochemical characterization of a novel, binder-free, plasma-treated aluminum/carbon electrode (“Surge”) using lithium metal half-cells. The low operating potential near 0 V vs. Li/Li+ enables the investigation of the electrode’s charge storage mechanisms and stability limits. We compare its electrochemical behavior in coin cells (CR2032) against two reference configurations: (i) the Surge electrode with a thin copper backer (Surge + Cu-backer) and (ii) a commercial graphite electrode on an aluminum current collector (C-REF). The Surge electrode demonstrated ultra-high initial specific capacities of up to approximately 4500 mAh/g (cycle 1) with Coulombic efficiencies exceeding 85% after the formation cycle. The observed capacity significantly exceeds the theoretical value for Li-Al alloying (993 mAh/g), indicating that lithium plating within the porous carbon scaffold contributes substantially to the total charge storage. However, this high performance was limited to approximately 8 to 9 stable cycles. Post-cycling analysis via scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (SEM/EDX) revealed a dominant failure mechanism: partial dissolution and consumption of the Al current collector leading to material redistribution. Quantitative EDX analysis showed a decrease in Al content from 45 at.% to 12 at.% alongside an increase in oxygen content from 8 at.% to 38 at.%, suggesting extensive Al-oxide formation. Critically, in the absence of a backer, Al-containing material deposited onto the stainless-steel cell components. The Cu backer served to redirect these deposits, improving current collection and modestly extending the short-term durability to approximately 1800 mAh/g at cycle 14 (approximately 75% capacity retention). In contrast, the C-REF control cell reached only approximately 1000 mAh/g (cycle 4) before failing within 5 to 6 cycles, underscoring the inherent instability of bare Al at low potentials. This characterization study establishes the Surge architecture as a successful proof-of-concept for ultra-high capacity charge storage and identifies Al dissolution as the dominant degradation mechanism. Future optimization must focus on stabilizing the Al substrate through protective interphases, alloying, or electrolyte engineering.

[object Object], [object Object], [object Object] et al.

Advanced Healthcare Materials • 2026

ABSTRACT Conductive polymer coatings have been extensively explored as a means of improving the quality of neural signals recorded with chronically implanted electrodes. They offer enhanced biocompatibility along with reduced electrode impedance and are reported to improve signal‐to‐noise ratio and signal amplitude. The mechanisms by which poly(3,4ethylenedioxythiophene) (PEDOT) and its derivatives enhance the quality of neural signals recorded in vivo, however, remain unclear. Here, a computational model of PEDOT:PTS (polythiophenesulfonyl chloride) coated neural recording electrodes is used to understand how the different properties of conductive electrode coatings influence local field potentials recorded in vivo. Impedance, histology and electrophysiology data were obtained from coated and uncoated microelectrodes chronically implanted in the rat basal ganglia and incorporated in the model. Together the simulation and experimental results indicate that improvements in signal quality with PEDOT:PTS coated electrodes are driven by greater neural proximity to the electrode, facilitated by reduced peri‐electrode gliosis. Reductions in thermal noise with decreasing electrode impedance further contributed to a higher signal‐to‐noise ratio for PEDOT:PTS coated electrodes. Finally, the results demonstrate that, provided amplifier input impedance requirements are satisfied, the enhanced recording capability of polymer coated electrodes compared to uncoated electrodes is due primarily to improved biocompatibility rather than reduced electrode impedance.

[object Object], [object Object]

