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A tubular microbial fuel cell/electro-Fenton (MFC/EF) combined system was developed for field-scale applications. This tubular MFC/EF combined system treats groundwater containing sulfolane by driving the Fenton reaction at the cathode using bioelectricity that is generated at the anode. Proper aeration and an adequate supply of carbon were found to improve significantly the performance of a tubular MFC/EF combined system. The tubular MFC/EF combined system exhibited high voltage output (525 mV) and high power density (691 mW/m3). The generation of H 2 O 2 from the cathode at 1 L/min aeration was 20 times that at 0.1 L/min, and achieved 100% removal efficiency of sulfolane (50 mg/L). The bicinchoninic acid assay detected an increase in the amount of bacteria by a factor of 2.2 as a result of electrical stimulation following tubular MFC/EF operation. The biotoxicity of sulfolane after tubular MFC/EF treatment revealed that the light inhibition of Vibrio fischeri was only 4% at 1 L/min aeration, owing to the by-product (SO 4 2-). The results demonstrated that the tubular MFC/EF combined system was effective in removing sulfolane and reducing the toxicity of by-products in the purification of water. [Display omitted] [ABSTRACT FROM AUTHOR]

The development of MFC using electroactive industrial microorganisms has seen a surge of interest because of the co-generation for bioproduct and electricity production. Vibrio natriegens as a promising next-generation industrial microorganism chassis and its application for microbial fuel cells (MFC) was first studied. Mediated electron transfer was found in V. natriegens MFC (VMFC), but V. natriegens cannot secrete sufficient electron mediators to transfer electrons to the anode. All seven electron mediators supplemented are capable of improving the electronic transfer efficiency of VMFC. The media and carbon sources switching study reveals that VMFCs have excellent bioelectricity generation performance with feedstock flexibility and high salt-tolerance. Among them, 1% glycerol as the sole carbon source produced the highest power density of 111.9 ± 6.7 mW/cm2. The insight of the endogenous electronic mediators found that phenazine-1-carboxamide, phenazine-1-carboxylic acid, and 1-hydroxyphenazine are synthesized by V. natriegens via the shikimate pathway and the phenazine synthesis and modification pathways. This work provides the first proof for emerging industrial biotechnology chassis V. natriegens as a novel high salt-tolerant and feedstock flexibility electroactive microorganism for MFC, and giving insight into the endogenous electron mediator biosynthesis of VMFC, paving the way for the application of V. natriegens in MFC and even microbial electrofermentation (EF). [ABSTRACT FROM AUTHOR]

The search for renewable energy sources has led to the development of plant microbial fuel cells (PMFCs). In this study, Epipremnum aureum plant species was used to generate bioelectricity in a PMFC, demonstrating the synergistic effect of corn cob and carbon road on the power generation and plant growth in PMFC. The maximum voltage output of PMFC with the composite corn cob and carbon rod anode was 465 mV which was 367 mV potential higher than the PMFC with the carbon rod anode only. The maximum power density obtained was 6.75 mW/m2. The results suggest that the use of corn cob has improved the biocompatibility of PMFC. The design of PMFC devices has been developed to increase power output which will be the next step of this research. [ABSTRACT FROM AUTHOR]

This article evaluated bioelectricity's evolving competitiveness and systemic complementarity benefits, both in comparison with other renewable sources. To do so, the results of several energy auctions were analysed, and a modelling exercise was developed using an optimisation model based on stochastic dual dynamic programming. The results indicate that wind and solar energies became the least cost expansions, and sugarcane bioelectricity lost significance and competitiveness in this environment. At the same time, the study shows that wind power's potential to be complementary to hydropower generation is greater than bioenergy in Brazil. These findings have relevant policy implications regarding the power sector and whether bioelectricity from sugarcane should still be incentivised along with wind power sources. It is worthwhile to point out that although the Brazilian case is explored in the article, it can be used as an example by other countries, especially developing ones, that can take advantage of Brazilian expertise on biomass exploitation aiming at integration with the power sector. [ABSTRACT FROM AUTHOR]

In this study, we presented the results of experiments designed to harvest energy from a bioreactor where exoelectrogenic Shewanella oneidensis bacteria were inoculated in the electrolyte solution containing a carbon source. In the absence of metal electrodes, external electrical circuit, proton-exchange membrane (PEM) or any possible sources of electric potential in the reactor, we associate the electric potential gradients with the capability to transport electrons through the conductive nanowires. Shewanella oneidensis bacteria produce the nanowires in the environment with limited electron acceptors. The nanowires facilitate electron transfer from the oxidizing zone (lower part of the reactor) and the reducing zone (upper part of the reactor), generating electric potential difference. Transmission electron microscopy (TEM) imaging revealed nanowire formation in the electrolyte solution. After inoculation with the liquid medium amended with a carbon source, open-circuit voltages were produced in the range of 380–470 mV. A scaling-up approach was demonstrated by connecting two reactors in series, producing a maximum of 960 mV. [ABSTRACT FROM AUTHOR]

The increase in the population and its need to produce food has caused the level of contamination by organic waste to increase exponentially in recent years. Innovative methods have been proposed for the use of this waste and thus to mitigate its impact. One of these is to use it as fuel in microbial fuel cells to generate electricity. This research aims to generate bioelectricity using coriander waste in microbial fuel cells. The maximum voltage and current observed were 0.882 ± 0.154 V and 2.287 ± 0.072 mA on the seventh and tenth day, respectively, these values were obtained working at an optimum operating pH of 3.9 ± 0.16 and with an electrical conductivity of 160.42 ± 4.54 mS/cm. The internal resistance observed in the cells was 75.581 ± 5.892 Ω, with a power density of 304.325 ± 16.51 mW/cm2 at 5.06 A/cm2 current density. While the intensity of the final FTIR (Fourier transform infrared spectroscopy) spectrum peaks decreased compared to the initial one, likewise, with a percentage of identity, it was possible to attribute 98.97, 99.39, and 100% to the species Alcaligenes faecalis, Alcaligenes faecali, and Pseudomonas aeruginosa. Finally, the cells were connected in series, managing to turn on an LED light (red) with the 2.61 V generated. This research provides an innovative and environmentally friendly way that companies and farmers can use to reuse their waste. [ABSTRACT FROM AUTHOR]

