Liping Huang, Shiping Song, Zhenghong Cai et al.

Chemical Engineering Journal • 2020

Xiaoyuan Xue, Zhuangzhuang Liu, Wenfang Cai et al.

Bioresource Technology Reports • 2022

Khurram Tahir, Nagesh Maile, Ahsan Abdul Ghani et al.

Bioelectrochemistry • 2022

Priyanka Gupta, Nishith Verma

Chemical Engineering Journal • 2022

Donglin Wang, Qinjun Liang, Na Chu et al.

Chemical Engineering Journal • 2022

Xiaomin Li, Long‐Jun Ding, Dong Zhu et al.

Environmental Science & Technology • 2021

Electrotrophs play an important role in biogeochemical cycles, but the effects of long-term fertilization on electrotrophic communities in paddy soils remain unclear. Here, we explored the responses of electrotrophic communities in paddy soil-based microcosms to different long-term fertilization practices using microbial electrosynthesis systems (MESs), high-throughput quantitative PCR, and 16s rRNA gene-based Illumina sequencing techniques. Compared to the case in the unfertilized soil (CK), applications of only manure (M); only chemical nitrogen, phosphorous, and potassium fertilizers (NPK); and M plus NPK (MNPK) clearly changed the electrotrophic bacterial community structure. The Streptomyces genus of the Actinobacteria phylum was the dominant electrotroph in the CK, M, and MNPK soils. The latter two soils also favored Truepera of Deinococcus-Thermus or Arenimonas and Thioalkalispira of Proteobacteria. Furthermore, Pseudomonas of Proteobacteria and Bacillus of Firmicutes were major electrotrophs in the NPK soil. These electrotrophs consumed biocathodic currents coupled with nitrate reduction and recovered 18-38% of electrons via dissimilatory nitrate reduction to ammonium (DNRA). The increased abundances of the nrfA gene for DNRA induced by electrical potential further supported that the electrotrophs enhanced DNRA for all soils. These expand our knowledge about the diversity of electrotrophs and their roles in N cycle in paddy soils and highlight the importance of fertilization in shaping electrotrophic communities.

Abraham Gomez Vidales, Sasha Omanovic, Hongbo Li et al.

Bioelectrochemistry • 2022

Qinjun Liang, Yu Gao, Zhigang Li et al.

Frontiers of Environmental Science & Engineering • 2021

Su Hui, Yujing Jiang, Yuan-Fan Jiang et al.

Energy Materials • 2023

Microbial electrosynthesis (MES) is an emerging technology that enables the synthesis of value-added chemicals from carbon dioxide (CO2) or inorganic carbon compounds by coupling renewable electricity to microbial metabolism. However, MES still faces challenges in achieving high production of value-added chemicals due to the limited extracellular electron transfer efficiency at the biotic-abiotic interfaces. To overcome this bottleneck, it is crucial to develop novel cathodes and modified materials. This review systematically summarizes recent advancements in cathode materials in the field of electrocatalyst-assisted and photocatalyst-assisted MES. The effects of various material types are further investigated by comparing metal-free and metal materials and photocatalyst materials of different semiconductor types. Additionally, the review introduces the maximum production rate of value-added chemicals and conversion efficiency achieved by these cathode materials while highlighting the advantages and disadvantages of different material types. To the best of our knowledge, in electrocatalyst-assisted systems, the maximum CH4 yield on graphene aerogel/polypyrrole cathode achieved 1,672 mmol m-2 d-1, and the maximum Faraday efficiency (FE) of CH4 reached up to 97.5% on graphite plate. Meanwhile, the maximum acetate yield achieved 1,330 g m-2 d-1 with CO2 conversion efficiency into acetate close to 100% on carbon nanotube cathodes. In photocatalyst-assisted systems, the maximum acetate yield could reach 0.51 g L-1 d-1 with the coulombic efficiency of 96% on the MnFe2O4/g-C3N4 photocathode. Finally, prospects for future development and practical applications of MES are discussed, offering theoretical guidance for the fabrication of cathode materials that can improve production efficiency and reduce energy input.

Kang Zhang, Yonghang Zhou, Tian‐shun Song et al.

