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Vasmara C, Cazaudehore G, Ceotto E, Marchetti R, Sambusiti C, Monlau F. Alkali, thermal, or thermo-alkali pre-treatment to improve the anaerobic digestion of poly(lactic acid)? WATER RESEARCH 2024; 258:121744. [PMID: 38754301 DOI: 10.1016/j.watres.2024.121744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 03/26/2024] [Accepted: 05/05/2024] [Indexed: 05/18/2024]
Abstract
Replacing petroleum-based plastics with biodegradable polymers is a major challenge for modern society especially for food packaging applications. To date, poly(lactic acid) represents 25 % of the total biodegradable plastics and it is estimated that, in the future, it could become the main contributor to the biodegradable plastics industry. Anaerobic digestion is an interesting way for the poly(lactic acid) end of life, even if its biodegradability is limited in mesophilic conditions. The aims of this study were to identify the best pre-treatment for maximizing the methane yield, minimizing the anaerobic digestion duration and limiting residual plastic fragments in the digestate. A systematic comparison was carried out between thermal, chemical, and thermo-chemical pre-treatment. Pre-treatment with 4 M KOH for 48 h at 35°C was effective in improving the mesophilic anaerobic digestion of the poly(lactic acid). Such pre-treatment allows obtaining 90 % of the theoretical methane potential, in 24 - 30 days. Importantly, such pre-treatment completely solubilized the poly(lactic acid), leaving no solid residues in the digestate. In addition, using KOH permits to avoid the sodication of the soil due to the digestate application as fertilizer.
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Affiliation(s)
- C Vasmara
- CREA, Council for Agricultural Research and Economics, Research Centre for Animal Production and Aquaculture, Via Salaria 31, Monterotondo, Rome 00015, Italy.
| | - G Cazaudehore
- APESA, Pôle Valorisation, Montardon 64121, France; Universite de Pau et des Pays de l 'Adour / E2S UPPA / CNRS, IPREM UMR5254, Institut des Sciences Analytiques et de Physicochimie pour l'Environnement et les Matériaux, Chimie et Microbiologie de l'Environnement, Pau 64000, France
| | - E Ceotto
- CREA, Council for Agricultural Research and Economics, Research Centre for Animal Production and Aquaculture, Via Beccastecca 345, S. Cesario sul Panaro, Modena 41018, Italy
| | - R Marchetti
- CREA, Council for Agricultural Research and Economics, Research Centre for Animal Production and Aquaculture, Via Beccastecca 345, S. Cesario sul Panaro, Modena 41018, Italy
| | - C Sambusiti
- Total Energies OneTech R&D, CSTJF - Avenue Larribau, Pau 64018, France
| | - F Monlau
- APESA, Pôle Valorisation, Montardon 64121, France; Total Energies OneTech R&D, PERL - Pôle D'Etudes et de Recherche de Lacq, Pôle Economique 2, BP 47 - RD 817, Lacq 64170, France
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2
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Chen G, Wang R, Sun M, Chen J, Iyobosa E, Zhao J. Carbon dioxide reduction to high-value chemicals in microbial electrosynthesis system: Biological conversion and regulation strategies. CHEMOSPHERE 2023; 344:140251. [PMID: 37769909 DOI: 10.1016/j.chemosphere.2023.140251] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/19/2023] [Accepted: 09/21/2023] [Indexed: 10/03/2023]
Abstract
Large emissions of atmospheric carbon dioxide (CO2) are causing climatic and environmental problems. It is crucial to capture and utilize the excess CO2 through diverse methods, among which the microbial electrosynthesis (MES) system has become an attractive and promising technology to mitigate greenhouse effects while reducing CO2 to high-value chemicals. However, the biological conversion and metabolic pathways through microbial catalysis have not been clearly elucidated. This review first introduces the main acetogenic bacteria for CO2 reduction and extracellular electron transfer mechanisms in MES. It then intensively analyzes the CO2 bioconversion pathways and carbon chain elongation processes in MES, together with energy supply and utilization. The factors affecting MES performance, including physical, chemical, and biological aspects, are summarized, and the strategies to promote and regulate bioconversion in MES are explored. Finally, challenges and perspectives concerning microbial electrochemical carbon sequestration are proposed, and suggestions for future research are also provided. This review provides theoretical foundation and technical support for further development and industrial application of MES for CO2 reduction.