In the present study, the effects of electrode surface area, proton exchange membrane area, and volume of the anodic chamber were investigated on the performance of five different dual chamber microbial fuel cells (MFC) using synthetic wastewater toward wastewater treatment coupled electricity generation. In the batch mode, the five different MFC's were operated with the anodic chamber volumes of 93–890 mL, 17.33–56.77 cm2 electrode surface area, obtained volumetric power densities of 137.72–58.13 mW/m3, and unit area power densities ranging from 27.04 to 11.94 mW/m2. Fed-batch studies were done with the MFC having 740 mL anodic chamber volume at different wastewater COD concentrations. The power density per unit area increased from 22.93 mW/m2 to 36.25 cm2 when the distance between electrodes was reduced from 10 to 6 cm. A maximum volumetric power density of 135.21 mW/m3 has been attained with a 6 cm electrode distance with the accomplished COD reduction of 93.21%. The presence of biofilm on the anode has been visualized through the SEM images. The higher COD concentration of wastewater and the fed-batch operation resulted in increased power output and wastewater treatment efficiency. [ABSTRACT FROM AUTHOR]

Bioelectricity plays an essential role in the structural and functional organization of biological organisms. In this first article of our three-part series, we summarize the importance of bioelectricity for the basic structural level of biological organization, i.e. from the subcellular level (charges, ion channels, molecules and cell organelles) to cells. [ABSTRACT FROM AUTHOR]

Simple Summary: Numerous electrotherapeutic methods are commonly used in complementary and alternative veterinary medicine, as well as in conventional veterinary medicine. In these methods, electrical currents are commonly used to affect nerves, muscles, bones, or other tissues. In a systematic literature review, we collected information from published articles on electrotherapies used in horses, dogs, and cats. After screening 5385 articles of potential interest, we identified 41 articles that contributed to answering the overriding question: What is the scientific evidence for electrotherapy in horses, dogs, and cats? For most of the therapies, the number of studies was low with small numbers of animals. Many of the studies were of insufficient scientific quality and the electrotherapy was applied in many different clinical conditions and therapeutic settings. This made it difficult to reach robust conclusions, except for one: no current electrotherapies have sufficiently strong scientific evidence to support clinical effects in the treatment of horses, dogs, or cats with conditions affecting muscles, joints, nerves, or bones. Based on limited promising results, we have listed some electrotherapies that could be evaluated in more detail in high-quality studies. Electrotherapy modalities are currently used in the treatment of animals, but the evidence base supporting their use has not yet been systematically reviewed. Cochrane guidelines, as adapted by the Swedish Agency for Health Technology Assessment and Assessment of Social Services, were followed for this systematic review. A literature search regarding all currently known electrotherapy modalities applied to horses, dogs, and cats was conducted for the years 1980–2020 using three databases: CABI, PubMed, and Web of Science Core Collection. Of the 5385 references found, 41 articles were included in the review: 13 papers on pulsed electromagnetic field therapy (PEMFT), 7 on neural electrical muscle stimulation (NEMS), 5 on transcutaneous electrical nerve stimulation (TENS), 4 on static magnets, 3 on interference, 2 each on percutaneous electrical neural stimulation (PENS), bioelectricity, and diathermy, and 1 each on micro-pulsed stimulation, capacitive coupled electrical stimulation, and microwave therapy. The literature per modality was limited in quantity (mean 3.7 papers). Half of the articles were assessed to have a high risk of bias (20 high, 7 moderate, and 14 low). The existing literature used a spectrum of indications and treatment parameters, which makes comparisons and drawing conclusions to support the use of these modalities in clinical practice challenging. The current scientific evidence is not sufficient to support the clinical effects of electrotherapies for any clinical indication in horses, dogs or cats. The selected suggestive results warrant further high-quality research on PEMFT, NEMS, TENS, and PENS. [ABSTRACT FROM AUTHOR]

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In this study, constructed wetland-microbial fuel cell (CW-MFC) filled with modified basalt fiber (MBF) via iron modification was utilized for treating perfluorooctanoic acid (PFOA) containing sewage. Results showed the significant promotion by bioelectricity on ammonium and total nitrogen by 7.80–8.14 %. Although such enhancement was suppressed by PFOA, higher removal was still observed with closed circuit, and PFOA removal also increased by 9.05 %. Bioelectricity contributed to enrichment of bacteria involved in nitrifying (Nitrospira and Ellin6067), denitrifying (like Thauera and Dechloromonas), iron redox (Geobacter), and sulfate-reducing (Desulfobacter) , aligned with up-regulated of functional genes, including amoA , narG , napA , narK , narS , nrfA , sulp and sqr. Enrichment of autohydrogenotrophic and sulfide-oxidizing autotrophic denitrifiers, and nitrate dependent iron oxidation bacteria by bioelectricity all promoted denitrification. Moreover, bioelectricity boosted relative abundance of organic compounds degradation enzymes, such as dehydrogenase, decarboxylase, and dehalogenase, supporting the enhancement on PFOA removal. Generally, PFOA was converted to short-chain perfluorocarboxylic acids (PFCAs) via decarboxylation, hydroxylation, HF elimination, hydrolysis, F- elimination, C-C bond scission, and dehydration in CW-MFC. The final PFCAs-products determined was perfluorobutyric acid. This work estimated feasibility of treating PFOA containing sewage by CM-MFC, and offered new insights on enhancing mechanisms of nitrogen and PFOA conversion. [Display omitted] • Bioelectricity promoted nitrogen and phosphorus removal by 5.71-8.14 %. • Perfluorooctanoic acid removal increased by 9.05 % with closed circuit. • Bioelectricity stimulated bacteria and genes involved in C, N, Fe, and S cycling. • Key enzymes like dehalogenase could promote perfluorooctanoic acid degradation. • Perfluorobutyric acid was the final short-chain product of perfluorooctanoic acid. [ABSTRACT FROM AUTHOR]

