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A variety of hydrogenotrophic enrichment cultures catalyse cathodic reactions. Sci Rep 2019; 9:2356. [PMID: 30787309 PMCID: PMC6382808 DOI: 10.1038/s41598-018-38006-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 12/18/2018] [Indexed: 12/03/2022] Open
Abstract
Biocathodes where living microorganisms catalyse reduction of CO2 can potentially be used to produce valuable chemicals. Microorganisms harbouring hydrogenases may play a key role for biocathode performance since H2 generated on the electrode surface can act as an electron donor for CO2 reduction. In this study, the possibility of catalysing cathodic reactions by hydrogenotrophic methanogens, acetogens, sulfate-reducers, denitrifiers, and acetotrophic methanogens was investigated. The cultures were enriched from an activated sludge inoculum and performed the expected metabolic functions. All enrichments formed distinct microbial communities depending on their electron donor and electron acceptor. When the cultures were added to an electrochemical cell, linear sweep voltammograms showed a shift in current generation close to the hydrogen evolution potential (−1 V versus SHE) with higher cathodic current produced at a more positive potential. All enrichment cultures except the denitrifiers were also used to inoculate biocathodes of microbial electrolysis cells operated with H+ and bicarbonate as electron acceptors and this resulted in current densities between 0.1–1 A/m2. The microbial community composition of biocathodes inoculated with different enrichment cultures were as different from each other as they were different from their suspended culture inoculum. It was noteworthy that Methanobacterium sp. appeared on all the biocathodes suggesting that it is a key microorganism catalysing biocathode reactions.
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Abstract
Microbial electrosynthesis (MES) is a process where bacteria acquire electrons from a cathode to convert CO2 into multicarbon compounds or methane. In MES with Sporomusa ovata as the microbial catalyst, cathode potential has often been used as a benchmark to determine whether electron uptake is hydrogen-dependent. In this study, H2 was detected by a microsensor in proximity to the cathode. With a sterile fresh medium, H2 was produced at a potential of −700 mV versus Ag/AgCl, whereas H2 was detected at −500 mV versus Ag/AgCl with cell-free spent medium from a S. ovata culture. Furthermore, H2 evolution rates were increased with potentials lower than −500 mV in the presence of cell-free spent medium in the cathode chamber. Nickel and cobalt were detected at the cathode surface after exposure to the spent medium, suggesting a possible participation of these catalytic metals in the observed faster hydrogen evolution. The results presented here show that S. ovata-induced alterations of the cathodic electrolytes of a MES reactor reduced the electrical energy required for hydrogen evolution. These observations also indicated that, even at higher cathode potentials, at least a part of the electrons coming from the electrode are transferred to S. ovata via H2 during MES.
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53
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Jiang Y, Jianxiong Zeng R. Expanding the product spectrum of value added chemicals in microbial electrosynthesis through integrated process design-A review. BIORESOURCE TECHNOLOGY 2018; 269:503-512. [PMID: 30174268 DOI: 10.1016/j.biortech.2018.08.101] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 08/23/2018] [Accepted: 08/24/2018] [Indexed: 06/08/2023]
Abstract
Microbial electrosynthesis (MES) is a novel microbial electrochemical technology proposed for chemicals production with the storage of sustainable energy. However, the practical application of MES is currently restricted by the limited low market value of products in one-step conversion process, mostly acetate. A theme that is pervasive throughout this review is the challenges associated with the expanded product spectrum. Several recent research efforts to improve acetate production, using novel reactor configuration, renewable power supply, and various 3-D cathode are summarized. The importance of genetic modification, two-step hybrid process, as well as input substrates other than CO2 are highlighted in this review as the future research paths for higher value chemicals production. At last, how to integrate MES with existing biochemicals processes is proposed. Definitely, more studies are encouraged to evaluate the overall performances and economic efficiency of these integrated process designs to make MES more competitive.
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Affiliation(s)
- Yong Jiang
- Center of Wastewater Resource Recovery, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Raymond Jianxiong Zeng
- Center of Wastewater Resource Recovery, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China.