Advanced Engineering Materials • 2026

4‐aminophenol (AMP) and 4‐acetamidophenol (ACP) are significant compounds in the pharmaceutical, dye, and cosmetic industries and analytical fields, with the uncontrolled release caused serious of environmental and health risks. So, necessitating their sensitive and selective detection through voltammetric studies. To achieve this, Chromium Titanium Yttrium oxide nanocomposites (CrTiYONC) were synthesised via a simple combustion method using chromium(III) nitrate, titanium(III) nitrate, and yttrium(III) nitrate as precursors, with glycine serving as the fuel. The combustion process is carried out at 750°C, producing phase‐pure nanostructures. These nanocomposites are then employed to modify the electrode surface, where an arginine‐functionalized polymeric film was electrochemically deposited onto the carbon paste electrode through the cyclic voltammetric technique. The modified electrode displays an enhanced active surface area, better conductivity, and augmented transfer of electron–proton owing to the synergistic effect of CrTiYO NC structures and the polymeric film. The electrochemical studies, like electrochemical impedance spectroscopy, cyclic voltammetry, linear sweep voltammetry, and differential pulse voltammetry, disclose that the AM‐CrTiYO‐CPE follows a diffusion‐controlled electrochemical redox mechanism with optimised conditions of 0.1 M BS solution at pH 7.2 in 0.1 V s −1 scan rate. The developed AM‐CrTiYO‐CPE validates remarkable electrocatalytic activity toward the detection of AMP and ACP, achieving low detection limits in a wide linear range. The fabricated electrode further displays an excellent stability, selectivity, sensitivity, reproducibility, and repeatability, with kinetics and availability of the electroactive site. The selective nature of the AM‐CrTiYO‐CPE electrode toward the quantification of AMP and ACP highlights its significant potential for applications in pharmaceutical formulation analysis, enironmental monitoring, drug delivery systems, quality control, and clinical diagnostics.

[object Object], [object Object], [object Object] et al.

Journal of The Electrochemical Society • 2026

To suppress dendrite formation, MoC-Mo 2 C electrode was selected as the working electrode for extracting Cr from LiCl-KCl molten salt. The MoC-Mo 2 C electrode was prepared by anodization at 0.005 A cm −2 for 2 h in Li 2 CO 3 -K 2 CO 3 molten salt, which displayed a porous structure. Then, the electrochemical mechanism of Cr(III) on this electrode was studied by cyclic voltammetry, square wave voltammetry, and current reversal chronopotentiometry, confirming that reduction of Cr(III)/Cr(II) and Cr(II)/Cr(0) was reversible and diffusion-controlled. The diffusion coefficient of Cr(III) was determined to be on the order of 10 –5 cm 2 s −1 in the temperature range of 713–833 K, and the diffusion activation energy of Cr(III) was also estimated. Meanwhile, the electrode kinetics of Cr(II)/Cr(0) was measured by Tafel and LP techniques. The exchange current density( j 0 ) measured by the two methods were very close, and j 0 increased with increasing the temperature. Moreover, the nucleation mechanism of Cr measured by CA conformed to instantaneous nucleation on MoC-Mo 2 C electrode. Potentiostatic electrodeposition was performed on Mo and MoC-Mo 2 C electrodes, respectively. The obtained products characterized by scanning electron microscopy-energy-dispersive microscopy and X-ray diffraction indicated that the formed Cr exhibited a sparse dendritic morphology on Mo electrode, while a dense spherical morphology on MoC-Mo 2 C electrode.

[object Object], [object Object], [object Object] et al.

Research Square • 2026

Abstract This study constructed a composite system using Shewanella oneidensis MR-1 and iron oxide-loaded biochar (FeO/C) to investigate the simultaneous removal of Cr(VI) and chlorpyrifos (CPF). The system achieved removal efficiencies of 73.47% for Cr(VI) and 70.12% for CPF within 144 h, fitting a pseudo-first-order kinetic model (k Cr k CPF ). SEM confirmed FeO/C as an effective colonization substrate facilitating bacterial adaptation. Oxidative stress analysis revealed an initial surge in reactive oxygen species that activated antioxidant enzymes (e.g., SOD, CAT), culminating in glutathione depletion and elevated malondialdehyde by 144 h. Proteomic profiling indicated that the upregulation of thioredoxin (trxC) and iron storage proteins (bfr) was crucial for maintaining redox balance and electron transfer. Furthermore, enriched metabolic pathways supported the energy demands for detoxification, elucidating the adaptive molecular mechanisms of the MR-1@FeO/C system under composite pollution.