Oligodendrocyte precursor cells (OPCs) generate myelinating oligodendrocytes and are the main proliferative cells in the adult central nervous system. OPCs are a heterogeneous population, with proliferation and differentiation capacity varying with brain region and age. We demonstrate that during early postnatal maturation, cortical, but not callosal, OPCs begin to show altered passive bioelectrical properties, particularly increased inward potassium (K+) conductance, which correlates with G1 cell cycle stage and affects their proliferation potential. Neuronal activity-evoked transient K+ currents in OPCs with high inward K+ conductance potentially release OPCs from cell cycle arrest. Eventually, OPCs in all regions acquire high inward K+ conductance, the magnitude of which may underlie differences in OPC proliferation between regions, with cells being pushed into a dormant state as they acquire high inward K+ conductance and released from dormancy by synchronous neuronal activity. Age-related accumulation of OPCs with high inward K+ conductance might contribute to differentiation failure. [Display omitted] • OPCs acquire inward potassium conductance with age • Inward potassium conductance underlies OPC heterogeneity • Inward potassium conductance inversely correlates with OPC proliferation • Neuronal activity lowers inward potassium conductance and increases proliferation Pivoňková et al. show that oligodendrocyte precursor cells (OPCs) acquire inward potassium conductance at different times, causing regional heterogeneity, which, with age, becomes homogeneous again. Increasing inward conductance reduces OPC proliferation, keeping OPCs in cell-cycle arrest, while synchronized neuronal activity reduces inward potassium conductance, lifting the brake on proliferation. [ABSTRACT FROM AUTHOR]

• A novel 3D N-doped graphene aerogel anode with abundant N was fabricated. • 3D N-doped graphene aerogel anode result in higher bioelectricity generation. • Possible enhanced mechanisms for the N-doped graphene aerogel anode were explored. • The novel anode had good biocompatibility for Geobacter soli enrichment. • N-doping significantly upregulated the conductive pili-related genes of Geobacter. Bioelectricity generation by electrochemically active bacteria has become particularly appealing due to its vast potential in energy production, pollution treatment, and biosynthesis. However, developing high-performance anodes for bioelectricity generation remains a significant challenge. In this study, a highly efficient three-dimensional nitrogen-doped macroporous graphene aerogel anode with a nitrogen content of approximately 4.38 ± 0.50 at% was fabricated using hydrothermal method. The anode was successfully implemented in bioelectrochemical systems inoculated with Shewanella oneidensis MR-1, resulting in a significantly higher anodic current density (1.0 A/m2) compared to the control one. This enhancement was attributed to the greater biocapacity and improved extracellular electron transfer efficiency of the anode. Additionally, the N-doped aerogel anode demonstrated excellent performance in mixed-culture inoculated bioelectrochemical systems, achieving a high power density of 4.2 ± 0.2 W/m², one of the highest reported for three-dimensional carbon-based bioelectrochemical systems to date. Such improvements are likely due to the good biocompatibility of the N-doped aerogel anode, increased extracellular electron transfer efficiency at the bacteria/anode interface, and selectively enrichment of electroactive Geobacter soli within the NGA anode. Furthermore, based on gene-level Picrust2 prediction results, N-doping significantly upregulated the conductive pili-related genes of Geobacter in the three-dimensional anode, increasing the physical connection channels of bacteria, and thus strengthening the extracellular electron transfer process in Geobacter. [Display omitted] [ABSTRACT FROM AUTHOR]

Sulfadiazine (SDZ) is frequently detected in environmental samples, arousing much concern due to its toxicity and hard degradation. This study investigated the electricity generation capabilities, SDZ removal and microbial communities of a highly efficient mixed-culture system using repeated transfer enrichments in a bio-electrochemical system. The mixed-culture biofilm (S160-T2) produced a remarkable current density of 954.12 ± 15.08 μA cm−2 with 160 mg/L SDZ, which was 32.9 and 1.8 times higher than that of Geobacter sulfurreducens PCA with 40 mg/L SDZ and without additional SDZ, respectively. Especially, the impressive SDZ removal rate of 98.76 ± 0.79% was achieved within 96 h using the further acclimatized mixed-culture. The removal efficiency of this mixed-culture for SDZ through the bio-electrochemical system was 1.1 times higher than that using simple anaerobic biodegradation. Furthermore, the current density and removal efficiency in this system gradually decreased with increasing SDZ concentrations from 0 to 800 mg/L. In addition, community diversity data demonstrated that the dominant genera, Geobacter and Escherichia-Shigella , were enriched in mixed-culture biofilm, which might be responsible for the current production and SDZ removal. This work confirmed the important roles of acclimatized microbial consortia and co-substrates in the simultaneous removal of SDZ and electricity generation in an electrochemical system. • Higher electricity generation coupling with sulfadiazine removal was realized by the enriched mixed-cultures. • Mixed-culture biofilm (S160-T2) showed efficient dual-function ability of sulfadiazine removal and electricity production. • Geobacter and Escherichia-Shigella were selectively enriched in the S160-T2. [ABSTRACT FROM AUTHOR]