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Philips J, Monballyu E, Georg S, De Paepe K, Prévoteau A, Rabaey K, Arends JBA. AnAcetobacteriumstrain isolated with metallic iron as electron donor enhances iron corrosion by a similar mechanism asSporomusa sphaeroides. FEMS Microbiol Ecol 2018; 95:5184449. [DOI: 10.1093/femsec/fiy222] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 11/14/2018] [Indexed: 02/02/2023] Open
Affiliation(s)
- Jo Philips
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, Ghent 9000, Belgium
| | - Eva Monballyu
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, Ghent 9000, Belgium
| | - Steffen Georg
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, Ghent 9000, Belgium
| | - Kim De Paepe
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, Ghent 9000, Belgium
| | - Antonin Prévoteau
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, Ghent 9000, Belgium
| | - Korneel Rabaey
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, Ghent 9000, Belgium
| | - Jan B A Arends
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, Ghent 9000, Belgium
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55
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Del Pilar Anzola Rojas M, Zaiat M, Gonzalez ER, De Wever H, Pant D. Effect of the electric supply interruption on a microbial electrosynthesis system converting inorganic carbon into acetate. BIORESOURCE TECHNOLOGY 2018; 266:203-210. [PMID: 29982040 DOI: 10.1016/j.biortech.2018.06.074] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 06/21/2018] [Accepted: 06/22/2018] [Indexed: 06/08/2023]
Abstract
Microbial electrosynthesis (MES) technology relies on the direct use of electrons to convert CO2 into long chain organic chemicals. Therefore, MES has been proposed to be coupled to the renewable electricity supply, mainly from solar and wind sources. However, those energies suffer fluctuations and interruptions of variable duration, which can have an adverse effect on MES performance. Such effects on MES has been evaluated for the first time under different interruptions time. H-cell-MES reactors were disconnected from power supply during 4, 6, 8, 16, 32 and 64 h. Interruptions affected the acetate production rate, causing a decrease of until 77% after 64 h off. However, after all the interruptions, the acetate production was restored, taking between 7 and 16 h for the reduction current to turn steady. Therefore, microbial community on MES proved to be resilient and able to recover the electro-autotrophic activity despite the duration of current supply interruptions.
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Affiliation(s)
- Mélida Del Pilar Anzola Rojas
- Separation and Conversion Technology, Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol, Belgium; São Carlos Institute of Chemistry, University of São Paulo (USP), Brazil
| | - Marcelo Zaiat
- Laboratory of Biological Processes, Center for Research, Development and Innovation in Environmental Engineering, São Carlos School of Engineering, University of São Paulo (USP), Brazil
| | | | - Heleen De Wever
- Separation and Conversion Technology, Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol, Belgium
| | - Deepak Pant
- Separation and Conversion Technology, Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol, Belgium.
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56
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Zou L, Qiao Y, Li CM. Boosting Microbial Electrocatalytic Kinetics for High Power Density: Insights into Synthetic Biology and Advanced Nanoscience. ELECTROCHEM ENERGY R 2018. [DOI: 10.1007/s41918-018-0020-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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57
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Katuri KP, Kalathil S, Ragab A, Bian B, Alqahtani MF, Pant D, Saikaly PE. Dual-Function Electrocatalytic and Macroporous Hollow-Fiber Cathode for Converting Waste Streams to Valuable Resources Using Microbial Electrochemical Systems. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1707072. [PMID: 29707854 DOI: 10.1002/adma.201707072] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Indexed: 06/08/2023]
Abstract
Dual-function electrocatalytic and macroporous hollow-fiber cathodes are recently proposed as promising advanced material for maximizing the conversion of waste streams such as wastewater and waste CO2 to valuable resources (e.g., clean freshwater, energy, value-added chemicals) in microbial electrochemical systems. The first part of this progress report reviews recent developments in this type of cathode architecture for the simultaneous recovery of clean freshwater and energy from wastewater. Critical insights are provided on suitable materials for fabricating these cathodes, as well as addressing some challenges in the fabrication process with proposed strategies to overcome them. The second and complementary part of the progress report highlights how the unique features of this cathode architecture can solve one of the intrinsic bottlenecks (gas-liquid mass transfer limitation) in the application of microbial electrochemical systems for CO2 reduction to value-added products. Strategies to further improve the availability of CO2 to microbial catalysts on the cathode are proposed. The importance of understanding microbe-cathode interactions, as well as electron transfer mechanisms at the cathode-cell and cell-cell interface to better design dual-function macroporous hollow-fiber cathodes, is critically discussed with insights on how the choice of material is important in facilitating direct electron transfer versus mediated electron transfer.