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Affiliation(s)
- Gaoxiang Chen
- Key Laboratory of Yangtze Aquatic Environment (MOE), College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, Shanghai, PR China
| | - Rongchang Wang
- Key Laboratory of Yangtze Aquatic Environment (MOE), College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, Shanghai, PR China.
| | - Maoxin Sun
- Key Laboratory of Yangtze Aquatic Environment (MOE), College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, Shanghai, PR China
| | - Jie Chen
- Key Laboratory of Yangtze Aquatic Environment (MOE), College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, Shanghai, PR China
| | - Eheneden Iyobosa
- Key Laboratory of Yangtze Aquatic Environment (MOE), College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, Shanghai, PR China
| | - Jianfu Zhao
- Key Laboratory of Yangtze Aquatic Environment (MOE), College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, Shanghai, PR China
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Li W, Zhu L, Wu B, Liu Y, Li J, Xu L, Huangfu X, Shi D, Gu L, Chen C. Improving mesophilic anaerobic digestion of food waste by side-stream thermophilic reactor: Activation of methanogenic, key enzymes and metabolism. WATER RESEARCH 2023; 241:120167. [PMID: 37290195 DOI: 10.1016/j.watres.2023.120167] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 05/21/2023] [Accepted: 06/01/2023] [Indexed: 06/10/2023]
Abstract
Anaerobic digestion (AD) is a favorable way to convert organic pollutants, such as food waste (FW), into clean energy through microbial action. This work adopted a side-stream thermophilic anaerobic digestion (STA) strategy to improve a digestive system's efficiency and stability. Results showed that the STA strategy brought higher methane production as well as higher system stability. It quickly adapted to thermal stimulation and increased the specific methane production from 359 mL CH4/g·VS to 439 mL CH4/g·VS, which was also higher than 317 mL CH4/g·VS from single-stage thermophilic anaerobic digestion. Further exploration of the mechanism of STA using metagenomic and metaproteomic analysis revealed enhanced activity of key enzymes. The main metabolic pathway was up-regulated, while the dominant bacteria were concentrated, and the multifunctional Methanosarcina was enriched. These results indicate that STA optimized organic metabolism patterns, comprehensively promoted methane production pathways, and formed various energy conservation mechanisms. Further, the system's limited heating avoided adverse effects from thermal stimulation, and activated enzyme activity and heat shock proteins through circulating slurries, which improved the metabolic process, showing great application potential.
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Affiliation(s)
- Wen Li
- Key laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing, 400045, PR China
| | - Lirong Zhu
- Key laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing, 400045, PR China
| | - Baocun Wu
- Key laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing, 400045, PR China
| | - Yongli Liu
- Key laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing, 400045, PR China
| | - Jinze Li
- Key laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing, 400045, PR China
| | - Linji Xu
- Key laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing, 400045, PR China
| | - Xiaoliu Huangfu
- Key laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing, 400045, PR China
| | - Dezhi Shi
- Key laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing, 400045, PR China
| | - Li Gu
- Key laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing, 400045, PR China.