• We provide evidence of intra- and inter-filamentary mass diffusion-based communication in Oscillatoria sp. driven by Ca2+. • Large porous PU/PEDOT:PSS electrodes enabled detection of bioelectricity in Oscillatoria sp. cohorts. • We conclude that chemical paracrine signalling mediates electrogenic communication in cyanobacteria cohorts. Increasing frequency of poor water quality events associated with cyanobacteria strains capable of producing taste and odour (T&O) metabolites and toxins is a global concern for human health and the drinking water industry. This is mostly due to the inability of timely detecting and predicting cyanobacteria productivity associated with water quality risks. Here, we develop and characterize an ultra-sensitive electrophysiology system based on porous polyurethane (PU) foams coated with poly (3, 4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT: PSS) exploiting large-area electrodes of 199 cm2, which maximizes the double-layer capacitance and concomitant detection sensitivity. The measured signal of the cyanobacteria model taxa Oscillatoria sp. results from the sum of all individual cell contributions and scales with electrode area, hence indicating correlation with productivity and biomass. Stochastic activity across the cohort is monitored as uncorrelated noise. Yet, when Oscillatoria sp. operate cooperatively, the signal appears as intercellular Ca2+ waves which are benchmarked with a conventional fluorescent probe and suppressed with the specific ion channel inhibitor gadolinium chloride. We suggest the existence of a paracrine signaling mechanism with Ca2+ acting as the chemical messenger across large cohorts that may prove to be linked with T&O metabolite 2-Methylisoborneol (2-MIB) production. The technology proposed here would enable in-situ real time monitoring of benthic cyanobacteria productivity and hence proxy data for their metabolite production. This paves the way for identifying sources of cyanobacteria metabolites including 2-MIB, geosmin and cyanotoxins, and hence identify intervention solutions and treatment optimization for removal of these detrimental metabolites. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mixed-metal 3DOM ZIF was successfully synthesized. • CV results confirm a remarkable ORR activity for the FeTCPP doped electrocatalysts. • Multistage porous structure of 3DOM Fe,Co-NC allows facile diffusion of O 2. • Porous nature of 3DOM Fe,Co-NC enables higher performances of MFC. In this study, a porphyrin-based bimetallic zeolitic imidazole framework (FeTCPP-Zn/Co ZIF) was tailored via the reaction of Fe(III) meso -tetra(4-carboxyphenyl)porphyrin (FeTCPP), Zn(NO 3) 2 , and Co(NO 3) 2 , in the presence of 2-methylimidazole to prepare a M−N architecture with abundant active sites for electrocatalytic reduction of oxygen. Nano-sized polystyrene spheres were utilized as a precursor to develop three-dimensionally ordered macro-microporous (3DOM) FeTCPP-Zn/Co ZIF. Direct pyrolysis was adopted to obtain 3DOM Fe,Co-NC in order to enhance electrocatalytic performance toward the oxygen reduction reaction (ORR). The FE-SEM images revealed a unique porous morphology for the produced 3DOM Fe,Co-NC, offering a favorable environment for enhancing ORR kinetics due to the substantial availability of active sites. Electrochemical investigation revealed that the 3DOM Fe,Co-NC highlighted a higher level of ORR performance when compared to Fe,Co-NC. This superiority can be attributed to the 3DOM architecture, which enhances the efficiency of charge transportation. Further investigation of the prepared catalysts was performed using a dual-chamber microbial fuel cell (MFC). The MFC-3DOM Fe,Co-NC demonstrated a high power density of 147. 1 mW m−2 compared with the MFC-Fe,Co-NC (107.1 mW m−2). In this study, the importance of engineering design in developing porous structures was well-proven. [ABSTRACT FROM AUTHOR]

Bioenergy is a renewable energy alternative to fossil fuels, offering a means to reduce GHG emissions and support sustainable development in rural areas. Türkiye possesses diverse biomass resources, well-suited for electricity generation. By comprehensive data collection, we projected the long-term potential of each biomass type and assessed its contribution to the country's clean energy goals. Our analysis encompassed the potential of various sustainable biomass resources, including animal manure, municipal organic waste, sewage sludge, crop residues and firewood. In the modeled reference scenario following the country's energy targets, the share of renewables in electricity generation increases to 73% and with more ambitious biomass utilization, this share could be elevated to 82% by 2050, potentially reducing GHG emissions by 96.6 million ton of CO 2 eq. The findings of this study provide valuable insights for policymakers, demonstrating the extent to which sustainable bioenergy can contribute to shaping the electricity supply mix and influence long-term energy goals. It also helps in identifying crucial feedstock types for substantial bioenergy production, thus contributing to the progress of decarbonized development. • In the modeled reference scenario aligned with Türkiye's energy targets, the share of renewables in electricity generation increases to 73% and more ambitious biomass utilization could elevate this to 82% by 2050. • Bioelectricity has the capacity to meet up to 16% of the country's total electricity demand by 2050. • Applying the highest bioenergy demand scenario can avoid 96.6 million tons of CO2 equivalent over the projection period, contributing to a substantial 73% reduction relative to base year emissions. [ABSTRACT FROM AUTHOR]

Microbial fuel cells (MFCs) can generate electricity to drive electro-Fenton (EF) reactions for contaminant degradation. The oxygen reduction ability, catalytic ability, electron transfer efficiency, and styrene degradation efficiency of the catalysts were evaluated by loading iron and manganese ions on graphite fiber (GF) as bimetallic catalysts on the cathode of MFC/EF. The surface-loaded Fe–Mn@GF cathode had the highest reduction peak current density (−136.64 mA/cm2), which was 1.99 times that of the Fe@GF (−68.62 mA/cm2) cathode and 16.64 times that of the GF (−8.21 mA/cm2) cathode. Polymorphic crystals of Fe 2 O 3 and MnO 2 were observed in the Fe–Mn@GF-loaded cathode, resulting in many active sites on the surface of the cathode to enhance the catalytic ability of the material. The maximum power density (469.71 mW/m2) and minimum total internal resistance (189.63 Ω) of Fe–Mn@GF as the MFC cathode demonstrated that the Mn-doped cathode has superior electrical conductivity and electron transfer rate, thus significantly decreasing the electron transfer resistance. The styrene removal efficiency of MFC/EF using Fe–Mn@GF in a three-cycle run was maintained at over 90.31 %−98.14 %. The bimetallic catalyst effectively promoted hydrogen peroxide (H 2 O 2) generation, demonstrating that the Fe–Mn@GF system could stably produce ·OH for styrene degradation, and that MFC/EF with Fe–Mn@GF had almost no remaining biotoxicity after the first run. The most novel aspect of this study is the successful application of the MFC/EF system for styrene removal, providing a new approach for treating organic pollutants. Establishing this technology has important application value for improving water quality and environmental protection. [Display omitted] • Microbial fuel cell is combined with the Fenton process to degrade styrene. • Modified Fe–Mn@GF catalyst enhances the catalytic ability of cathode materials. • The synergistic effect of Fe and Mn improves the reduction ability of catalysts. • Fe–Mn@GF promotes the generation of H 2 O 2 and OH• to degrade styrene. [ABSTRACT FROM AUTHOR]