Energy & Fuels • 2021

Microbial electrosynthesis (MES) is an emerging technology that uses electricity and biocatalysts to reduce CO2 and produce organic commodities. To improve the added value of MES products, we used the MES product of Ralstonia eutropha to generate polyhydroxybutyrate (PHB), a type of bioplastic. The first step was to generate a certain concentration of acetate in MES. The second step was to use acetate at the concentration produced by MES as a substrate for PHB generation by R. eutropha. Simultaneously, we compared the effects of acetate produced by double-chamber and triple-chamber MES reactors on PHB production. Lastly, 0.460 g/L PHB was produced ex situ from 5 g/L acetate in the triple-chamber MES reactor by R. eutropha. This PHB yield was the highest among all of the experimental groups. In MES, the composition and salinity of a product will affect the synthesis of PHB. This study provides a method for generating bioplastics using products from the bioelectrochemical reduction of CO2.

Rashmi Kiran, Ravineet Yadav, Devangi Sathe et al.

Bioresource Technology • 2023

Yuting He, Jun Li, Liang Zhang et al.

Chemical Engineering Journal • 2023

Shihao Tian, Xiaoyue Yao, Tian‐shun Song et al.

ACS Sustainable Chemistry & Engineering • 2020

Microbial electrosynthesis (MES) is an emerging strategy for converting electrical energy into chemical energy. Many efforts have been made toward the enhancement of cathode-microorganism interactions and electron transfer by modifying cathodic materials; however, high electrochemical activity and good biocompatibility have often not been available at the same time in previously reported materials. Here, we deliver a novel MES bioreactor by designing a well-defined Prussian blue nanocube-modified carbon felt (PBNC-CF) as an artificial electron mediator-decorated cathode for organic molecule production from a CO2 source. Because of the rapid electronic transition between Fe2+ to Fe3+ atoms in a unit cell, PBNCs significantly improve the electrochemical activity of the cathode by dramatically increasing the electron supply to electroautotrophic microorganisms. This modification also enhances the biocatalytic activity by regulating the composition of microbial community with the accumulation of acetogens such as Acetobacterium and the reduction of the electron-transferring bacterium, Arcobacter. Furthermore, the hydrophilicity and positive charge of PBNCs improve cathodic biocompatibility and are conducive to the growth of biofilms on the electrode surface and internal fibers. This strategy provides a new direction for MES electrode modification, showing that the development of an artificial electron mediator-based cathode is significantly important to improve MES efficiency.

Haifeng Huang, Haoqi Wang, Qiong Huang et al.

International Journal of Hydrogen Energy • 2021

Manal Alqahtani, Suman Bajracharya, Krishna P. Katuri et al.

Frontiers in Microbiology • 2019

Homoacetogens are efficient CO 2 fixing bacteria using H 2 as electron donor to produce acetate. These organisms can be enriched at the biocathode of microbial electrosynthesis (MES) for electricity-driven CO 2 reduction to acetate. Studies exploring homoacetogens in MES are mainly conducted using pure or mix-culture anaerobic inocula from samples with standard environmental conditions. Extreme marine environments host unique microbial communities including homoacetogens that may have unique capabilities due to their adaptation to harsh environmental conditions. Anaerobic deep-sea brine pools are hypersaline and metalliferous environments and homoacetogens can be expected to live in these environments due to their remarkable metabolic flexibility and energy-efficient biosynthesis. However, brine pools have never been explored as inocula for the enrichment of homacetogens in MES. Here we used the saline water from a Red Sea brine pool as inoculum for the enrichment of halophilic homoacetogens at the biocathode (-1 V vs. Ag/AgCl) of MES. Volatile fatty acids, especially acetate, along with hydrogen gas were produced in MES systems operated at 25 and 10% salinity. Acetate concentration increased when MES was operated at a lower salinity ∼3.5%, representing typical seawater salinity. Amplicon sequencing and genome-centric metagenomics of matured cathodic biofilm showed dominance of the genus Marinobacter and phylum Firmicutes at all tested salinities. Seventeen high-quality draft metagenome-assembled genomes (MAGs) were extracted from the biocathode samples. The recovered MAGs accounted for 87 ± 4% of the quality filtered sequence reads. Genome analysis of the MAGs suggested CO 2 fixation via Wood-Ljundahl pathway by members of the phylum Firmicutes and the fixed CO 2 was possibly utilized by Marinobacter sp. for growth by consuming O 2 escaping from the anode to the cathode for respiration. The enrichment of Marinobacter sp. with homoacetogens was only possible because of the specific cathodic environment in MES. These findings suggest that in organic carbon-limited saline environments, Marinobacter spp. can live in consortia with CO 2 fixing bacteria such as homoacetogens, which can provide them with fixed carbon as a source of carbon and energy.