Environmental science and pollution research international • 2025

Hydrogen is a promising alternative to meet the world's energy demand in the future because of its energetic characteristics. Microbial electrolysis cell (MEC) produces hydrogen from organic matter using exoelectrogenic bacteria. Shewanella oneidensis stands out for having the capacity to produce hydrogen using different electron transfer mechanisms. The present research aims to evaluate the hydrogen production efficiency in a MEC inoculated with a pure culture of S. oneidensis in different operational conditions. Since the use of a catalyst accounts for most of the MEC cost, no catalyst was used for anode or cathode. Experiments were performed in semi-continuous and batch mode using different electrodes, voltages applied, and medium in aerobic and anaerobic conditions. The highest hydrogen production rate (HPR) was 0.107 m 3 of H 2 /m 3 day obtained in a semi-continuous experiment using graphite plates and stainless steel electrodes. In batch experiments, a HPR occurred at 0.7 V, with a value of 0.048 m 3 of H 2 /m 3 day versus 0.037 m 3 of H 2 /m 3 day with 0.9 V. HPR was higher with carbon felt electrode (0.056 m 3 of H 2 /m 3 day). However, current density dropped after 38 h, with carbon felt electrodes, and did not recover. Results of the present research showed that the MEC using a pure culture of S. oneidensis can be considered an alternative for hydrogen production without using a catalyst. Also, S. oneidensis produced hydrogen in both anaerobic and aerobic conditions with low methane production. Optimization can be proposed to improve hydrogen production based on the operational conditions tested in these experiments.

[object Object], [object Object], [object Object] et al.

Environmental science & technology • 2025

Early detection of pollutants in water discharge is an integral part of environmental monitoring. Electroactive biofilm (EAB)-enabled, microbial fuel cell (MFC)-based biosensors facilitate self-powered online pollutant detection. However, as EABs are highly dynamic, naturally formed EABs as sensing and transducing elements limit the performance of MFC-based biosensors. Here, we report a fast-response and sensitive MFC-based biosensor enabled by enhancing Shewanella oneidensis biofilms on the electrode using an optogenetic approach. We incorporated a near-infrared (NIR) light-responsive synthetic bis(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) module into S. oneidensis to promote biofilm formation on the anode under NIR light. The biosensors with enhanced EABs exhibited a rapid and sensitive response to Cr(VI), reducing the sensing time from approximately 30 min to just 3 min. This improved sensing performance was maintained over three sensing cycles, even with fluctuating Cr(VI) concentrations. Based on the analyses of the electrode biofilms and extracellular polymeric substance matrices, different Cr(VI) response mechanisms for the normal and enhanced EABs were proposed; enhanced EAB's massive dispersal by Cr(VI) was the cause of the improved response of the biosensors. Such improved response still held in the natural water matrix. This proof-of-concept study provides valuable insights into controlling electrode biofilm dynamics for the rapid and robust early detection of pollutants using MFC-based biosensors.

Archives of microbiology • 2025

Dissimilatory metal-reducing bacteria (DMRB) have been considered very important contributors in developing and operating microbial fuel cells that represent one promising technology for waste treatment and sustainable energy generation. In keeping with this spirit, this review paper will scrutinise the elementary mechanisms whereby the unique metabolic processes of DMRB enable their role in facilitating the extracellular transmission of electrons to the anode from organic substrates. Important species like Shewanella and Geobacter are referred to because of their contributions toward improving the stability and efficiency of MFCs. The paper also discusses the benefits of using DMRB, such as their potential in bioremediation and increased electron transfer efficiency. Difficulties examined include preserving microbial stability, competing with other species, and improving operating conditions. The recent developments in materials science, genetic engineering, and integration with other renewable technologies are discussed to demonstrate the potential for future breakthroughs. The last section of this paper discusses the wider implications of DMRB in developing MFC technology for energy and environmental applications.

