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Enzmann F, Mayer F, Rother M, Holtmann D. Methanogens: biochemical background and biotechnological applications. AMB Express 2018; 8:1. [PMID: 29302756 PMCID: PMC5754280 DOI: 10.1186/s13568-017-0531-x] [Citation(s) in RCA: 158] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 12/19/2017] [Indexed: 02/05/2023] Open
Abstract
Since fossil sources for fuel and platform chemicals will become limited in the near future, it is important to develop new concepts for energy supply and production of basic reagents for chemical industry. One alternative to crude oil and fossil natural gas could be the biological conversion of CO2 or small organic molecules to methane via methanogenic archaea. This process has been known from biogas plants, but recently, new insights into the methanogenic metabolism, technical optimizations and new technology combinations were gained, which would allow moving beyond the mere conversion of biomass. In biogas plants, steps have been undertaken to increase yield and purity of the biogas, such as addition of hydrogen or metal granulate. Furthermore, the integration of electrodes led to the development of microbial electrosynthesis (MES). The idea behind this technique is to use CO2 and electrical power to generate methane via the microbial metabolism. This review summarizes the biochemical and metabolic background of methanogenesis as well as the latest technical applications of methanogens. As a result, it shall give a sufficient overview over the topic to both, biologists and engineers handling biological or bioelectrochemical methanogenesis.
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Affiliation(s)
- Franziska Enzmann
- DECHEMA Research Institute, Industrial Biotechnology, Theodor-Heuss-Allee 25, 60486 Frankfurt am Main, Germany
| | - Florian Mayer
- DECHEMA Research Institute, Industrial Biotechnology, Theodor-Heuss-Allee 25, 60486 Frankfurt am Main, Germany
| | - Michael Rother
- Technische Universität Dresden, Institut für Mikrobiologie, Zellescher Weg 20b, 01217 Dresden, Germany
| | - Dirk Holtmann
- DECHEMA Research Institute, Industrial Biotechnology, Theodor-Heuss-Allee 25, 60486 Frankfurt am Main, Germany
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52
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Reactors for Microbial Electrobiotechnology. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2018; 167:231-271. [PMID: 29651504 DOI: 10.1007/10_2017_40] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
From the first electromicrobial experiment to a sophisticated microbial electrochemical process - it all takes place in a reactor. Whereas the reactor design and materials used strongly influence the obtained results, there are no common platforms for MES reactors. This is a critical convention gap, as cross-comparison and benchmarking among MES as well as MES vs. conventional biotechnological processes is needed. Only knowledge driven engineering of MES reactors will pave the way to application and commercialization. In this chapter we first assess the requirements on reactors to be used for bioelectrochemical systems as well as potential losses caused by the reactor design. Subsequently, we compile the main types and designs of reactors used for MES so far, starting from simple H-cells to stirred tank reactors. We conclude with a discussion on the weaknesses and strengths of the existing types of reactors for bioelectrochemical systems that are scored on design criteria and draw conclusions for the future engineering of MES reactors.
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53
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Liu SY, Charles W, Ho G, Cord-Ruwisch R, Cheng KY. Bioelectrochemical enhancement of anaerobic digestion: Comparing single- and two-chamber reactor configurations at thermophilic conditions. BIORESOURCE TECHNOLOGY 2017; 245:1168-1175. [PMID: 28863995 DOI: 10.1016/j.biortech.2017.08.095] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 08/14/2017] [Accepted: 08/16/2017] [Indexed: 06/07/2023]
Abstract
Bioelectrochemical system (BES) can act as an auxiliary technology for improving organic waste treatment and biogas production in anaerobic digestion (AD). For the first time this study directly compared the performance of a single- and a cation-exchange membrane-equipped two-chamber BES-AD systems at thermophilic conditions. The results indicated that an active glucose-fed thermophilic anaerobic sludge could readily (<3days) increase biogas production in both reactor configurations by inserting a carbon electrode poised at -0.8V (vs. Ag/AgCl). However, after a 3-week operation, the biogas production rates from the single- and two-chamber BES reactor decreased due to volatile fatty acids accumulation. Only the two-chamber configuration could enable methane enrichment (98% CH4v/v) in biogas. Overall, this study suggests that integrating bioelectrodes in-situ could not sustainably improve biogas production in a thermophilic AD reactor, and future studies should be directed towards the use of bioelectrodes for improving biogas quality.