Min‐Soo Kim, Shuwei Li, Young Eun Song et al.

Chemical Engineering Journal • 2022

Xiaochen Shi, Pier‐Luc Tremblay, Lulu Wan et al.

The Science of The Total Environment • 2020

Yixin Li, Qingliu Luo, Jiaying Su et al.

Metabolic Engineering • 2023

Kang Zhang, Zhenyu Qiu, Dan Luo et al.

Renewable Energy • 2022

Jie Zhang, He Liu, Yan Zhang et al.

Biochemical Engineering Journal • 2021

José Gavilanes, Md Tabish Noori, Booki Min

Bioresource Technology Reports • 2019

Ha T.T. Dinh, Hiromi Kambara, Shuji Matsushita et al.

Journal of Environmental Sciences • 2022

Sanne M. de Smit, Cees J.N. Buisman, Johannes H. Bitter et al.

ChemElectroChem • 2021

Abstract Cyclic voltammetry (CV) is expected to cause changes in the biocathode composition, especially when using low scan rates. A recent finding stated that CV triggered further biocatalytic activity in microbial electrosynthesis systems (MES), leading to the aim of our study: to investigate the invasiveness of CV on MES. The present study confirms that a CO 2 elongation MES biocathode composition changes during and right after the CV. Oxidation peaks differ over repeated CV‐cycles while metal compounds and biomass were released in the biocatholyte. After CV, the current increased temporarily for up to 20 days and the metal compounds decreased from the biocatholyte solution. Further, the sole short application of open cell voltage was shown to shortly increase the current. Evidently CV affects the studied biocathode, which complicates the use of CV as an analysis technique in MESs. However, the positive effect CV has on biocathode current density may provide methods to boost reactor performance and maintain productivity.

Ala’a Ragab, Dario Rangel Shaw, Krishna P. Katuri et al.

Scientific Reports • 2020

Microbial electrosynthesis exploits the catalytic activity of microorganisms to utilize a cathode as an electron donor for reducing waste CO 2 to valuable fuels and chemicals. Electromethanogenesis is the process of CO 2 reduction to CH 4 catalyzed by methanogens using the cathode directly as a source of electrons or indirectly via H 2 . Understanding the effects of different set cathode potentials on the functional dynamics of electromethanogenic communities is crucial for the rational design of cathode materials. Replicate enriched electromethanogenic communities were subjected to different potentials (- 1.0 V and - 0.7 V vs. Ag/AgCl) and the potential-induced changes were analyzed using a metagenomic and metatranscriptomic approach. The most abundant and transcriptionally active organism on the biocathodes was a novel species of Methanobacterium sp. strain 34x. The cathode potential-induced changes limited electron donor availability and negatively affected the overall performance of the reactors in terms of CH 4 production. Although high expression of key genes within the methane and carbon metabolism pathways was evident, there was no significant difference in transcriptional response to the different set potentials. The acetyl-CoA decarbonylase/synthase (ACDS) complex were the most highly expressed genes, highlighting the significance of carbon assimilation under limited electron donor conditions and its link to the methanogenesis pathway.

Raed Gharbi, Abraham Gomez Vidales, Sasha Omanovic et al.

Journal of CO2 Utilization • 2022

Jihua Zhao, Hongzhi Ma, Wenyu Wu et al.

Fuel • 2022

Abdullah Al-Mamun, Waqar Ahmed, Tahereh Jafary et al.

Biochemical Engineering Journal • 2023

Shuai Xiao, Qian Fu, Kerui Xiong et al.

Renewable Energy • 2020

Hui Wang, Hongxia Du, Haiyin Xie et al.

Bioresource Technology • 2021

Dayakar Thatikayala, Booki Min

The Science of The Total Environment • 2021

Xiaoting Zhang, Tyler Arbour, Daijun Zhang et al.