Background. Plant-microbial fuel cell (PMFC) is an innovative biotechnology for the environmentally safe bioelectricity generation. The widespread use of bioelectrical systems (biosystems) is hindered by their insufficient efficiency due to limiting knowings of the relationship between bioelectricity generation and features of their biotechnological components. Objective. Тhe purpose of this study was to analyze the role of the plants morphological parameters and structure features of biomodules on generation of bioelectricity. Methods. Biometric, biogravimetric, voltammetric, and statistical analysis methods were used to assess the relationship between plant`s accumulated mass of leaf and roots, multielectrode design of biosystem and bioelectricity generation. Results. PMFC based on sedge C. hirta with the largest accumulated total dry leaf/stem and root mass and also the rhizome-like and developed fibrous root system were characterized by the highest power output compared to other biosystems. The power density was 970 ± 22 mW m-2 PGA. The parallel stacking of biomodules leads to obtain current output about 108.7 mA. That is why the developed biotechnological systems can be recommended as a foundation for the development of power supply for WiFi microcontrollers that consume 100 mA or for charging batteries. Conclusions. Sedge С. hirta were appeared as the more suitable plants for biological component of biosystem of bioelectricity generation. Power density of С. hirta based PMFC exceeded the one of based on other plants in 9.3–37.9%.The type and level of development of the root system and of the above-ground photosynthetic surface of plant are an important prognostic factors of the PMFC perfomance. A 10-fold increase of the electrode surface of one biomodule results in 3.95 times increase of power density at 200 W. The multielectrodeity biomodule reveals as another lever for increasing the efficiency of biosystems which allows obtaining significantly increase power density and current density in the range of electrical resistance from 50 to 500 W.

Abstract Recent studies have shown that bacterial membrane potential is dynamic and plays signaling roles. Yet, little is still known about the mechanisms of membrane potential dynamics regulation—owing to a scarcity of appropriate research tools. Optical modulation of bacterial membrane potential could fill this gap and provide a new approach for studying and controlling bacterial physiology and electrical signaling. Here, the authors show that a membrane‐targeted azobenzene (Ziapin2) can be used to photo‐modulate the membrane potential in cells of the Gram‐positive bacterium Bacillus subtilis. It is found that upon exposure to blue–green light (λ = 470 nm), isomerization of Ziapin2 in the bacteria membrane induces hyperpolarization of the potential. To investigate the origin of this phenomenon, ion‐channel‐deletion strains and ion channel blockers are examined. The authors found that in presence of the chloride channel blocker idanyloxyacetic acid‐94 (IAA‐94) or in absence of KtrAB potassium transporter, the hyperpolarization response is attenuated. These results reveal that the Ziapin2 isomerization can induce ion channel opening in the bacterial membrane and suggest that Ziapin2 can be used for studying and controlling bacterial electrical signaling. This new optical tool could contribute to better understand various microbial phenomena, such as biofilm electric signaling and antimicrobial resistance.

In this study, wastewater was analyzed for the presence of the antibiotics, tetracycline (Tet) and chloramphenicol (Chlor). Additionally, the antibiotic removal capacities of constructed wetland systems, with interacting macrophytes (Lemna gibba and Azolla filiculoides), substrates (sand and silt) and with or without microbial fuel cells (MFCs), were examined. To find the ideal wetland combination, a randomized 23 factorial design was applied, resulting in eight combinations in triplicate. The initial and final concentrations of antibiotics in the aquatic medium and in plants at the end of the experiment were measured with a high-performance liquid chromatography-diode array detector (HPLC-DAD) to verify the absorption rate. The results showed average Tet and Chlor concentration in wastewater samples 4.25 ± 3.95 and 1.87 ± 0.07 μg/L, respectively. All wetland types performed efficiently, removing a maximum of 100% tetracycline and chloramphenicol and a minimum of 99.45% and 97.84% Tet and Chlor, respectively. The average absorption of Tet and Chlor was 3.13 and 0.36 μg/g, respectively, in A. filiculoides; and the average absorption of Tet and Chlor was 2.08 and 0.08 μg/g, respectively, in Lemna. L. gibba had a higher biomass increase and a better relative growth rate than Azolla. In relation to electrical production, at first, all treatments were affected by the antibiotics; however, production increased as time progressed. Finally, the physicochemical parameters that improved with treatment were oxygen, oxidation-reduction potential and pH, whereas conductivity, dissolved solids, and salinity were most influenced by the silt substrate. Overall, although no wetland was ideal, all combinations were efficient at removing antibiotic contaminants.

Biofuels hold particular promise as these can replace fossil fuels. Algae, in particular, are envisioned as a sustainable source of third-generation biofuels. Algae also produce several low volume high-value products, which enhance their prospects of use in a biorefinery. Bio-electrochemical systems such as microbial fuel cell (MFC) can be used for algae cultivation and bioelectricity production. MFCs find applications in wastewater treatment, CO2 sequestration, heavy metal removal and bio-remediation. Oxidation of electron donor by microbial catalysts in the anodic chamber gives electrons (reducing the anode), CO2, and electrical energy. The electron acceptor at the cathode can be oxygen/NO3-/NO2-/metal ions. However, the need for a continuous supply of terminal electron acceptor in the cathode can be eliminated by growing algae in the cathodic chamber, as they produce enough oxygen through photosynthesis. On the other hand, conventional algae cultivation systems require periodic oxygen quenching, which involves further energy consumption and adds cost to the process. Therefore, the integration of algae cultivation and MFC technology can eliminate the need of oxygen quenching and external aeration in the MFC system and thus make the overall process sustainable and a net energy producer. In addition to this, the CO2 gas produced in the anodic chamber can promote the algal growth in the cathodic chamber. Hence, the energy and cost invested for CO2 transportation in an open pond system can be saved. In this context, the present review outlines the bottlenecks of first- and second-generation biofuels along with the conventional algae cultivation systems such as open ponds and photobioreactors. Furthermore, it discusses about the process sustainability and efficiency of integrating algae cultivation with MFC technology in detail.