| | - Cong Chen
- Key laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing, 400045, PR China
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Exploring the Interspecific Interactions and the Metabolome of the Soil Isolate Hylemonella gracilis. mSystems 2023; 8:e0057422. [PMID: 36537799 PMCID: PMC9948732 DOI: 10.1128/msystems.00574-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Microbial community analysis of aquatic environments showed that an important component of its microbial diversity consists of bacteria with cell sizes of ~0.1 μm. Such small bacteria can show genomic reductions and metabolic dependencies with other bacteria. However, so far, no study has investigated if such bacteria exist in terrestrial environments like soil. Here, we isolated soil bacteria that passed through a 0.1-μm filter. The complete genome of one of the isolates was sequenced and the bacterium was identified as Hylemonella gracilis. A set of coculture assays with phylogenetically distant soil bacteria with different cell and genome sizes was performed. The coculture assays revealed that H. gracilis grows better when interacting with other soil bacteria like Paenibacillus sp. AD87 and Serratia plymuthica. Transcriptomics and metabolomics showed that H. gracilis was able to change gene expression, behavior, and biochemistry of the interacting bacteria without direct cell-cell contact. Our study indicates that in soil there are bacteria that can pass through a 0.1-μm filter. These bacteria may have been overlooked in previous research on soil microbial communities. Such small bacteria, exemplified here by H. gracilis, can induce transcriptional and metabolomic changes in other bacteria upon their interactions in soil. In vitro, the studied interspecific interactions allowed utilization of growth substrates that could not be utilized by monocultures, suggesting that biochemical interactions between substantially different sized soil bacteria may contribute to the symbiosis of soil bacterial communities. IMPORTANCE Analysis of aquatic microbial communities revealed that parts of its diversity consist of bacteria with cell sizes of ~0.1 μm. Such bacteria can show genomic reductions and metabolic dependencies with other bacteria. So far, no study investigated if such bacteria exist in terrestrial environments such as soil. Here, we show that such bacteria also exist in soil. The isolated bacteria were identified as Hylemonella gracilis. Coculture assays with phylogenetically different soil bacteria revealed that H. gracilis grows better when cocultured with other soil bacteria. Transcriptomics and metabolomics showed that H. gracilis was able to change gene expression, behavior, and biochemistry of the interacting bacteria without direct contact. Our study revealed that bacteria are present in soil that can pass through 0.1-μm filters. Such bacteria may have been overlooked in previous research on soil microbial communities and may contribute to the symbiosis of soil bacterial communities.
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Eigentler L, Davidson FA, Stanley-Wall NR. Mechanisms driving spatial distribution of residents in colony biofilms: an interdisciplinary perspective. Open Biol 2022; 12:220194. [PMID: 36514980 PMCID: PMC9748781 DOI: 10.1098/rsob.220194] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Biofilms are consortia of microorganisms that form collectives through the excretion of extracellular matrix compounds. The importance of biofilms in biological, industrial and medical settings has long been recognized due to their emergent properties and impact on surrounding environments. In laboratory situations, one commonly used approach to study biofilm formation mechanisms is the colony biofilm assay, in which cell communities grow on solid-gas interfaces on agar plates after the deposition of a population of founder cells. The residents of a colony biofilm can self-organize to form intricate spatial distributions. The assay is ideally suited to coupling with mathematical modelling due to the ability to extract a wide range of metrics. In this review, we highlight how interdisciplinary approaches have provided deep insights into mechanisms causing the emergence of these spatial distributions from well-mixed inocula.