Journal of bioscience and bioengineering • 2025

Shewanella oneidensis MR-1 possesses an extracellular electron transfer (EET) pathway that enables bidirectional electron exchange with electrodes, making it a promising host for electro-fermentation (EF). However, the intracellular redox reactions driven by MR-1 during electron uptake from the electrodes remain poorly characterized. This study investigated the metabolic fate of pyruvate, a key fermentation intermediate, during inward electron transfer from a low-potential cathode. To examine this, an MR-1 derivative lacking formate dehydrogenase (ΔFDH), which is unable to utilize formate as an electron donor for pyruvate reduction, was incubated under open-circuit (OC) conditions and closed-circuit (CC) conditions with an electrode poised at -0.36 V (vs. the standard hydrogen electrode). A comparative analysis of pyruvate-derived metabolites under these conditions revealed that ΔFDH produced significantly higher amounts of d-lactate under CC conditions, indicating cathode-derived electron utilization for pyruvate reduction to d-lactate. Further gene knockout experiments in the ΔFDH background showed that two d-lactate dehydrogenases (D-LDHs) in MR-1, Dld (a quinone-dependent inner membrane D-LDH) and LdhA (an NADH-dependent D-LDH), contributed almost equally to cathode-dependent d-lactate production. These results indicate that electron transfer from electrodes to pyruvate in MR-1 cells involves both inner membrane quinone-mediated and NADH-mediated redox reactions, highlighting the potential applicability of MR-1 in diverse EF processes.

Analytical chemistry • 2025

Bioelectrochemical sensors (BES) are promising to specifically detect nitrate or nitrite but never realize simultaneous detection in a single system. In this study, a novel biosensor using self-assembled hydrogel bioelectrodes with reduced graphene oxide (rGO) and genetically engineered electroactive Shewanella species was designed for the simultaneous detection of nitrate and nitrite. The highly conductive rGO rendered a drastically improved reverse electron transfer from the electrode to Shewanella , which achieved a sensitive and quantitative response to nitrite/nitrate. Meanwhile, the genetically engineered Shewanella enabled efficient differentiation of nitrate and nitrite detection in a single system (a sensitivity of 883.48 μA mM -1 cm -2 to nitrate with a limit of detection of 0.92 μM and a sensitivity of 888.48 μA mM -1 cm -2 to nitrite with a limit of detection of 0.72 μM). The whole-cell biohydrogel based BES also showed excellent anti-interference and long-term storability for plug-and-play application. Based on these properties, this work demonstrated the power of genetically engineered electroactive bacteria in rGO biohydrogel for dual-analyte detection and also provided a new strategy for developing high-performance whole-cell BES for practical environmental monitoring.

Bioelectrochemistry (Amsterdam, Netherlands) • 2025

The nanowires of the model electroactive bacterium Shewanella oneidensis have been the subject of numerous studies to elucidate their structure and function. These previous reports have elegantly utilised advanced microscopic techniques to investigate nanowires formed in response to oxygen limitation. However, the detailed structure of nanowires formed on electrodes during extracellular electron transfer has not been reported and it is imperative to determine whether they possess the same vesicular structure that has been reported in the absence of extracellular electron transfer. Using an acetone hexamethyldisilazane dehydration method to preserve soft biological materials, we employed the relatively uncomplicated technique of secondary electron field emission-scanning electron microscopy to visualise the vesicular nanowire structure while attached to an electrode from an operating bioelectrochemical system. Early-stage nanowires appear to consist of intact chains of outer-membrane vesicles forming connections with the electrode surface and with neighbouring cells. Relying on secondary electrons from the inherently conductive carbon felt electrode, sputter coating could be avoided and the delicate structure of the vesicles was preserved with increased detail. The findings inform the fundamental understanding of nanowires during electron transfer and the simple protocol will allow their examination on a variety of existing and emerging electrode materials.

ACS sensors • 2025

As a water-soluble vitamin, Vitamin B2 (VB2) is crucial for the health of living organisms. Therefore, developing sensitive and selective methods for detecting VB2 is essential for the quality control of food and pharmaceuticals as well as for clinical diagnosis. In this study, a cell-embedded living graphene hydrogel needle was prepared under ambient atmospheric conditions, where the electroactive bacteria Shewanella oneidensis MR-1 was used to induce the reduction of graphene oxide (GO) to graphene hydrogel under the confinement effect with a glass capillary tube. By using this living graphene hydrogel needle, an electrochemical biosensor for the detection of VB2 in microdroplet samples was developed. By taking advantage of a microscale graphene needle and electroactive S. oneidensis MR-1, this biosensor exhibited high sensitivity (LOD = 8.42 nM), excellent selectivity, and good anti-interference ability for amperometric detection of VB2 in a microdroplet (1 μL, the record-low sample volume). This work provided a reliable tool for trace detection of VB2 with minimized sample requirement, offering a sensitive and practical approach for food safety inspection and disease diagnosis with precious or limited samples.