The microbial fuel cell (MFC) is an ecologically friendly alternative energy source. Due to the typically limited electron transfer in MFC systems, co-biocatalysts are necessary to enhance their performance. Enzymes are used as co-biocatalysts due to their superior ability to generate energy, and the system is known as an enzymatic microbial fuel cell (EMFC). One of the substrates that may be used is bagasse waste extracted from sugarcane. Saccharo­myces cerevisiae and the enzyme glucose oxidase (GOx) serve as co-biocatalysts in the breakdown of sugarcane bagasse waste in this study, which uses single-chamber EMFCs. In EMFC using sugarcane bagasse waste extract employing S. cerevisiae biocatalyst and glucose oxidase enzyme co-biocatalyst, the open circuit voltage was 0.56 V and the maximum power density was 146.65 mW m-2, an increase of 10.4 times to MFCs that solely employed only yeast biocatalyst. In addition, the chemical oxygen demand (COD) reduction achieved by this technology is 75 %. In addition, the pH of sugarcane bagasse waste extract samples treated with Saccharomyces cerevisiae yeast and GOx enzyme decreased from 4.6 to 4.2. This research demonstrates that adding the co-biocatalyst GOx enzyme may boost the performance of the traditional yeast MFC.

Microbial fuel cells (MFCs), unique biosystems that generate energy through exoelectrogens, have undergone significant development in the last decades. Although MFCs have great prospects in environmental protection and power generation, there are still problems of inefficiency and high cost, which are largely attributed to the low performance of anode materials used in MFCs because the anode plays a crucial role in MFCs as a carrier for microbial attachment. In the last few years, researchers have shown great interest in developing advanced anode materials to enhance the performance of MFCs. Herein, an overview of recent progress in the development of anode materials for MFCs is offered. In addition, novel anode modification strategies are summarized. Finally, challenges and development directions of next‐generation anode materials with the potential to finally enable the commercial application of MFCs are discussed. [ABSTRACT FROM AUTHOR]

Bioelectricity is defined as endogenous electrical signaling mediated by the dynamic distribution of charged molecules. Recently, increasing evidence has revealed that cellular bioelectric signaling is critical for regulating embryonic development, regeneration, and congenital diseases. However, systematic real-time in vivo dynamic electrical activity monitoring of whole organisms has been limited, mainly due to the lack of a suitable model system and voltage measurement tools for in vivo biology. Here, we addressed this gap by utilizing a genetically stable zebrafish line, Tg (ubiquitin: ASAP1), and ASAP1 (Accelerated sensor of action potentials 1), a genetically encoded voltage indicator (GEVI). With light-sheet microscopy, we systematically investigated cell membrane potential (Vm) signals during different embryonic stages. We found cells of zebrafish embryos showed local membrane hyperpolarization at the cleavage furrows during the cleavage period of embryogenesis. This signal appeared before cytokinesis and fluctuated as it progressed. In contrast, whole-cell transient hyperpolarization was observed during the blastula and gastrula stages. These signals were generally limited to the superficial blastomere, but they could be detected within the deeper cells during the gastrulation period. Moreover, the zebrafish embryos exhibit tissue-level cell Vm signals during the segmentation period. Middle-aged somites had strong and dynamic Vm fluctuations starting at about the 12-somite stage. These embryonic stage-specific characteristic cellular bioelectric signals suggest that they might play a diverse role in zebrafish embryogenesis that could underlie human congenital diseases. [ABSTRACT FROM AUTHOR]

Bioenergy is being increasingly used worldwide to generate energy from biogas, biomethane, and other biofuels, bringing significant environmental and economic benefits. In Italy, biogas can significantly contribute to the achievement of the renewable energy targets set at the national and European levels. The exploitation of this energy source in a particular area is determined by its environmental and anthropic properties, as well as by the incentive system and the political will of decision makers. This paper analyzes the socioeconomic drivers and natural conditions triggering bioelectricity production in Italian regions. The analysis proposed here was performed in two steps—first, by identifying groups of similar regions for some natural, social, and economic variables, and then by modeling the historical trajectory of bioelectricity production for each identified group with innovation diffusion models. As a general finding, regions pertaining to the same group in terms of natural and socioeconomic conditions revealed a similar production pattern for bioelectricity, as confirmed by the results of diffusion modeling. On the basis of the diffusion modeling procedure, some scenario simulations were performed, which suggested the set-up of suitable policy actions for each group of regions. [ABSTRACT FROM AUTHOR]

Organogenesis is a complex process that can be disrupted by embryonic exposure to teratogens or mutation‐induced alterations in signalling pathways, both of which result in organ mispatterning. Building on prior work in Xenopus laevis that showed that increased HCN2 ion channel activity rescues nicotine‐induced brain and eye morphogenesis, we demonstrate much broader HCN2‐based rescue of organ patterning defects. Induced HCN2 expression in both local or distant tissues can rescue CNS (brain and eye) as well as non‐CNS (heart and gut) organ defects induced by three different teratogenic conditions: nicotine exposure, ethanol exposure or aberrant Notch protein. Rescue can also be induced by small‐molecule HCN2 channel activators, even with delayed treatment initiation. Our results suggest that HCN2 (likely mediated by bioelectric signals) can be an effective regulator of organogenesis from all three germ layers (ectoderm, mesoderm and endoderm) and reveal non‐cell‐autonomous influences on organ formation that work at a considerable distance during embryonic development. These results suggest molecular bioelectric strategies for repair that could be explored in the future for regenerative medicine. [ABSTRACT FROM AUTHOR]