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Affiliation(s)
- Si Ying Liu
- School of Engineering and Information Technology, Murdoch University, WA 6150, Australia
| | - Wipa Charles
- School of Engineering and Information Technology, Murdoch University, WA 6150, Australia
| | - Goen Ho
- School of Engineering and Information Technology, Murdoch University, WA 6150, Australia
| | - Ralf Cord-Ruwisch
- School of Engineering and Information Technology, Murdoch University, WA 6150, Australia
| | - Ka Yu Cheng
- School of Engineering and Information Technology, Murdoch University, WA 6150, Australia; CSIRO Land and Water, Floreat, WA 6014, Australia.
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54
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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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55
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High-pressure thermophilic electromethanogenic system producing methane at 5 MPa, 55°C. J Biosci Bioeng 2017; 124:327-332. [DOI: 10.1016/j.jbiosc.2017.04.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 04/03/2017] [Indexed: 11/20/2022]
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56
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Draft Genome Sequence of Methanothermobacter sp. Strain EMTCatA1, Reconstructed from the Metagenome of a Thermophilic Electromethanogenesis-Catalyzing Biocathode. GENOME ANNOUNCEMENTS 2017; 5:5/35/e00892-17. [PMID: 28860250 PMCID: PMC5578848 DOI: 10.1128/genomea.00892-17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A draft genome of Methanothermobacter sp. strain EMTCatA1 was reconstructed from a metagenome of a thermophilic electromethanogenic biocathode. This genome will provide information about methanogens catalyzing methanogenesis at the biocathodes.
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57
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Zhen G, Lu X, Kobayashi T, Su L, Kumar G, Bakonyi P, He Y, Sivagurunathan P, Nemestóthy N, Xu K, Zhao Y. Continuous micro-current stimulation to upgrade methanolic wastewater biodegradation and biomethane recovery in an upflow anaerobic sludge blanket (UASB) reactor. CHEMOSPHERE 2017; 180:229-238. [PMID: 28410503 DOI: 10.1016/j.chemosphere.2017.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 03/31/2017] [Accepted: 04/02/2017] [Indexed: 06/07/2023]
Abstract
The dispersion of granules in upflow anaerobic sludge blanket (UASB) reactor represents a critical technical issue in methanolic wastewater treatment. In this study, the potentials of coupling a microbial electrolysis cell (MEC) into an UASB reactor for improving methanolic wastewater biodegradation, long-term process stability and biomethane recovery were evaluated. The results indicated that coupling a MEC system was capable of improving the overall performance of UASB reactor for methanolic wastewater treatment. The combined system maintained the comparatively higher methane yield and COD removal efficiency over the single UASB process through the entire process, with the methane production at the steady-state conditions approaching 1504.7 ± 92.2 mL-CH4 L-1-reactor d-1, around 10.1% higher than the control UASB (i.e. 1366.4 ± 71.0 mL-CH4 L-1-reactor d-1). The further characterizations verified that the input of external power source could stimulate the metabolic activity of microbes and reinforced the EPS secretion. The produced EPS interacted with Fe2+/3+ liberated during anodic corrosion of iron electrode to create a gel-like three-dimensional [-Fe-EPS-]n matrix, which promoted cell-cell cohesion and maintained the structural integrity of granules. Further observations via SEM and FISH analysis demonstrated that the use of bioelectrochemical stimulation promoted the growth and proliferation of microorganisms, which diversified the degradation routes of methanol, convert the wasted CO2 into methane and accordingly increased the process stability and methane productivity.