Applied and environmental microbiology • 2025

The key limiting factors on energy conversion efficiency in semiconductor-microbe hybrid systems remain inadequately understood. This study investigates the impact of ultrafast electron transfer kinetics at Cd x Zn 1- x S/ Shewanella oneidensis MR-1 interfaces on the overall efficiency of hybrid systems. The reduction efficiency of direct blue 71 dye by Cd x Zn 1- x S/MR-1 is significantly enhanced under light, leveraging the synergy of extracellular photoelectron transfer in various Cd x Zn 1- x S nanoparticles and associated redox pathways in MR-1. Notably, CdS/MR-1 achieved a 98% reduction compared to 31% for ZnS/MR-1 after 1 hour, despite ZnS exhibiting a more favorable conduction band potential of -1.37 V vs normal hydrogen electrode (NHE). Time-resolved spectra and density functional theory calculations reveal that the efficiency advantages of CdS/MR-1 are attributed to its longer photoelectron lifetime (1.14 ± 0.12 ps vs 0.18 ± 0.03 ps for ZnS/MR-1) and higher electron mobility (119.71 cm²/V·s for CdS/MR-1 vs 62.47 cm²/V·s for ZnS/MR-1), providing MR-1 with superior kinetic advantages in utilizing photoelectron energy. Additionally, experiments with exogenous cytochrome c demonstrate its crucial role in modulating extracellular and intracellular electron transfer kinetics at the Cd x Zn 1- x S/MR-1 interface. Transcriptomic analysis reveals similar photoelectron transfer pathways in CdS/MR-1 and ZnS/MR-1, supporting that CdS/MR-1's superior efficiency stems from kinetic advantages at the interface, leading to greater bioavailable photoelectron accumulation. These findings underscore the importance of optimizing photoelectron transfer kinetics to enhance extracellular photoelectron utilization efficiency in semiconductor-microbe hybrid systems.IMPORTANCEThe synergy of light-sensitive semiconductor elements (e.g., natural minerals) and microbes in natural matrices enhances biological functions and opens a wide range of biotechnological possibilities. Given the extremely short lifetimes of photoelectrons and rapid transfer rates at semiconductor-microbe interface, understanding this ultrafast electron transfer process is essential for elucidating the mechanism of extracellular photoelectron utilization and optimizing system efficiency. Our study demonstrates that Shewanella oneidensis MR-1 can benefit from photoelectrons through ultrafast electron transfer pathways, similar to photosynthetic systems. For microbes to efficiently utilize these photoelectrons before charge recombination on an ultrafast timescale, a prolonged photoelectron lifetime is kinetically advantageous. Our findings indicate that the superior efficiency of the CdS/MR-1 hybrid system is driven by kinetic advantages rather than thermodynamic factors. This foundational study is crucial for optimizing the energetics of semiconductor-microbe hybrid systems and expands our understanding of microbial energy metabolism.