The excessive use of fossil sources for the generation of electrical energy and the increase in different organic wastes have caused great damage to the environment; these problems have promoted new ways of generating electricity in an eco-friendly manner using organic waste. In this sense, this research uses single-chamber microbial fuel cells with zinc and copper as electrodes and pineapple waste as fuel (substrate). Current and voltage peaks of 4.95667 ± 0.54775 mA and 0.99 ± 0.03 V were generated on days 16 and 20, respectively, with the substrate operating at an acid pH of 5.21 ± 0.18 and an electrical conductivity of 145.16 ± 9.86 mS/cm at two degrees Brix. Thus, it was also found that the internal resistance of the cells was 865.845 ± 4.726 Ω, and a maximum power density of 513.99 ± 6.54 mW/m2 was generated at a current density of 6.123 A/m2, and the final FTIR spectrum showed a clear decrease in the initial transmittance peaks. Finally, from the biofilm formed on the anodic electrode, it was possible to molecularly identify the yeast Wickerhamomyces anomalus with 99.82% accuracy. In this way, this research provides a method that companies exporting and importing this fruit may use to generate electrical energy from its waste. [ABSTRACT FROM AUTHOR]

The microbial fuel cell (MFC) is considered as a renewable, non-toxic, reliable, clean, efficient, and also an alternative source for bioenergy. It provides numerous opportunities to improve sustainable applications in various sites, ranging from industrial to home. The low power output of microbial fuel cells is one of the important factors that hinder their commercialization. Power outputs must be improved to contribute to the commercialization of MFCs. In this study, organic peat material was used as a substrate for a double chamber MFC. In addition, since Clostridium bacteria were detected in the organic peat material, an additional bacterial strain was not used. In this MFC application, where graphite is used as both anode and cathode electrodes, 1 mol/L NaOH solution was employed as the cathode chamber solution. This peat-based MFC provided the highest electrical power density of 438.116 mW/m2. The most important limiting factor of the peat-based MFC was the spreading of the NaOH solution throughout the cell due to the rupture of the proton exchange membrane after 9 h of operation. [ABSTRACT FROM AUTHOR]

Sodium bicarbonate (NaHCO3) is a low-cost inorganic carbon source, highly soluble in water and widely used in microalgae research. Using carbon dioxide (CO2) gas in microalgae culture is ideal for algae growth. However, the usage of CO2 is restricted due to the high cost of CO2 capture and transportation. In this work, the performance of non-axenic Chlorella sp. (UKM2) biofilms on fluorine doped tin oxide (FTO) glass anodes with varying NaHCO3 concentrations in the biophotovoltaic (BPV) systems is measured and discussed. The highest power density and photosynthetic pigments were obtained when employing 1 g L−1 NaHCO3 in the system. The presence of NaHCO3 increased the photosynthetic pigments e.g., chlorophyll-a and improved the performance of the BPV system. The power output increased by 52% from day 6 (0.023 ± 0.005 mW m−2) to day 12 (0.035 ± 0.003 mW m−2). After 12 days of operation, the power output of 0.035 ± 0.003 mW m−2 was generated, and the system still operated even after 50 days. For the long-term performance of BPV device, the highest power output of 0.042 ± 0.003 mW m−2 was obtained for the 1 g L−1 NaHCO3 system which corresponds to 83% increment from day 6 to day 55. However, an excessive amount of NaHCO3 concentration deteriorated the performance due to the reduction of chlorophyll-a concentration. [ABSTRACT FROM AUTHOR]

A large amount of fruit waste is being a great environmental and social problem due to a lack of adequate storage. Among the most abundant waste is papaya, due to its high consumption in various varieties. These wastes can generate bioelectricity through organic waste, being an important parameter the pH. In this research, lowcost laboratory-scale microbial fuel cells were fabricated, using papaya waste as fuel at different pH (4, 5.73, 7, and 9) to obtain the optimum operating pH. It was possible to observe the maximum values of electric current and voltage of 17.97 mA and 1.02 V on days 16 and 14, in the cell with pH 7; while the cell with pH was the one that showed the lowest values. The electrical conductivity values increased from the first day, observing a maximum peak of 172.50 mS/cm for the cell with pH 7. However, the internal resistance values were low, the maximum value being for the cell with pH 4 (234.61 ± 34 Ω) and the minimum for the cell with pH 7 (46.543 ± 3.6 Ω). In the same way, the maximum power density was for the cell with pH 7 of approximately 645.74 ± 33.64 mW/cm2 and a current density of 5.42 A/cm². [ABSTRACT FROM AUTHOR]

This study deals with the fabrication of a low‐cost ceramic anode made by blending the rice husk and mild steel dust with soil (RMS anode) for its application in plant microbial fuel cells (PMFCs). The high cost of electrode material has been a major concern in practical applications of the PMFC technology, but the present composition of waste materials such as rice husk, mild steel dust along with soil has served as an alternative low‐cost electrode material. Tagetes erecta plant has been used to produce clean and continuous electrical energy in the PMFC. The blending of rice husk has improved the porosity of the ceramic anode. The maximum power density recorded in PMFC with 50% rice husk anode was 1.4 mW/m2 as against 0.26 mW/m2 with the anode without rice husk. High biomass growth in terms of better plant height and higher chlorophyll content was also detected in the PMFC system within 60 working days. [ABSTRACT FROM AUTHOR]