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Affiliation(s)
- Guangyin Zhen
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Dongchuan Rd. 500, Shanghai, 200241, PR China; Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan.
| | - Xueqin Lu
- Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi, 980-8579, Japan.
| | - Takuro Kobayashi
- Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan
| | - Lianghu Su
- Nanjing Institute of Environmental Sciences of the Ministry of Environmental Protection, 210042, Nanjing, PR China
| | - Gopalakrishnan Kumar
- Department of Environmental Engineering, Daegu University, Jillyang, Gyeongsan, Gyeongbuk, Republic of Korea
| | - Péter Bakonyi
- Research Institute on Bioengineering, Membrane Technology and Energetics, University of Pannonia, Egyetem ut 10, 8200, Veszprém, Hungary
| | - Yan He
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Dongchuan Rd. 500, Shanghai, 200241, PR China
| | - Periyasamy Sivagurunathan
- Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan
| | - Nándor Nemestóthy
- Research Institute on Bioengineering, Membrane Technology and Energetics, University of Pannonia, Egyetem ut 10, 8200, Veszprém, Hungary
| | - Kaiqin Xu
- Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan.
| | - Youcai Zhao
- The State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, 200092, PR China
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58
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Experimental and Mathematical Analyses of Bio-electrochemical Conversion of Carbon Dioxide to Methane. ACTA ACUST UNITED AC 2017. [DOI: 10.1016/j.egypro.2017.03.1857] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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59
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Dykstra CM, Pavlostathis SG. Methanogenic Biocathode Microbial Community Development and the Role of Bacteria. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:5306-5316. [PMID: 28368570 DOI: 10.1021/acs.est.6b04112] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The cathode microbial community of a methanogenic bioelectrochemical system (BES) is key to the efficient conversion of carbon dioxide (CO2) to methane (CH4) with application to biogas upgrading. The objective of this study was to compare the performance and microbial community composition of a biocathode inoculated with a mixed methanogenic (MM) culture to a biocathode inoculated with an enriched hydrogenotrophic methanogenic (EHM) culture, developed from the MM culture following pre-enrichment with H2 and CO2 as the only externally supplied electron donor and carbon source, respectively. Using an adjacent Ag/AgCl reference electrode, biocathode potential was poised at -0.8 V (versus SHE) using a potentiostat, with the bioanode acting as the counter electrode. When normalized to cathode biofilm biomass, the methane production in the MM- and EHM-biocathode was 0.153 ± 0.010 and 0.586 ± 0.029 mmol CH4/mg biomass-day, respectively. This study showed that H2/CO2 pre-enriched inoculum enhanced biocathode CH4 production, although the archaeal communities in both biocathodes converged primarily (86-100%) on a phylotype closely related to Methanobrevibacter arboriphilus. The bacterial community of the MM-biocathode was similar to that of the MM inoculum but was enriched in Spirochaetes and other nonexoelectrogenic, fermentative Bacteria. In contrast, the EHM-biocathode bacterial community was enriched in Proteobacteria, exoelectrogens, and putative producers of electron shuttle mediators. Similar biomass levels were detected in the MM- and EHM-biocathodes. Thus, although the archaeal communities were similar in the two biocathodes, the difference in bacterial community composition was likely responsible for the 3.8-fold larger CH4 production rate observed in the EHM-biocathode. Roles for abundant OTUs identified in the biofilm and inoculum cultures were highlighted on the basis of previous reports.
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Affiliation(s)
- Christy M Dykstra
- School of Civil and Environmental Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - Spyros G Pavlostathis
- School of Civil and Environmental Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
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60
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Blasco-Gómez R, Batlle-Vilanova P, Villano M, Balaguer MD, Colprim J, Puig S. On the Edge of Research and Technological Application: A Critical Review of Electromethanogenesis. Int J Mol Sci 2017; 18:E874. [PMID: 28425974 PMCID: PMC5412455 DOI: 10.3390/ijms18040874] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 03/22/2017] [Accepted: 04/11/2017] [Indexed: 11/24/2022] Open
Abstract
The conversion of electrical current into methane (electromethanogenesis) by microbes represents one of the most promising applications of bioelectrochemical systems (BES). Electromethanogenesis provides a novel approach to waste treatment, carbon dioxide fixation and renewable energy storage into a chemically stable compound, such as methane. This has become an important area of research since it was first described, attracting different research groups worldwide. Basics of the process such as microorganisms involved and main reactions are now much better understood, and recent advances in BES configuration and electrode materials in lab-scale enhance the interest in this technology. However, there are still some gaps that need to be filled to move towards its application. Side reactions or scaling-up issues are clearly among the main challenges that need to be overcome to its further development. This review summarizes the recent advances made in the field of electromethanogenesis to address the main future challenges and opportunities of this novel process. In addition, the present fundamental knowledge is critically reviewed and some insights are provided to identify potential niche applications and help researchers to overcome current technological boundaries.