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Affiliation(s)
- Krishna P Katuri
- Biological and Environmental Sciences and Engineering (BESE) Division, Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Shafeer Kalathil
- Biological and Environmental Sciences and Engineering (BESE) Division, Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Ala'a Ragab
- Biological and Environmental Sciences and Engineering (BESE) Division, Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Bin Bian
- Biological and Environmental Sciences and Engineering (BESE) Division, Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Manal F Alqahtani
- Biological and Environmental Sciences and Engineering (BESE) Division, Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Deepak Pant
- Separation and Conversion Technology, Flemish Institute for Technological Research (VITO), Boeretang 200, Mol, 2400, Belgium
| | - Pascal E Saikaly
- Biological and Environmental Sciences and Engineering (BESE) Division, Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
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58
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Optimization of the chemolithoautotrophic biofilm growth of Cupriavidus necator by means of electrochemical hydrogen synthesis. CHEMICAL PAPERS 2018. [DOI: 10.1007/s11696-018-0382-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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59
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Yun H, Liang B, Kong D, Wang A. Improving biocathode community multifunctionality by polarity inversion for simultaneous bioelectroreduction processes in domestic wastewater. CHEMOSPHERE 2018; 194:553-561. [PMID: 29241129 DOI: 10.1016/j.chemosphere.2017.12.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 12/05/2017] [Accepted: 12/06/2017] [Indexed: 06/07/2023]
Abstract
Bioelectrochemical systems (BESs) have been tentatively applied for wastewater treatment processes, but the complex composition of wastewater could lead to difficulties in establishing functional biofilm or result in performance instability. Few studies have investigated the enrichment of biocathode with domestic wastewater (DW) and the function. A biocathode with multi-pollutant removal capabilities was enriched based on polarity inverted bioanode, which was established with DW. The biocathode function was examined using model pollutants (nitrate, nitrobenzene and Acid Orange 7) supplemented as sole or mixed electron acceptors. When compared to the anaerobic control treatment, the biofilm demonstrated significantly enhanced reduction abilities in the open circuit. For the closed circuit, their removal efficiencies were further enhanced for both the sole and mixed substrates conditions. The bioanodes community structure and diversity markedly changed after operating for 50 d as biocathodes. The biocathode multifunctionality and stability could be related to the maintenance of organic matters fermentative bacteria (mainly belonging to Bacteroidetes, Firmicutes and Synergistetes) and the enrichment of versatile pollutant-reducing bacteria (e.g. Pseudomonas, Thauera and Comamonas from Proteobacteria). Other pollutants, such as perchlorate, sulfate, heavy metals, and halogenated organics, may also work as potential electron acceptors. This study provides a new strategy to improve the biocathode community multifunctionality for simultaneous bioelectroreduction, which can be combined with other wastewater treatment processes in actual application.
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Affiliation(s)
- Hui Yun
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, China
| | - Bin Liang
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
| | - Deyong Kong
- Shenyang Academy of Environmental Sciences, Shenyang, 110167, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Aijie Wang
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China.
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60
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Balancing cellular redox metabolism in microbial electrosynthesis and electro fermentation - A chance for metabolic engineering. Metab Eng 2017; 45:109-120. [PMID: 29229581 DOI: 10.1016/j.ymben.2017.12.003] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 09/15/2017] [Accepted: 12/06/2017] [Indexed: 01/05/2023]
Abstract
More and more microbes are discovered that are capable of extracellular electron transfer, a process in which they use external electrodes as electron donors or acceptors for metabolic reactions. This feature can be used to overcome cellular redox limitations and thus optimizing microbial production. The technologies, termed microbial electrosynthesis and electro-fermentation, have the potential to open novel bio-electro production platforms from sustainable energy and carbon sources. However, the performance of reported systems is currently limited by low electron transport rates between microbes and electrodes and our limited ability for targeted engineering of these systems due to remaining knowledge gaps about the underlying fundamental processes. Metabolic engineering offers many opportunities to optimize these processes, for instance by genetic engineering of pathways for electron transfer on the one hand and target product synthesis on the other hand. With this review, we summarize the status quo of knowledge and engineering attempts around chemical production in bio-electrochemical systems from a microbe perspective. Challenges associated with the introduction or enhancement of extracellular electron transfer capabilities into production hosts versus the engineering of target compound synthesis pathways in natural exoelectrogens are discussed. Recent advances of the research community in both directions are examined critically. Further, systems biology approaches, for instance using metabolic modelling, are examined for their potential to provide insight into fundamental processes and to identify targets for metabolic engineering.