Piezoelectric, conductive, and injectable hydrogel (SPG hydrogel) is constructed to rapidly close wounds, efficiently harvest biomechanical energy from animal motion, and generate electrical stimulation for electrotherapy of wound healing. 3-amino-4-methoxybenzoic acid (AMB) monomer was polymerized and grafted onto the gelatin, which was further crosslinked using EDC/NHS and embedded with strontium titanate nanoparticles (80.5 wt%), forming SPG hydrogel. This SPG hydrogel had high tissue adhesion ability, and could generate the output voltage (maximum output voltage 1 V) and current (maximum output current 0.5 nA) upon mechanical bending, promoting NIH-3T3 cell migration and proliferation. Upon application to the mice wound model, the SPG hydrogel rapidly closed the skin wound, smoothed the wound's appearance, reduced the remaining wound size, and increased epidermal thickness, demonstrating remarkable wound healing capabilities. This study suggests that the body motion-promoted electrotherapy offers a promising strategy for wound healing. STATEMENT OF SIGNIFICANCE: Piezoelectric nanomaterials are often incorporated into hydrogels to create piezoelectric hydrogels for wound healing. However, piezoelectric nanomaterials tend to agglomerate within the hydrogel matrix, and the hydrogel's low conductivity hinders efficient electron transfer. Together, both factors significantly reduce the piezoelectric effect. In this study, we developed an SPG hydrogel to improve the homogeneity and conductivity of the piezoelectric hydrogel. We first designed a conductive PG hydrogel and then immoblized piezoelectric STO nanoparticles within its matrix through coordination chemistry. Upon mechanical deformation, the uniformly distributed STO nanoparticles can generate electricity, which can efficiently transfer through the conductive matrix to the hydrogel's surface. This design shows great potential for wound healing applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Plant microbial fuel cell (PMFC) is an emerging technology, showing promise for environmental biosensors and sustainable energy production. Despite its potential, PMFCs struggle with issues like low power output and limited drought resistance. Recent studies proposed that integrating biochar may enhance PMFC performance due to its physicochemical properties. The influence of different biochar types on PMFC efficiency has been minimally explored. This study aims to fill this gap by evaluating the performance of PMFCs integrated with various biochar types under unsaturated soil conditions. The study found that the addition of biochar types─specifically reed straw biochar (RSB), apple wood biochar (AWB), and corn straw biochar (CSB)─significantly influenced the performance of PMFCs. RSB, with its large surface area and porous structure, notably increased the current output by reducing soil resistance and enhancing electron transfer efficiency in microbial reduction reactions, achieving a peak power density of approximately 1608 mW/m 2 . AWB, despite its less porous structure, leveraged its high cation exchange capacity and hydrophilic functional groups to foster microbial community growth and diversity, thereby also increasing bioelectricity output. Conversely, CSB, with its large surface area, showed the least improvement in PMFC performance due to its layered structure and lower water retention capacity. Additionally, under drought conditions, PMFCs with added RSB and AWB exhibited better drought resistance due to their ability to improve soil moisture characteristics and enhance soil conductivity. The addition of biochar reduced soil resistance, increasing the bioelectric output of PMFCs and maintaining good performance even under low moisture conditions. This study highlights the critical role of biochar's surface area and functional groups in optimizing PMFC performance. It enhances our understanding of PMFC optimization and might offer a novel power generation method for the future, while also presenting a fresh strategy for soil monitoring.

Plant microbial fuel cells represent an innovative type of microbial fuel cell technology, utilizing plant rhizodeposition to fuel electrochemically active bacteria on the anode surface, thereby generating bioelectricity. This study delves into some botanical aspects of plant species employed in PMFCs and Constructed Wetland PMFCs, aiming to investigate whether their bioelectrical performance is influenced by Raunkiær life forms and root architecture. Our study involved 40 plant species described in 38 documents. In some cases, nomenclature issues prevented the interpretation of actual species used in the experiments. The bioelectrical performance of PMFCs appeared to be significantly affected by both life forms and root architecture. Therophytes and Hemicriptophytes exhibited higher median values than the other life forms, while the Geophyte group showed very high power density values despite a lower median value. In contrast, CW-PMFCs do not appeared to be significantly affected by the botanical traits considered, likely due to the limited data collected on this experimental configuration. The plant species that performed the best in PMFCs include Carex hirta , Alisma plantago-aquatica , Glyceria maxima and Canna indica , all of which have an adventitious root system. C. hirta , G. maxima and C. indica are geophytes, while A. plantago-aquatica is a hydrophyte. Consequently, epiphytes, chamaephytes and nanophanerophytes, as well as plants with fibrous root systems, appeared to be not recommended for PMFCs. Nevertheless, the results of our study may have certain limitation due to nomenclature issues that prevented the accurate identification of species used in the PMFCs, the absence of a standardized benchmark for electrical measurement, and the lack of clear match between each species and its bioelectrical performance, reducing the data pool., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Conductive biomaterials may capture native or exogenous bioelectric signaling, but incorporation of conductive moieties is limited by cytotoxicity, poor injectability, or insufficient stimulation. Microgel annealed scaffolds are promising as hydrogel-based materials due to their inherent void space that facilitates cell migration and proliferation better than nanoporous bulk hydrogels. Conductive microgels are generated from poly(ethylene) glycol (PEG and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS) to explore the interplay of void volume and conductivity on myogenic differentiation. PEDOT: PSS increases microgel conductivity two-fold while maintaining stiffness, annealing strength, and viability of associated myoblastic cells. C2C12 myoblasts exhibit increases in the late-stage differentiation marker myosin heavy chain as a function of both porosity and conductivity. Myogenin, an earlier marker, is influenced only by porosity. Human skeletal muscle-derived cells exhibit increased Myod1, insulin like growth factor-1, and insulin-like growth factor binding protein 2 at earlier time points on conductive microgel scaffolds compared to non-conductive scaffolds. They also secrete more vascular endothelial growth factor at early time points and express factors that led to macrophage polarization patterns observe during muscle repair. These data indicate that conductivity aids myogenic differentiation of myogenic cell lines and primary cells, motivating the need for future translational studies to promote muscle repair., (© 2023 The Authors. Advanced Healthcare Materials published by Wiley‐VCH GmbH.)