Environmental Science and Ecotechnology • 2022

Microbial electrosynthesis (MES) enables the bioproduction of multicarbon compounds from CO 2 using electricity as the driver. Although high salinity can improve the energetic performance of bioelectrochemical systems, acetogenic processes under elevated salinity are poorly known. Here MES under 35-60 g L -1 salinity was evaluated. Acetate production in two-chamber MES systems at 35 g L -1 salinity (seawater composition) gradually decreased within 60 days, both under -1.2 V cathode potential (vs. Ag/AgCl) and -1.56 A m -2 reductive current. Carbonate precipitation on cathodes (mostly CaCO 3 ) likely declined the production through inhibiting CO 2 supply, the direct electrode contact for acetogens and H 2 production. Upon decreasing Ca 2+ and Mg 2+ levels in three-chamber reactors, acetate was stably produced over 137 days along with a low cathode apparent resistance at 1.9 ± 0.6 mΩ m 2 and an average production rate at 3.80 ± 0.21 g m -2 d -1 . Increasing the salinity step-wise from 35 to 60 g L -1 gave the most efficient acetate production at 40 g L -1 salinity with average rates of acetate production and CO 2 consumption at 4.56 ± 3.09 and 7.02 ± 4.75 g m -2 d -1 , respectively. The instantaneous coulombic efficiency for VFA averaged 55.1 ± 31.4%. Acetate production dropped at higher salinity likely due to the inhibited CO 2 dissolution and acetogenic metabolism. Acetobacterium up to 78% was enriched on cathodes as the main acetogen at 35 g L -1 . Under high-salinity selection, 96.5% Acetobacterium dominated on the cathode along with 34.0% Sphaerochaeta in catholyte. This research provides a first proof of concept that MES starting from CO 2 reduction can be achieved at elevated salinity.

Yong Jiang, Qinjun Liang, Na Chu et al.

The Science of The Total Environment • 2020

Zhigang Li, Jiayi Cai, Yu Gao et al.

Bioresource Technology • 2022

Shihao Tian, Juan He, Haifeng Huang et al.

ACS Applied Materials & Interfaces • 2020

Microbial electrosynthesis (MES) is an electricity-driven technology for the microbial reduction of CO 2 to organic commodities. However, the limited solubility of CO 2 in a solution and the inefficient electron transfer make it impossible for microorganisms to obtain an efficient surface for catalytic interaction, thus resulting in the low efficiency of MES. To address this, we introduce a multifunctional perovskite-based cathode material Pr 0.5 (Ba 0.5 Sr 0.5 ) 0.5 Co 0.8 Fe 0.2 O 3-δ -carbon felt (Pr 0.5 BSCF-CF), which provides a simultaneously significant increase in CO 2 absorption and hydrogen production. As a result, the volumetric acetate production rate of MES obtained by Pr 0.5 BSCF-CF is 0.24 ± 0.01 g L -1 day -1 , and it achieves a maximum acetate titer of 13.74 ± 0.20 g L -1 within 70 days. An adequate supply of CO 2 and H 2 also provides a sufficient amount of substrates and energy for the self-replication of the biocatalysts in the MES reactor. This effect not only increases the amount of biocatalysts but also optimizes the functions of the biocatalysts; the above benefits further improve the production efficiency of the MES system. This strategy demonstrates that the development of perovskite-based multifunctional cathodes with a simultaneous supplementation of substrates and electrons is a promising approach toward improving the MES efficiency.

Neda Faraghiparapari, Karsten Zengler

Journal of Chemical Technology & Biotechnology • 2016

Abstract BACKGROUND Microbial electrosynthesis ( MES ), a process by which microorganisms reduce carbon dioxide to multi‐carbon compounds using electrical current as energy source, has so far been demonstrated at temperatures ranging from 25 °C to 37 °C. Elevated operating temperatures, however, could improve overall performance and product recovery. Here the effect of temperature on MES by the acetogenic thermophiles Moorella thermoacetica and Moorella thermoautotrophica is investigated . RESULTS Experiments were performed at operating temperatures ranging from 25 °C to 70 °C to determine the optimum operating temperature for MES . Optimal performance was observed to be close to the optimum growth temperatures reported for these strains. Production rate and activation energy of acetate at 60 °C was 6.9 ± 0.6 mM m −2 d −1 and 45.1 ± 3.8 kJ mol −1 for M. thermoacetica and 11.6 ± 0.9 mM m −2 d −1 and 58.9 ± 2.5 kJ mol −1 for M. thermoautotrophica with columbic efficiencies ( CE ) of 79 ± 15% and 72 ± 4%, respectively. CONCLUSION Considering CE and acetate production rate during MES , M. thermoautotrophica outperformed M. thermoacetica over a wide range of operating temperatures. Current‐dependent reduction of CO 2 also occurred below the minimum growth temperature of these strains, suggesting that MES is non‐growth associated. © 2016 Society of Chemical Industry

Oriol Cabau-Peinado, Marijn Winkelhorst, Rozanne Stroek et al.