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61
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Baek G, Kim J, Lee S, Lee C. Development of biocathode during repeated cycles of bioelectrochemical conversion of carbon dioxide to methane. BIORESOURCE TECHNOLOGY 2017; 241:1201-1207. [PMID: 28688737 DOI: 10.1016/j.biortech.2017.06.125] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Revised: 06/18/2017] [Accepted: 06/22/2017] [Indexed: 06/07/2023]
Abstract
Functioning biocathodes are essential for electromethanogenesis. This study investigated the development of a biocathode from non-acclimated anaerobic sludge in an electromethanogenesis cell at a cathode potential of -0.7V (vs. standard hydrogen electrode) over four cycles of repeated batch operations. The CO2-to-CH4 conversion rate increased (to 97.7%) while the length of the lag phase decreased as the number of cycles increased, suggesting that a functioning biocathode developed during the repeated subculturing cycles. CO2-resupply test results suggested that the biocathode catalyzed the formation of CH4 via both direct and indirect (H2-mediated) electron transfer mechanisms. The biocathode archaeal community was dominated by the genus Methanobacterium, and most archaeal sequences (>89%) were affiliated with Methanobacterium palustre. The bacterial community was dominated by putative electroactive bacteria, with Arcobacter, which is rarely observed in biocathodes, forming the largest population. These electroactive bacteria were likely involved in electron transfer between the cathode and the methanogens.
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Affiliation(s)
- Gahyun Baek
- School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Eonyang-eup, Ulju-gun, Ulsan 44919, Republic of Korea
| | - Jinsu Kim
- School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Eonyang-eup, Ulju-gun, Ulsan 44919, Republic of Korea
| | - Seungyong Lee
- R&D Center, POSCO E&C Co., Ltd., 241 Incheon Tower-daero, Yeonsu-gu, Incheon 22009, Republic of Korea
| | - Changsoo Lee
- School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Eonyang-eup, Ulju-gun, Ulsan 44919, Republic of Korea.
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62
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63
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Metabolic Reconstruction and Modeling Microbial Electrosynthesis. Sci Rep 2017; 7:8391. [PMID: 28827682 PMCID: PMC5566340 DOI: 10.1038/s41598-017-08877-z] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 07/19/2017] [Indexed: 12/31/2022] Open
Abstract
Microbial electrosynthesis is a renewable energy and chemical production platform that relies on microbial cells to capture electrons from a cathode and fix carbon. Yet despite the promise of this technology, the metabolic capacity of the microbes that inhabit the electrode surface and catalyze electron transfer in these systems remains largely unknown. We assembled thirteen draft genomes from a microbial electrosynthesis system producing primarily acetate from carbon dioxide, and their transcriptional activity was mapped to genomes from cells on the electrode surface and in the supernatant. This allowed us to create a metabolic model of the predominant community members belonging to Acetobacterium, Sulfurospirillum, and Desulfovibrio. According to the model, the Acetobacterium was the primary carbon fixer, and a keystone member of the community. Transcripts of soluble hydrogenases and ferredoxins from Acetobacterium and hydrogenases, formate dehydrogenase, and cytochromes of Desulfovibrio were found in high abundance near the electrode surface. Cytochrome c oxidases of facultative members of the community were highly expressed in the supernatant despite completely sealed reactors and constant flushing with anaerobic gases. These molecular discoveries and metabolic modeling now serve as a foundation for future examination and development of electrosynthetic microbial communities.
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64
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Igarashi K, Kato S. Extracellular electron transfer in acetogenic bacteria and its application for conversion of carbon dioxide into organic compounds. Appl Microbiol Biotechnol 2017; 101:6301-6307. [PMID: 28748358 DOI: 10.1007/s00253-017-8421-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 07/04/2017] [Accepted: 07/04/2017] [Indexed: 11/26/2022]
Abstract
Acetogenic bacteria (i.e., acetogens) produce acetate from CO2 during anaerobic chemoautotrophic growth. Because acetogens fix CO2 with high energy efficiency, they have been investigated as biocatalysts of CO2 conversion into valuable chemicals. Recent studies revealed that some acetogens are capable of extracellular electron transfer (EET), which enables electron exchange between microbial cells and extracellular solid materials. Thus, acetogens are promising candidates as biocatalysts in recently developed bioelectrochemical technologies, including microbial electrosynthesis (MES), in which useful chemicals are biologically produced from CO2 using electricity as the energy source. In microbial photoelectrosynthesis, a variant of MES technology, the conversion of CO2 into organic compounds is achieved using light as the sole energy source without an external power supply. In this mini-review, we introduce the general features of bioproduction and EET of acetogens and describe recent progress and future prospects of MES technologies based on the EET capability of acetogens.
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Affiliation(s)
- Kensuke Igarashi
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo, Hokkaido, 062-8517, Japan
| | - Souichiro Kato
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo, Hokkaido, 062-8517, Japan.
- Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita-9 Nishi-9, Kita-ku, Sapporo, Hokkaido, 060-8589, Japan.