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Affiliation(s)
- Lukas Eigentler
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK,Mathematics, School of Science and Engineering, University of Dundee, Dundee DD1 4HN, UK
| | - Fordyce A. Davidson
- Mathematics, School of Science and Engineering, University of Dundee, Dundee DD1 4HN, UK
| | - Nicola R. Stanley-Wall
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
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6
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Foster-Nyarko E, Pallen MJ. The microbial ecology of Escherichia coli in the vertebrate gut. FEMS Microbiol Rev 2022; 46:fuac008. [PMID: 35134909 PMCID: PMC9075585 DOI: 10.1093/femsre/fuac008] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 01/31/2022] [Accepted: 02/01/2022] [Indexed: 11/13/2022] Open
Abstract
Escherichia coli has a rich history as biology's 'rock star', driving advances across many fields. In the wild, E. coli resides innocuously in the gut of humans and animals but is also a versatile pathogen commonly associated with intestinal and extraintestinal infections and antimicrobial resistance-including large foodborne outbreaks such as the one that swept across Europe in 2011, killing 54 individuals and causing approximately 4000 infections and 900 cases of haemolytic uraemic syndrome. Given that most E. coli are harmless gut colonizers, an important ecological question plaguing microbiologists is what makes E. coli an occasionally devastating pathogen? To address this question requires an enhanced understanding of the ecology of the organism as a commensal. Here, we review how our knowledge of the ecology and within-host diversity of this organism in the vertebrate gut has progressed in the 137 years since E. coli was first described. We also review current approaches to the study of within-host bacterial diversity. In closing, we discuss some of the outstanding questions yet to be addressed and prospects for future research.
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Affiliation(s)
- Ebenezer Foster-Nyarko
- Quadram Institute Bioscience, Norwich Research Park, Norwich, NR4 7UQ, United Kingdom
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Mark J Pallen
- Quadram Institute Bioscience, Norwich Research Park, Norwich, NR4 7UQ, United Kingdom
- School of Veterinary Medicine, University of Surrey, Guildford, Surrey, GU2 7AL, United Kingdom
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TU, United Kingdom
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7
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Yang HY, Hou NN, Wang YX, Liu J, He CS, Wang YR, Li WH, Mu Y. Mixed-culture biocathodes for acetate production from CO 2 reduction in the microbial electrosynthesis: Impact of temperature. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 790:148128. [PMID: 34098277 DOI: 10.1016/j.scitotenv.2021.148128] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/26/2021] [Accepted: 05/26/2021] [Indexed: 06/12/2023]
Abstract
The temperature effect on bioelectrochemical reduction of CO2 to acetate with a mixed-culture biocathode in the microbial electrosynthesis was explored. The results showed that maximum acetate amount of 525.84 ± 1.55 mg L-1 and fastest acetate formation of 49.21 ± 0.49 mg L-1 d-1 were obtained under mesophilic conditions. Electron recovery efficiency for CO2 reduction to acetate ranged from 14.50 ± 2.20% to 64.86 ± 2.20%, due to propionate, butyrate and H2 generation. Mesophilic conditions were demonstrated to be more favorable for biofilm formation on the cathode, resulting in a stable and dense biofilm. At phylum level, the relative abundance of Bacteroidetes phylum in the biofilm remarkably increased under mesophilic conditions, compared with that at psychrophilic and thermophilic conditions. At genus level, the Clostridium, Treponema, Acidithiobacillus, Acetobacterium and Acetoanaerobium were found to be dominated genera in the biofilm under mesophilic conditions, while genera diversity decreased under psychrophilic and thermophilic conditions.
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Affiliation(s)
- Hou-Yun Yang
- CAS Key Laboratory for Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science & Technology of China, Hefei, China; Key Laboratory of Water Pollution Control and Wastewater Reuse of Anhui Province, Anhui Provincial Key Laboratory of Environmental Pollution Control and Resource Reuse, Anhui Jianzhu University, Hefei, China
| | - Nan-Nan Hou
- CAS Key Laboratory for Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science & Technology of China, Hefei, China; School of Physics and Materials Engineering, Hefei Normal University, Hefei, China
| | - Yi-Xuan Wang
- CAS Key Laboratory for Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science & Technology of China, Hefei, China.