Trends in biotechnology • 2024

Carbon-based products are essential to society, yet producing them from fossil fuels is unsustainable. Microorganisms have the ability to take up electrons from solid electrodes and convert carbon dioxide (CO 2 ) to valuable carbon-based chemicals. However, higher productivities and energy efficiencies are needed to reach a viability that can make the technology transformative. Here, we show how a biofilm-based microbial porous cathode in a directed flow-through electrochemical system can continuously reduce CO 2 to even-chain C2-C6 carboxylic acids over 248 days. We demonstrate a threefold higher biofilm concentration, volumetric current density, and productivity compared with the state of the art. Most notably, the volumetric productivity (VP) resembles those achieved in laboratory-scale and industrial syngas (CO-H 2 -CO 2 ) fermentation and chain elongation fermentation. This work highlights key design parameters for efficient electricity-driven microbial CO 2 reduction. There is need and room to improve the rates of electrode colonization and microbe-specific kinetics to scale up the technology.

Sofia Babanova, Kayla Carpenter, Sujal Phadke et al.

Journal of The Electrochemical Society • 2016

This study evaluated the influence of the membrane type on the performance of bioelectromethanogenesis reactors.The functional activities and taxonomic composition of bioelectrochemical systems (BES) with Nafion 117 or Ultrex CMI-7000 membranes were assessed.Functional activity was measured as methane production and current consumption rates throughout operation.Microbial biomass and phylogenetic diversity were characterized at strategic intervals related to the membrane type used.The Nafion-BES reactor showed the best performance in terms of current consumption and methane production in the early operational period and a strong selection for fermentative bacteria.However, the Nafion-BES was not able to sustain this activity over the course of 7 subpassages since methanogenic species were ultimately selected against and did not appear in the community composition for the last two subpassages.In contrast, the Ultrex-BES had a lower pH concentration gradient and lower overall current consumption activity; however, the methane production activity from the Ultrex-BES was equivalent or better than the Nafion-BES reactor and was sustained throughout the seven subpassages.The membrane type appeared to be responsible not only for differences in the electrochemical operation of the BESs but it also influenced microbial taxonomic composition and dynamics.

Weiwei Cai, Wenzong Liu, Bo Wang et al.

Applied and Environmental Microbiology • 2020

Hydrogen-entangled electron transfer has been verified as an important extracellular pathway of sharing reducing equivalents to regulate biofilm activities within a diversely anaerobic environment, especially in microbial electrosynthesis systems. However, with a lack of useful methods for in situ hydrogen detection in cathodic biofilms, the role of hydrogen involvement in electron transfer is still debatable. Here, a cathodic biofilm was constructed in CH 4 -produced microbial electrosynthesis reactors, in which the hydrogen evolution dynamic was analyzed to confirm the presence of hydrogen-associated electron transfer near the cathode within a micrometer scale. Fluorescent in situ hybridization images indicated that a colocalized community of archaea and bacteria developed within a 58.10-μm-thick biofilm at the cathode, suggesting that the hydrogen gradient detected by the microsensor was consumed by the collaboration of bacteria and archaea. Coupling of a microsensor and cyclic voltammetry test further provided semiquantitative results of the hydrogen-associated contribution to methane generation (around 21.20% ± 1.57% at a potential of -0.5 V to -0.69 V). This finding provides deep insight into the mechanism of electron transfer in biofilm on conductive materials. IMPORTANCE Electron transfer from an electrode to biofilm is of great interest to the fields of microbial electrochemical technology, bioremediation, and methanogenesis. It has a promising potential application to boost more value-added products or pollutant degradation. Importantly, the ability of microbes to obtain electrons from electrodes and utilize them brings new insight into direct interspecies electron transfer during methanogenesis. Previous studies verified the direct pathway of electron transfer from the electrode to a pure-culture bacterium, but it was rarely reported how the methanogenic biofilm of mixed cultures shares electrons by a hydrogen-associated or hydrogen-free pathway. In the current study, a combination method of microsensor and cyclic voltammetry successfully semiquantified the role of hydrogen in electron transfer from an electrode to methanogenic biofilm.

Hui Wang, Hongxia Du, Shufang Zeng et al.

Bioelectrochemistry • 2021

Abraham Gomez Vidales, Guillaume Bruant, Sasha Omanovic et al.

Electrochimica Acta • 2021