Bioelectrochemistry (Amsterdam, Netherlands) • 2025

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is a widely recognized conducting polymer, especially in the field of electromicrobiology. Nonetheless, its inherently moderately hydrophobic and smooth surface poses a challenge for bacterial adhesion and biofilm formation, thereby restricting the growth and charge transfer of electroactive bacteria. To overcome these limitations, PEDOT:PSS films were modified with selected salts (FeCl 3 , MgSO 4 , MnCl 2 , CaCl 2 , BaCl 2 ) to improve bacterial attachment, biofilm formation and electrochemical performance, including charge storage capacity and charge transfer efficiency. Among the formed coatings, PEDOT:PSS@Ca demonstrated the highest charge storage capacity of 5.1 ± 1.0 mC/cm 2 in the presence of S. oneidensis MR-1, representing a three orders of magnitude increase when compared with pristine PEDOT:PSS. The improvement in biofilm formation was significant, with PEDOT:PSS@Ca attaining 55.0 ± 1.3 % biofilm formation and 92.8 ± 3.1 % bacterial viability, representing a considerable increase compared to unmodified PEDOT:PSS (4.1 ± 1.2 % biofilm formation and 63.1 ± 7.2 % viability). Calcium modification notably enhanced electron transfer by decreasing the charge transfer resistance, thereby promoting more effective electron exchange at the electrode interface. The findings indicate that functionalization of PEDOT:PSS with metal salts, and particularly CaCl 2 , is an effective approach for enhancing microbial fuel cell performance.

Advanced science (Weinheim, Baden-Wurttemberg, Germany) • 2026

Advancements in bioengineering have unlocked new microbial electrochemical applications in energy, sensing, remediation, and synthesis. Key to realizing these technologies is the engineering of conduits in metabolically versatile microbes like Escherichia coli to enable efficient charge exchange with the electrode. Inspired by mechanisms found in natural exogelectrogens, previous studies have largely focused on introducing conduits based on the metal-reducing (Mtr) pathway in Shewanella oneidensis MR-1. This study explores the concomitant expression of flavin secretion pathways for mediated charge transfer to complement the direct charge transfer from the bioengineered Mtr pathway. The engineered strains show a 3-fold increase in the total secretion of flavin mononucleotide (FMN) and riboflavin compared to a state-of-the-art Mtr-expressing strain lacking flavin overexpression. The concomitant flavin secretion further contributes up to a ≈3.4- and ≈1.5-fold increase in current compared to unmodified cells and the previous Mtr-expressing cells, respectively, with the greatest currents achieved for the strain favoring riboflavin secretion over FMN secretion. The introduction of flavin biosynthesis genes to Mtr-expressing strains thus reveals a distinct, yet complementary, EET mechanism for robust and multi-modal microbial applications.

Bioresource technology • 2026

Algal cathode microbial fuel cells (MFCs) are a promising technology for simultaneous wastewater treatment and bioenergy recovery. However, the fundamental mechanisms of light-mediated 'light-electricity-nitrogen' coupling via photosynthetic metabolites remain unclear, hindering system optimization. This study introduces a novel, simplified model using a defined co-culture of electrogenic Shewanella putrefaciens CN32 and Nannochloropsis oceanica in a dual-chamber MFC to decipher these interactions. Results show that light intensity critically regulates system performance, with an optimal range of 2000-5000 Lux. Within 48 h, this system achieved 49 % total nitrogen removal, a peak current density of 21.05 mA/m 2 , and a minimal charge transfer resistance (4.424 Ω). Mechanistically, photosynthetic oxygen plays a dual role: By enhancing algal nitrogen assimilation and central carbon metabolism, it facilitates the cathodic oxygen reduction through the synergy of biofilm porosity and extracellular polymeric substance-mediated electron shuttling. Furthermore, transcriptomic analysis revealed the molecular basis of this synergy, showing that light exposure upregulates algal genes for nitrogen transport and photosynthetic apparatus maintenance. This work elucidates the light-electricity-nitrogen network, demonstrating how light-regulated metabolites optimize pollutant removal and energy recovery, thereby establishing a theoretical foundation for sustainable algal bioelectrochemical applications.