| | - Jing Liu
- CAS Key Laboratory for Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science & Technology of China, Hefei, China
| | - Chuan-Shu He
- CAS Key Laboratory for Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science & Technology of China, Hefei, China
| | - Yi-Ran Wang
- CAS Key Laboratory for Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science & Technology of China, Hefei, China
| | - Wei-Hua Li
- Key Laboratory of Water Pollution Control and Wastewater Reuse of Anhui Province, Anhui Provincial Key Laboratory of Environmental Pollution Control and Resource Reuse, Anhui Jianzhu University, Hefei, China
| | - Yang Mu
- CAS Key Laboratory for Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science & Technology of China, Hefei, China
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Engineering Cooperation in an Anaerobic Coculture. Appl Environ Microbiol 2021; 87:AEM.02852-20. [PMID: 33771781 DOI: 10.1128/aem.02852-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 03/19/2021] [Indexed: 01/28/2023] Open
Abstract
Over the past century, microbiologists have studied organisms in pure culture, yet it is becoming increasingly apparent that the majority of biological processes rely on multispecies cooperation and interaction. While little is known about how such interactions permit cooperation, even less is known about how cooperation arises. To study the emergence of cooperation in the laboratory, we constructed both a commensal community and an obligate mutualism using the previously noninteracting bacteria Shewanella oneidensis and Geobacter sulfurreducens Incorporation of a glycerol utilization plasmid (pGUT2) enabled S. oneidensis to metabolize glycerol and produce acetate as a carbon source for G. sulfurreducens, establishing a cross-feeding, commensal coculture. In the commensal coculture, both species coupled oxidative metabolism to the respiration of fumarate as the terminal electron acceptor. Deletion of the gene encoding fumarate reductase in the S. oneidensis/pGUT2 strain shifted the coculture with G. sulfurreducens to an obligate mutualism where neither species could grow in the absence of the other. A shift in metabolic strategy from glycerol catabolism to malate metabolism was associated with obligate coculture growth. Further targeted deletions in malate uptake and acetate generation pathways in S. oneidensis significantly inhibited coculture growth with G. sulfurreducens The engineered coculture between S. oneidensis and G. sulfurreducens provides a model laboratory system to study the emergence of cooperation in bacterial communities, and the shift in metabolic strategy observed in the obligate coculture highlights the importance of genetic change in shaping microbial interactions in the environment.IMPORTANCE Microbes seldom live alone in the environment, yet this scenario is approximated in the vast majority of pure-culture laboratory experiments. Here, we develop an anaerobic coculture system to begin understanding microbial physiology in a more complex setting but also to determine how anaerobic microbial communities can form. Using synthetic biology, we generated a coculture system where the facultative anaerobe Shewanella oneidensis consumes glycerol and provides acetate to the strict anaerobe Geobacter sulfurreducens In the commensal system, growth of G. sulfurreducens is dependent on the presence of S. oneidensis To generate an obligate coculture, where each organism requires the other, we eliminated the ability of S. oneidensis to respire fumarate. An unexpected shift in metabolic strategy from glycerol catabolism to malate metabolism was observed in the obligate coculture. Our work highlights how metabolic landscapes can be expanded in multispecies communities and provides a system to evaluate the evolution of cooperation under anaerobic conditions.
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Aiyer KS. Synergistic effects in a microbial fuel cell between co-cultures and a photosynthetic alga Chlorella vulgaris improve performance. Heliyon 2021; 7:e05935. [PMID: 33490687 PMCID: PMC7810779 DOI: 10.1016/j.heliyon.2021.e05935] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/21/2020] [Accepted: 01/06/2021] [Indexed: 12/01/2022] Open
Abstract
Microbial communities are catalysts that drive the operation of microbial fuel cells (MFCs). In this study, the use of a defined co-culture of Escherichia coli and Pseudomonas aeruginosa towards improved power generation in MFCs is described. The co-culture has been initially evaluated for substrate consumption, biofilm formation and microbial electron transfer activity. The co-culture gave an enhanced power density of 190.44 mW m−2, while E. coli and P. aeruginosa as pure cultures generated lesser power densities of 139.24 and 158.76 mW m−2 respectively. The photosynthetic alga Chlorella vulgaris was then inoculated in the cathode chamber. Co-cultures in the presence of C. vulgaris improved the mean power density from 175 mW m−2 to 248 mW m−2, a 41.7% rise. A synergistic effect was observed when the co-cultures were coupled with C. vulgaris. Combining co-cultures with photosynthetic MFCs offers a lot of promise in studying mechanisms and expanding the nature of applications.