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Affiliation(s)
- Ramiro Blasco-Gómez
- Laboratory of Chemical and Environmental Engineering (LEQUIA), Institute of the Environment, University of Girona, Campus Montilivi, Carrer Maria Aurèlia Capmany, 69, E-17003 Girona, Spain.
| | - Pau Batlle-Vilanova
- Laboratory of Chemical and Environmental Engineering (LEQUIA), Institute of the Environment, University of Girona, Campus Montilivi, Carrer Maria Aurèlia Capmany, 69, E-17003 Girona, Spain.
- Department of Innovation and Technology, FCC Aqualia, Balmes Street, 36, 6th Floor, 08007 Barcelona, Spain.
| | - Marianna Villano
- Department of Chemistry, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy.
| | - Maria Dolors Balaguer
- Laboratory of Chemical and Environmental Engineering (LEQUIA), Institute of the Environment, University of Girona, Campus Montilivi, Carrer Maria Aurèlia Capmany, 69, E-17003 Girona, Spain.
| | - Jesús Colprim
- Laboratory of Chemical and Environmental Engineering (LEQUIA), Institute of the Environment, University of Girona, Campus Montilivi, Carrer Maria Aurèlia Capmany, 69, E-17003 Girona, Spain.
| | - Sebastià Puig
- Laboratory of Chemical and Environmental Engineering (LEQUIA), Institute of the Environment, University of Girona, Campus Montilivi, Carrer Maria Aurèlia Capmany, 69, E-17003 Girona, Spain.
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61
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Draft Genome Sequence of a Novel Coriobacteriaceae sp. Strain, EMTCatB1, Reconstructed from the Metagenome of a Thermophilic Electromethanogenic Biocathode. GENOME ANNOUNCEMENTS 2017; 5:5/10/e00022-17. [PMID: 28280014 PMCID: PMC5347234 DOI: 10.1128/genomea.00022-17] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A draft genome of Coriobacteriaceae sp. strain EMTCatB1 was determined through taxonomic binning of a metagenome of a thermophilic biocathode actively catalyzing electromethanogenesis. This genome will provide information about the biocathode ecosystem, as well as the natural diversity of the Coriobacteriaceae family.
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62
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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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63
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Dykstra CM, Pavlostathis SG. Evaluation of gas and carbon transport in a methanogenic bioelectrochemical system (BES). Biotechnol Bioeng 2016; 114:961-969. [PMID: 27922181 DOI: 10.1002/bit.26230] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 11/22/2016] [Accepted: 11/27/2016] [Indexed: 02/04/2023]
Abstract
Bioelectrochemical systems (BESs) may be used to upgrade anaerobic digester biogas by directly converting CO2 to CH4 . The objective of this study was to evaluate gas (N2 , CO2 , CH4 , and H2 ) and carbon transport within a methanogenic BES. Four BES configurations were evaluated: abiotic anode with abiotic cathode (AAn-ACa), bioanode with abiotic cathode (BAn-ACa), abiotic anode with biocathode (AAn-BCa), and bioanode with biocathode (BAn-BCa). Transport of N2 , a gas commonly used for flushing anoxic systems, out of the anode headspace ranged from 3.7 to 6.2 L/d-atm-m2 , normalized to the proton exchange membrane (PEM) surface area and net driving pressure (NDP). CO2 was transported from the cathode to the anode headspace at rates from 3.7 to 5.4 L/d-atm-m2 . The flux of H2 from cathode to anode headspace was 48% greater when the system had a biocathode (AAn-BCa) than when H2 was produced at an abiotic cathode (BAn-ACa), even though the abiotic cathode headspace had 75% more H2 than the AAn-BCa biocathode at the end of 1 day. A 7-day carbon balance of a batch-fed BAn-BCa BES showed transient microbial carbon storage and a net transport of carbon from anode to cathode. After a 7-day batch incubation, the CH4 production in the biocathode was 27% greater on a molar basis than the initial CO2 supplied to the biocathode headspace, indicating conversion of CO2 produced in the anode. This research expands the current understanding of methanogenic BES operation, which may be used in improving the assessment of BES performance and/or in the development of alternative BES designs and mathematical models. Biotechnol. Bioeng. 2017;114: 961-969. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Christy M Dykstra
- School of Civil and Environmental Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia, 30332-0512