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ChemElectroChem • 2025

Lipophilic electron shuttles (ESs), such as phenazine and phenoxazine, can penetrate the outer membrane and enter the periplasmic space, mediating extracellular electron transfer reactions. This study investigates how lipophilic ESs (resazurin, a phenoxazine) regulate carbon metabolic pathways in bioelectrochemical systems using Shewanella oneidensis MR‐1 as a model organism. Through the analysis of acetate yield, CO2 production, coulombic efficiency, and other parameters, it is found that resazurin increases coulombic efficiency (26% vs 17% for anthraquinone‐2,6‐disulfonic acid [AQDS]) and reduces acetate yield (82% vs 90% for AQDS) while slightly increasing CO2 production (13.1% vs 11.8% for AQDS), indicating a shift in carbon metabolism. Transcriptome analysis reveals significant upregulation of genes involved in the NADH‐dependent metabolic pathway (e.g., nuoHIJKLMN) and ATP synthesis (atpABDEFGH) under resazurin conditions. Mutant strains lacking key genes in oxidative phosphorylation (Δatp) or substrate‐level phosphorylation (Δack pta) further confirm the regulatory role of lipophilic shuttles. The study proposes that lipophilic ESs penetrate the periplasm, altering the redox state of inner‐membrane quinones and activating the NADH‐dependent metabolic pathway via the Arc system. This mechanism enhances TCA cycle activity and overall lactate metabolic efficiency. The findings provide insights into microbial carbon metabolic regulation and offer strategies for optimizing bioelectrochemical systems for bioremediation.

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Frontiers in Chemistry • 2025

Extracellular electron transfer (EET) enables certain microorganisms to respire using soluble and insoluble extracellular electron acceptors by transporting electrons across the cell envelope. Among these, G. sulfurreducens serves as a model organism for understanding direct EET pathways, where multiheme c-type cytochromes mediate electron transport from intracellular redox carriers to extracellular acceptors such as Fe(III) oxides and electrodes. This review focuses on heme-dependent electron transfer in Geobacter sulfurreducens, detailing the roles of inner membrane cytochromes, periplasmic carriers, outer membrane conduits, and recently characterized extracellular nanowires formed by polymerized multiheme c-type cytochromes, including OmcS, OmcE, and OmcZ. We examine the state of understanding of their physiological function, their structural features, expression patterns, and essentiality under various respiratory conditions. These insights advance our understanding of microbial anaerobic respiration and have implications for biogeochemical cycling, bioenergy generation, and bioremediation. The molecular architecture, assembly mechanisms, and secretion pathways of multiheme c-type cytochrome nanowires remain active areas of investigation, offering promising directions for future research and biotechnological innovation in engineered microbial systems.

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Bioscience, Biotechnology, and Biochemistry • 2025

Abstract The metal-reducing bacterium Geobacter sulfurreducens PCA is capable of anaerobic respiration using elemental sulfur as an electron acceptor. Despite 3 decades since its isolation, the molecular mechanisms underlying sulfur respiration remain unclear. In this study, we conducted a transcriptome analysis of G. sulfurreducens PCA cultured with and without sublimed sulfur. In the presence of sulfur, 153 genes were significantly up-regulated, while 599 genes were down-regulated. Notably, genes encoding redox proteins involved in energy conservation, particularly multiheme c-type cytochromes, exhibited altered expression patterns. In addition, elemental sulfur induced the transcription of genes associated with sulfur, selenium, and nitrogen metabolism, as well as protein redox homeostasis, DNA repair, and even cell motility. These transcriptional responses may reflect metabolic adaptation to sulfur respiration, redox state alterations, and sulfur-induced stress. Our findings uncover a complex regulatory landscape governing sulfur respiration and provide critical insights into this long-standing biochemical enigma in G. sulfurreducens PCA.

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Frontiers in Microbiology • 2025

Anaerobic digestion is a key technology for converting organic waste into methane, offering significant potential for renewable energy production and waste management. While the addition of conductive materials has been shown to improve direct interspecies electron transfer (DIET), their application faces challenges like biofouling, environmental risks, and increased operational costs. This study investigated the effects of co-culturing dual Methanosarcina (Methanosarcina barkeri and Methanosarcina acetivorans) and Geobacter metallireducens (DM-G) to enhance DIET and methane production without the addition of exogenous conductive materials. The performance of the DM-G co-culture system was comparable to that of the conductive material-amended single Methanosarcina and G. metallireducens (SM-G) co-culture systems, achieving a maximum methane concentration of 19.5 mM, following the consumption of 15.2 mM ethanol in the 1:1:1 biomass ratio system. This corresponds to a 3.8-fold increase over the SM-G co-culture system with M. barkeri and G. metallireducens, and a 3.0-fold increase over that with M. acetivorans and G. metallireducens. Transcriptomic analysis showed that in the DM-G co-culture system, M. barkeri up-regulated key genes related to methane metabolism and acetate utilization, while the core methanogenic pathway of M. acetivorans was down-regulated, but it could still effectively utilize the electron transfer pathway, indicating metabolic complementarity. These findings propose a novel strategy for enhancing DIET-driven methanogenesis through synergistic microbial consortia, advancing scalable, low-cost bioenergy solutions for organic waste valorization.