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65
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Pozo G, Lu Y, Pongy S, Keller J, Ledezma P, Freguia S. Selective cathodic microbial biofilm retention allows a high current-to-sulfide efficiency in sulfate-reducing microbial electrolysis cells. Bioelectrochemistry 2017; 118:62-69. [PMID: 28719849 DOI: 10.1016/j.bioelechem.2017.07.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 07/03/2017] [Accepted: 07/10/2017] [Indexed: 12/17/2022]
Abstract
Selective microbial retention is of paramount importance for the long-term performance of cathodic sulfate reduction in microbial electrolysis cells (MECs) due to the slow growth rate of autotrophic sulfate-reducing bacteria. In this work, we investigate the biofilm retention and current-to-sulfide conversion efficiency using carbon granules (CG) or multi-wall carbon nanotubes deposited on reticulated vitreous carbon (MWCNT-RVC) as electrode materials. For ~2months, the MECs were operated at sulfate loading rates of 21 to 309gSO4 -S/m2/d. Although MWCNT-RVC achieved a current density of 57±11A/m2, greater than the 32±9A/m2 observed using CG, both materials exhibited similar sulfate reduction rates (SRR), with MWCNT-RVC reaching 104±16gSO4 -S/m2/d while 110±13gSO4 -S/m2/d were achieved with CG. Pyrosequencing analysis of the 16S rRNA at the end of experimentation revealed a core community dominated by Desulfovibrio (28%), Methanobacterium (19%) and Desulfomicrobium (14%), on the MWCNT-RVC electrodes. While a similar Desulfovibrio relative abundance of 29% was found in CG-biofilms, Desulfomicrobium was found to be significantly less abundant (4%) and Methanobacterium practically absent (0.2%) on CG electrodes. Surprisingly, our results show that CG can achieve higher current-to-sulfide efficiencies at lower power consumption than the nano-modified three-dimensional MWCNT-RVC.
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Affiliation(s)
- Guillermo Pozo
- Advanced Water Management Centre, the University of Queensland, St Lucia, QLD 4072, Australia.
| | - Yang Lu
- Advanced Water Management Centre, the University of Queensland, St Lucia, QLD 4072, Australia
| | - Sebastien Pongy
- Advanced Water Management Centre, the University of Queensland, St Lucia, QLD 4072, Australia; Département Génie Energétique et Environnement, INSA Lyon, 69621 Villeurbanne Cedex, France
| | - Jürg Keller
- Advanced Water Management Centre, the University of Queensland, St Lucia, QLD 4072, Australia
| | - Pablo Ledezma
- Advanced Water Management Centre, the University of Queensland, St Lucia, QLD 4072, Australia
| | - Stefano Freguia
- Advanced Water Management Centre, the University of Queensland, St Lucia, QLD 4072, Australia
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66
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Continuous long-term electricity-driven bioproduction of carboxylates and isopropanol from CO 2 with a mixed microbial community. J CO2 UTIL 2017. [DOI: 10.1016/j.jcou.2017.04.014] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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67
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Aryal N, Tremblay PL, Lizak DM, Zhang T. Performance of different Sporomusa species for the microbial electrosynthesis of acetate from carbon dioxide. BIORESOURCE TECHNOLOGY 2017; 233:184-190. [PMID: 28279911 DOI: 10.1016/j.biortech.2017.02.128] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2017] [Revised: 02/24/2017] [Accepted: 02/25/2017] [Indexed: 05/19/2023]
Abstract
Sporomusa ovata DSM-2662 produces high rate of acetate during microbial electrosynthesis (MES) by reducing CO2 with electrons coming from a cathode. Here, we investigated other Sporomusa for MES with cathode potential set at -690mVvsSHE to establish if this capacity is conserved among this genus and to identify more performant strains. S. ovata DSM-2663 produced acetate 1.8-fold faster than S. ovata DSM-2662. On the contrary, S. ovata DSM-3300 was 2.7-fold slower whereas Sporomusa aerivorans had no MES activity. These results indicate that MES performance varies among Sporomusa. During MES, electron transfer from cathode to microbes often occurs via H2. To establish if efficient coupling between H2 oxidation and CO2 reduction may explain why specific acetogens are more productive MES catalysts, the metabolisms of the investigated Sporomusa were characterized under H2:CO2. Results suggest that other phenotypic traits besides the capacity to oxidize H2 efficiently are involved.
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Affiliation(s)
- Nabin Aryal
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Pier-Luc Tremblay
- School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, PR China
| | - Dawid M Lizak
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Tian Zhang
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby, Denmark; School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, PR China.