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Affiliation(s)
- Kartik S Aiyer
- Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Puttaparthi, Andhra Pradesh 515134, India
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10
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Methanogenesis inhibitors used in bio-electrochemical systems: A review revealing reality to decide future direction and applications. BIORESOURCE TECHNOLOGY 2020; 319:124141. [PMID: 32977094 DOI: 10.1016/j.biortech.2020.124141] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 09/11/2020] [Accepted: 09/13/2020] [Indexed: 02/08/2023]
Abstract
Microbial fuel cell (MFC) is a robust technology capable of treating real wastewaters by utilizing mixed anaerobic microbiota as inoculum for producing electricity from oxidation of the biodegradable matters. However, these mixed microbiota comprises of both electroactive microorganisms (EAM) and substrate/electron scavenging microorganisms such as methanogens. Hence, in order to maximize bioelectricity from MFC, different physio-chemical techniques have been applied in past investigations to suppress activity of methanogens. Interestingly, recent investigations exhibit that methanogens can produce electricity in MFC and possess the cellular machinery like cytochrome c and Type IV pili to perform extracellular electron transfer (EET) in the presence of suitable electron acceptors. Hence, in this review, in-depth analysis of versatile behaviour of methanogens in both MFC and natural anaerobic conditions with different inhibition techniques is explored. This review also discusses the future research directions based on the latest scientific evidence on role of methanogens for EET in MFC.
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11
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Zhao F, Heidrich ES, Curtis TP, Dolfing J. Understanding the complexity of wastewater: The combined impacts of carbohydrates and sulphate on the performance of bioelectrochemical systems. WATER RESEARCH 2020; 176:115737. [PMID: 32240846 DOI: 10.1016/j.watres.2020.115737] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 03/11/2020] [Accepted: 03/17/2020] [Indexed: 06/11/2023]
Abstract
Bioelectrochemical systems (BES) have long been viewed as a promising wastewater treatment technology. However, in reality, the performance of bioelectrochemical systems fed with real (and therefore complex) wastewaters is often disappointing. We have sought to investigate the combined impacts of complex substrates and presence of electron acceptors. In particular, this study illustrates and systematically evaluates the disparity in performance between a BES acclimatised with acetate and those acclimatised with more complex carbohydrates (glucose, sucrose or starch) and in the presence and absence of sulphate. Relative to acetate only, operating with complex carbohydrates reduced current by 73%-87% and coulombic efficiency by 4%-50%. Acclimation with complex carbohydrates seriously impeded the colonisation anode by Geobacteraceae, resulting in substantially reduced capacity to produce current (60.2% on average). Combined acclimation with sulphate further reduced current by 35% on average, and resulted in a total reduction of 83%-93% relative to the acetate control. However, the presence of an electrogenic sulphide-sulphur shuttle meant sulphate had little effect on the coulombic efficiency of the BES. The results indicate that a reduction in current and coulombic efficiency is, at present, an unavoidable consequence of operating a BES fed with complex wastewater. Researchers, designers and policy makers should incorporate such losses in both their plans and their prognostications.
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Affiliation(s)
- Fei Zhao
- School of Engineering, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, England, UK
| | - Elizabeth S Heidrich
- School of Engineering, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, England, UK
| | - Thomas P Curtis
- School of Engineering, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, England, UK
| | - Jan Dolfing
- School of Engineering, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, England, UK.