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Biofuels, Bioproducts and Biorefining • 2025

Abstract Bioelectrochemical systems (BESs) are emerging as a pivotal technology in waste valorization, with expanding applications in wastewater treatment, resource recovery, and greenhouse gas mitigation. This systematic review explores the diverse applications of BESs and their benefits in renewable energy production, waste management, and environmental protection. Based on biorefinery concepts, BESs are classified into three categories: waste‐to‐power, waste‐to‐fuel, and waste‐to‐chemicals. Key challenges affecting scalability are discussed, including cell design parameters, redox mediators, and electrode architecture. Among BES types, microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) are currently the most developed in terms of deployment and research investment. However, enzymatic electrochemical systems remain underexplored. As global demand grows for sustainable waste management solutions, BESs offer a promising platform that integrates resource recovery with environmental sustainability. Realizing their full potential will require continued innovation and collaboration among researchers, industry stakeholders, and policymakers to facilitate the transition from laboratory‐scale studies to large‐scale, practical applications.

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Sustainability • 2025

The underutilization of fruit waste in agroindustry—particularly star fruit—leads to leachate generation, emissions, and disposal costs, highlighting the need for circular alternatives that treat organic fractions while producing energy. This study evaluated the bioelectrochemical conversion of carambola (Averrhoa carambola) residues in single-chamber microbial fuel cells (MFCs). Three 1000 mL reactors were constructed using carbon anodes and zinc cathodes, operated for 35 days with continuous voltage recording and daily monitoring of pH, conductivity, and ORP. Polarization curves were obtained, and FTIR and SEM analyses were conducted to characterize substrate transformation and anode colonization. The anodic biofilm was also profiled using metagenomics. Measurements were performed using calibrated electrodes and a data logger with one minute intervals. The systems exhibited rapid startup and reached peak performance on day 22, with a voltage of 1.352 V, current of 3.489 mA, conductivity of 177.90 mS/cm, ORP of 202.01 mV, and pH of 4.89. The V–I curve indicated an internal resistance of 16.51 Ω, and the maximum power density reached 0.517 mW/cm2. FTIR revealed a reduction in bands associated with carbohydrates and proteins, consistent with biodegradation, while SEM confirmed extensive biofilm formation and increased anode surface roughness. Metagenomic analysis showed dominance of Acetobacter (59.35%), with Bacteroides (12.93%) and lactobacilli contributing to fermentative and electrogenic synergies. Finally, the series connection of three MFCs generated 2.71 V, sufficient to power an LED, demonstrating the feasibility of low-power applications and the potential for system scalability.

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Journal of Chemical Technology & Biotechnology • 2025

Abstract The globe will continue to confront major issues with environmental sustainability and energy in the years to come. As a result, it is crucial to pursue sustainable development to protect the environment and make the most of renewable energy sources. One promising approach involves using natural microorganisms to generate energy from affordable substrates through Microbial Fuel Cells (MFCs). These bioelectrochemical systems work by harnessing the ability of microbes to break down organic materials. This process releases electrons that travel through an external circuit, producing power. This review explores the basic principles and concepts behind MFCs, while also considering the key factors affecting their performance. The review provides a detailed analysis of MFCs, focusing on the characteristics and functions of exoelectrogens and the optimal conditions necessary for their efficient operation. It also discusses the working principles and mechanisms of MFCs, including recent advancements in the field. The primary focus of the review is on the potential and practical applications of this sustainable energy technology. It details various real‐world uses, including biosensors, electronic devices, desalination, and environmental bioremediation. © 2025 Society of Chemical Industry (SCI).