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68
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Gildemyn S, Rozendal RA, Rabaey K. A Gibbs Free Energy-Based Assessment of Microbial Electrocatalysis. Trends Biotechnol 2017; 35:393-406. [DOI: 10.1016/j.tibtech.2017.02.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 02/01/2017] [Accepted: 02/03/2017] [Indexed: 10/19/2022]
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69
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Tremblay PL, Angenent LT, Zhang T. Extracellular Electron Uptake: Among Autotrophs and Mediated by Surfaces. Trends Biotechnol 2017; 35:360-371. [DOI: 10.1016/j.tibtech.2016.10.004] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 10/09/2016] [Accepted: 10/10/2016] [Indexed: 11/26/2022]
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70
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Puig S, Ganigué R, Batlle-Vilanova P, Balaguer MD, Bañeras L, Colprim J. Tracking bio-hydrogen-mediated production of commodity chemicals from carbon dioxide and renewable electricity. BIORESOURCE TECHNOLOGY 2017; 228:201-209. [PMID: 28063363 DOI: 10.1016/j.biortech.2016.12.035] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 12/08/2016] [Accepted: 12/09/2016] [Indexed: 05/28/2023]
Abstract
This study reveals that reduction of carbon dioxide (CO2) to commodity chemicals can be functionally compartmentalized in bioelectrochemical systems. In the present example, a syntrophic consortium composed by H2-producers (Rhodobacter sp.) in the biofilm is combined with carboxidotrophic Clostridium species, mainly found in the bulk liquid. The performance of these H2-mediated electricity-driven systems could be tracked by the activity of a biological H2 sensory protein identified at cathode potentials between -0.2V and -0.3V vs SHE. This seems to point out that such signal is not strain specific, but could be detected in any organism containing hydrogenases. Thus, the findings of this work open the door to the development of a biosensor application or soft sensors for monitoring such systems.
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Affiliation(s)
- Sebastià Puig
- LEQUIA, Institute of the Environment, University of Girona, Campus de Montilivi, Carrer Maria Aurèlia Capmany, 69, E-17003 Girona, Catalonia, Spain.
| | - Ramon Ganigué
- LEQUIA, Institute of the Environment, University of Girona, Campus de Montilivi, Carrer Maria Aurèlia Capmany, 69, E-17003 Girona, Catalonia, Spain; Centre of Microbial Ecology and Technology, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
| | - Pau Batlle-Vilanova
- LEQUIA, Institute of the Environment, University of Girona, Campus de Montilivi, Carrer Maria Aurèlia Capmany, 69, E-17003 Girona, Catalonia, Spain; Department of Innovation and Technology, FCC Aqualia, Balmes Street, 36, 6th Floor, 08007 Barcelona, Spain
| | - M Dolors Balaguer
- LEQUIA, Institute of the Environment, University of Girona, Campus de Montilivi, Carrer Maria Aurèlia Capmany, 69, E-17003 Girona, Catalonia, Spain
| | - Lluís Bañeras
- Molecular Microbial Ecology Group, Institute of Aquatic Ecology, University of Girona, E-17071 Girona, Spain
| | - Jesús Colprim
- LEQUIA, Institute of the Environment, University of Girona, Campus de Montilivi, Carrer Maria Aurèlia Capmany, 69, E-17003 Girona, Catalonia, Spain
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71
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Long-term operation of microbial electrosynthesis cell reducing CO2 to multi-carbon chemicals with a mixed culture avoiding methanogenesis. Bioelectrochemistry 2017; 113:26-34. [DOI: 10.1016/j.bioelechem.2016.09.001] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 09/01/2016] [Accepted: 09/01/2016] [Indexed: 11/24/2022]
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72
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Competition between Methanogens and Acetogens in Biocathodes: A Comparison between Potentiostatic and Galvanostatic Control. Int J Mol Sci 2017; 18:ijms18010204. [PMID: 28106846 PMCID: PMC5297834 DOI: 10.3390/ijms18010204] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 12/02/2016] [Accepted: 01/14/2017] [Indexed: 01/15/2023] Open
Abstract
Microbial electrosynthesis is a useful form of technology for the renewable production of organic commodities from biologically catalyzed reduction of CO2. However, for the technology to become applicable, process selectivity, stability and efficiency need strong improvement. Here we report on the effect of different electrochemical control modes (potentiostatic/galvanostatic) on both the start-up characteristics and steady-state performance of biocathodes using a non-enriched mixed-culture inoculum. Based on our results, it seems that kinetic differences exist between the two dominant functional microbial groups (i.e., homoacetogens and methanogens) and that by applying different current densities, these differences may be exploited to steer product selectivity and reactor performance.