| | - Spyros G Pavlostathis
- School of Civil and Environmental Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia, 30332-0512
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64
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Bioelectrochemical Power-to-Gas: State of the Art and Future Perspectives. Trends Biotechnol 2016; 34:879-894. [DOI: 10.1016/j.tibtech.2016.08.010] [Citation(s) in RCA: 144] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 08/23/2016] [Accepted: 08/25/2016] [Indexed: 12/17/2022]
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65
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Zhang J, Lu Y. Conductive Fe3O4 Nanoparticles Accelerate Syntrophic Methane Production from Butyrate Oxidation in Two Different Lake Sediments. Front Microbiol 2016; 7:1316. [PMID: 27597850 PMCID: PMC4992681 DOI: 10.3389/fmicb.2016.01316] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 08/09/2016] [Indexed: 11/15/2022] Open
Abstract
Syntrophic methanogenesis is an essential link in the global carbon cycle and a key bioprocess for the disposal of organic waste and production of biogas. Recent studies suggest direct interspecies electron transfer (DIET) is involved in electron exchange in methanogenesis occurring in paddy soils, anaerobic digesters, and specific co-cultures with Geobacter. In this study, we evaluate the possible involvement of DIET in the syntrophic oxidation of butyrate in the enrichments from two lake sediments (an urban lake and a natural lake). The results showed that the production of CH4 was significantly accelerated in the presence of conductive nanoscale Fe3O4 or carbon nanotubes in the sediment enrichments. Observations made with fluorescence in situ hybridization and scanning electron microscope indicated that microbial aggregates were formed in the enrichments. It appeared that the average cell-to-cell distance in aggregates in nanomaterial-amended enrichments was larger than that in aggregates in the non-amended control. These results suggested that DIET-mediated syntrophic methanogenesis could occur in the lake sediments in the presence of conductive materials. Microbial community analysis of the enrichments revealed that the genera of Syntrophomonas, Sulfurospirillum, Methanosarcina, and Methanoregula were responsible for syntrophic oxidation of butyrate in lake sediment samples. The mechanism for the conductive-material-facilitated DIET in butyrate syntrophy deserves further investigation.
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Affiliation(s)
- Jianchao Zhang
- College of Urban and Environmental Sciences, Peking University Beijing, China
| | - Yahai Lu
- College of Urban and Environmental Sciences, Peking University Beijing, China
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66
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Teng W, Liu G, Luo H, Zhang R, Xiang Y. Simultaneous sulfate and zinc removal from acid wastewater using an acidophilic and autotrophic biocathode. JOURNAL OF HAZARDOUS MATERIALS 2016; 304:159-165. [PMID: 26561748 DOI: 10.1016/j.jhazmat.2015.10.050] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 10/21/2015] [Accepted: 10/23/2015] [Indexed: 06/05/2023]
Abstract
The aim of this study was to develop microbial electrolysis cell (MEC) with a novel acidophilic and autotrophic biocathode for treatment of acid wastewater. A biocathode was developed using acidophilic sulfate-reducing bacteria as the catalyst. Artificial wastewater with 200mgL(-1) sulfate and different Zn concentrations (0, 15, 25, and 40 mg L(-1)) was used as the MEC catholyte. The acidophilic biocathode dominated by Desulfovibrio sp. with an abundance of 66% (with 82% of Desulfovibrio sequences similar to Desulfovibrio simplex) and achieved a considerable sulfate reductive rate of 32 gm(-3)d(-1). With 15 mg L(-1) Zn added, the sulfate reductive rate of MEC improved by 16%. The formation of ZnS alleviated the inhibition from sulfide and sped the sulfate reduction. With 15 and 25 mgL(-1) Zn added, more than 99% of Zn was removed from the wastewater. Dissolved Zn ions in the catholyte were converted into insoluble Zn compounds, such as zinc sulfide and zinc hydroxide, due to the sulfide and elevated pH produced by sulfate reduction. The MEC with acidophilic and autotrophic biocathode can be used as an alternative to simultaneously remove sulfate and metals from acid wastewaters, such as acid mine drainage.