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73
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Microbial bioelectrosynthesis of hydrogen: Current challenges and scale-up. Enzyme Microb Technol 2017; 96:1-13. [DOI: 10.1016/j.enzmictec.2016.09.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 08/31/2016] [Accepted: 09/08/2016] [Indexed: 12/18/2022]
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74
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Mixed Culture Biocathodes for Production of Hydrogen, Methane, and Carboxylates. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2017; 167:203-229. [DOI: 10.1007/10_2017_15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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75
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Zhang T, Tremblay PL. Hybrid photosynthesis-powering biocatalysts with solar energy captured by inorganic devices. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:249. [PMID: 29093753 PMCID: PMC5663055 DOI: 10.1186/s13068-017-0943-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 10/24/2017] [Indexed: 05/03/2023]
Abstract
The biological reduction of CO2 driven by sunlight via photosynthesis is a crucial process for life on earth. However, the conversion efficiency of solar energy to biomass by natural photosynthesis is low. This translates in bioproduction processes relying on natural photosynthesis that are inefficient energetically. Recently, hybrid photosynthetic technologies with the potential of significantly increasing the efficiency of solar energy conversion to products have been developed. In these systems, the reduction of CO2 into biofuels or other chemicals of interest by biocatalysts is driven by solar energy captured with inorganic devices such as photovoltaic cells or photoelectrodes. Here, we explore hybrid photosynthesis and examine the strategies being deployed to improve this biotechnology.
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Affiliation(s)
- Tian Zhang
- School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan, 430070 People’s Republic of China
| | - Pier-Luc Tremblay
- School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan, 430070 People’s Republic of China
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76
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Raes SMT, Jourdin L, Buisman CJN, Strik DPBTB. Continuous Long-Term Bioelectrochemical Chain Elongation to Butyrate. ChemElectroChem 2016. [DOI: 10.1002/celc.201600587] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Sanne M. T. Raes
- Sub-department of Environmental Technology; Wageningen University & Research; Axis- Z, Bornse Weilanden 9 6708 WG Wageningen The Netherlands
| | - Ludovic Jourdin
- Sub-department of Environmental Technology; Wageningen University & Research; Axis- Z, Bornse Weilanden 9 6708 WG Wageningen The Netherlands
| | - Cees J. N. Buisman
- Sub-department of Environmental Technology; Wageningen University & Research; Axis- Z, Bornse Weilanden 9 6708 WG Wageningen The Netherlands
| | - David P. B. T. B. Strik
- Sub-department of Environmental Technology; Wageningen University & Research; Axis- Z, Bornse Weilanden 9 6708 WG Wageningen The Netherlands
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77
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Butler CS, Lovley DR. How to Sustainably Feed a Microbe: Strategies for Biological Production of Carbon-Based Commodities with Renewable Electricity. Front Microbiol 2016; 7:1879. [PMID: 27965629 PMCID: PMC5124563 DOI: 10.3389/fmicb.2016.01879] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 11/08/2016] [Indexed: 11/15/2022] Open
Abstract
As interest and application of renewable energy grows, strategies are needed to align the asynchronous supply and demand. Microbial metabolisms are a potentially sustainable mechanism for transforming renewable electrical energy into biocommodities that are easily stored and transported. Acetogens and methanogens can reduce carbon dioxide to organic products including methane, acetic acid, and ethanol. The library of biocommodities is expanded when engineered metabolisms of acetogens are included. Typically, electrochemical systems are employed to integrate renewable energy sources with biological systems for production of carbon-based commodities. Within these systems, there are three prevailing mechanisms for delivering electrons to microorganisms for the conversion of carbon dioxide to reduce organic compounds: (1) electrons can be delivered to microorganisms via H2 produced separately in a electrolyzer, (2) H2 produced at a cathode can convey electrons to microorganisms supported on the cathode surface, and (3) a cathode can directly feed electrons to microorganisms. Each of these strategies has advantages and disadvantages that must be considered in designing full-scale processes. This review considers the evolving understanding of each of these approaches and the state of design for advancing these strategies toward viability.