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Affiliation(s)
- Wenkai Teng
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, Guangdong, China
| | - Guangli Liu
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, Guangdong, China
| | - Haiping Luo
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, Guangdong, China.
| | - Renduo Zhang
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, Guangdong, China
| | - Yinbo Xiang
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, Guangdong, China
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67
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Holmes D, Smith J. Biologically Produced Methane as a Renewable Energy Source. ADVANCES IN APPLIED MICROBIOLOGY 2016; 97:1-61. [PMID: 27926429 DOI: 10.1016/bs.aambs.2016.09.001] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Methanogens are a unique group of strictly anaerobic archaea that are more metabolically diverse than previously thought. Traditionally, it was thought that methanogens could only generate methane by coupling the oxidation of products formed by fermentative bacteria with the reduction of CO2. However, it has recently been observed that many methanogens can also use electrons extruded from metal-respiring bacteria, biocathodes, or insoluble electron shuttles as energy sources. Methanogens are found in both human-made and natural environments and are responsible for the production of ∼71% of the global atmospheric methane. Their habitats range from the human digestive tract to hydrothermal vents. Although biologically produced methane can negatively impact the environment if released into the atmosphere, when captured, it can serve as a potent fuel source. The anaerobic digestion of wastes such as animal manure, human sewage, or food waste produces biogas which is composed of ∼60% methane. Methane from biogas can be cleaned to yield purified methane (biomethane) that can be readily incorporated into natural gas pipelines making it a promising renewable energy source. Conventional anaerobic digestion is limited by long retention times, low organics removal efficiencies, and low biogas production rates. Therefore, many studies are being conducted to improve the anaerobic digestion process. Researchers have found that addition of conductive materials and/or electrically active cathodes to anaerobic digesters can stimulate the digestion process and increase methane content of biogas. It is hoped that optimization of anaerobic digesters will make biogas more readily accessible to the average person.
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Draft Genome of Thermanaerothrix daxensis GNS-1, a Thermophilic Facultative Anaerobe from the Chloroflexi Class Anaerolineae. GENOME ANNOUNCEMENTS 2015; 3:3/6/e01354-15. [PMID: 26586891 PMCID: PMC4653793 DOI: 10.1128/genomea.01354-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We present the draft genome of Thermanaerothrix daxensis GNS-1, a thermophilic member of the Chloroflexi phylum. This organism was initially characterized as a nonmotile, strictly anaerobic fermenter; however, genome analysis demonstrates that it encodes genes for a flagellum and multiple pathways for aerobic and anaerobic respiration.
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Batlle-Vilanova P, Puig S, Gonzalez-Olmos R, Vilajeliu-Pons A, Balaguer MD, Colprim J. Deciphering the electron transfer mechanisms for biogas upgrading to biomethane within a mixed culture biocathode. RSC Adv 2015. [DOI: 10.1039/c5ra09039c] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
This study describes the electron transfer mechanism of a BES fed with the effluent from water scrubbing to improve biogas upgrading.
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Affiliation(s)
| | - Sebastià Puig
- LEQUiA
- Institute of the Environment
- University of Girona
- E-17071 Girona
- Spain
| | | | | | - M. Dolors Balaguer
- LEQUiA
- Institute of the Environment
- University of Girona
- E-17071 Girona
- Spain
| | - Jesús Colprim
- LEQUiA
- Institute of the Environment
- University of Girona
- E-17071 Girona
- Spain
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