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Affiliation(s)
- Caitlyn S Butler
- Civil and Environmental Engineering, University of Massachusetts Amherst, MA, USA
| | - Derek R Lovley
- Microbiology, University of Massachusetts Amherst, MA, USA
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78
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Bajracharya S, Vanbroekhoven K, Buisman CJN, Pant D, Strik DPBTB. Application of gas diffusion biocathode in microbial electrosynthesis from carbon dioxide. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:22292-22308. [PMID: 27436381 DOI: 10.1007/s11356-016-7196-x] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 07/06/2016] [Indexed: 05/19/2023]
Abstract
Microbial catalysis of carbon dioxide (CO2) reduction to multi-carbon compounds at the cathode is a highly attractive application of microbial electrosynthesis (MES). The microbes reduce CO2 by either taking the electrons or reducing the equivalents produced at the cathode. While using gaseous CO2 as the carbon source, the biological reduction process depends on the dissolution and mass transfer of CO2 in the electrolyte. In order to deal with this issue, a gas diffusion electrode (GDE) was investigated by feeding CO2 through the GDE into the MES reactor for its reduction at the biocathode. A combination of the catalyst layer (porous activated carbon and Teflon binder) and the hydrophobic gas diffusion layer (GDL) creates a three-phase interface at the electrode. So, CO2 and reducing equivalents will be available to the biocatalyst on the cathode surface. An enriched inoculum consisting of acetogenic bacteria, prepared from an anaerobic sludge, was used as a biocatalyst. The cathode potential was maintained at -1.1 V vs Ag/AgCl to facilitate direct and/or hydrogen-mediated CO2 reduction. Bioelectrochemical CO2 reduction mainly produced acetate but also extended the products to ethanol and butyrate. Average acetate production rates of 32 and 61 mg/L/day, respectively, with 20 and 80 % CO2 gas mixture feed were achieved with 10 cm2 of GDE. The maximum acetate production rate remained 238 mg/L/day for 20 % CO2 gas mixture. In conclusion, a gas diffusion biocathode supported bioelectrochemical CO2 reduction with enhanced mass transfer rate at continuous supply of gaseous CO2. Graphical abstract ᅟ.
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Affiliation(s)
- Suman Bajracharya
- Separation and Conversion Technologies, Flemish Institute for Technological Research (VITO), Mol, Belgium
- Sub-department of Environmental Technology, Wageningen University, Wageningen, The Netherlands
| | - Karolien Vanbroekhoven
- Separation and Conversion Technologies, Flemish Institute for Technological Research (VITO), Mol, Belgium
| | - Cees J N Buisman
- Sub-department of Environmental Technology, Wageningen University, Wageningen, The Netherlands
| | - Deepak Pant
- Separation and Conversion Technologies, Flemish Institute for Technological Research (VITO), Mol, Belgium.
| | - David P B T B Strik
- Sub-department of Environmental Technology, Wageningen University, Wageningen, The Netherlands
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79
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Pozo G, Jourdin L, Lu Y, Keller J, Ledezma P, Freguia S. Cathodic biofilm activates electrode surface and achieves efficient autotrophic sulfate reduction. Electrochim Acta 2016. [DOI: 10.1016/j.electacta.2016.07.100] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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80
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Jourdin L, Freguia S, Flexer V, Keller J. Bringing High-Rate, CO2-Based Microbial Electrosynthesis Closer to Practical Implementation through Improved Electrode Design and Operating Conditions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:1982-9. [PMID: 26810392 DOI: 10.1021/acs.est.5b04431] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The enhancement of microbial electrosynthesis (MES) of acetate from CO2 to performance levels that could potentially support practical implementations of the technology must go through the optimization of key design and operating conditions. We report that higher proton availability drastically increases the acetate production rate, with pH 5.2 found to be optimal, which will likely suppress methanogenic activity without inhibitor addition. Applied cathode potential as low as -1.1 V versus SHE still achieved 99% of electron recovery in the form of acetate at a current density of around -200 A m(-2). These current densities are leading to an exceptional acetate production rate of up to 1330 g m(-2) day(-1) at pH 6.7. Using highly open macroporous reticulated vitreous carbon electrodes with macropore sizes of about 0.6 mm in diameter was found to be optimal for achieving a good balance between total surface area available for biofilm formation and effective mass transfer between the bulk liquid and the electrode and biofilm surface. Furthermore, we also successfully demonstrated the use of a synthetic biogas mixture as carbon dioxide source, yielding similarly high MES performance as pure CO2. This would allow this process to be used effectively for both biogas quality improvement and conversion of the available CO2 to acetate.
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Affiliation(s)
- Ludovic Jourdin
- Advanced Water Management Centre and ‡Centre for Microbial Electrochemical Systems, The University of Queensland , Gehrmann Building, Brisbane, QLD 4072, Australia
| | - Stefano Freguia
- Advanced Water Management Centre and ‡Centre for Microbial Electrochemical Systems, The University of Queensland , Gehrmann Building, Brisbane, QLD 4072, Australia
| | - Victoria Flexer
- Advanced Water Management Centre and ‡Centre for Microbial Electrochemical Systems, The University of Queensland , Gehrmann Building, Brisbane, QLD 4072, Australia
| | - Jurg Keller
- Advanced Water Management Centre and ‡Centre for Microbial Electrochemical Systems, The University of Queensland , Gehrmann Building, Brisbane, QLD 4072, Australia
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