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12
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Wang PH, Correia K, Ho HC, Venayak N, Nemr K, Flick R, Mahadevan R, Edwards EA. An interspecies malate-pyruvate shuttle reconciles redox imbalance in an anaerobic microbial community. ISME JOURNAL 2019; 13:1042-1055. [PMID: 30607026 DOI: 10.1038/s41396-018-0333-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 11/26/2018] [Accepted: 11/29/2018] [Indexed: 11/09/2022]
Abstract
Microbes in ecosystems often develop coordinated metabolic interactions. Therefore, understanding metabolic interdependencies between microbes is critical to deciphering ecosystem function. In this study, we sought to deconstruct metabolic interdependencies in organohalide-respiring consortium ACT-3 containing Dehalobacter restrictus using a combination of metabolic modeling and experimental validation. D. restrictus possesses a complete set of genes for amino acid biosynthesis yet when grown in isolation requires amino acid supplementation. We reconciled this discrepancy using flux balance analysis considering cofactor availability, enzyme promiscuity, and shared protein expression patterns for several D. restrictus strains. Experimentally, 13C incorporation assays, growth assays, and metabolite analysis of D. restrictus strain PER-K23 cultures were performed to validate the model predictions. The model resolved that the amino acid dependency of D. restrictus resulted from restricted NADPH regeneration and predicted that malate supplementation would replenish intracellular NADPH. Interestingly, we observed unexpected export of pyruvate and glutamate in parallel to malate consumption in strain PER-K23 cultures. Further experimental analysis using the ACT-3 transfer cultures suggested the occurrence of an interspecies malate-pyruvate shuttle reconciling a redox imbalance, reminiscent of the mitochondrial malate shunt pathway in eukaryotic cells. Altogether, this study suggests that redox imbalance and metabolic complementarity are important driving forces for metabolite exchange in anaerobic microbial communities.
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Affiliation(s)
- Po-Hsiang Wang
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada
| | - Kevin Correia
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada
| | - Han-Chen Ho
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada
| | - Naveen Venayak
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada
| | - Kayla Nemr
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada
| | - Robert Flick
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada
| | - Radhakrishnan Mahadevan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada.
| | - Elizabeth A Edwards
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada.
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13
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Molaey R, Bayrakdar A, Çalli B. Long-term influence of trace element deficiency on anaerobic mono-digestion of chicken manure. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2018; 223:743-748. [PMID: 29986321 DOI: 10.1016/j.jenvman.2018.06.090] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 06/14/2018] [Accepted: 06/28/2018] [Indexed: 06/08/2023]
Abstract
Recent findings showed that some trace elements essential for anaerobic digestion might be deficient in chicken (laying hens) manure. In this study, the long-term influence of trace element deficiency on anaerobic mono-digestion of chicken manure was investigated. Three bench-scale anaerobic reactors were operated with or without trace element supplementation. As trace element, only Se or a mix containing Co, Mo, Ni, Se, and W was added to the reactors. The results revealed that in anaerobic digestion of chicken manure at total ammonium nitrogen concentrations over 6000 mg L-1, Se supplementation was critical but not sufficient alone for long-term stable CH4 production. Addition of a mix consisting of Co, Mo, Ni, Se and W resulted in a more stable digestion performance. Daily trace element mix supplementation promoted the hydrogenotrophic Methanoculleus bourgensis, which is an ammonia tolerant methanogen. The decrease in the relative abundance of Methanoculleus detected after termination of trace element addition and resulted in accumulation of acetate and propionate that followed by a significant decrease in CH4 production.
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Affiliation(s)
- Rahim Molaey
- Environmental Engineering Department, Marmara University, 34722 Kadikoy, Istanbul, Turkey; Kabul Polytechnic University, 5th District, Red Crescent Avenue, Kabul, Afghanistan.
| | - Alper Bayrakdar
- Environmental Engineering Department, Marmara University, 34722 Kadikoy, Istanbul, Turkey; Environmental Engineering Department, Necmettin Erbakan University, 42140 Meram, Konya, Turkey.
| | - Bariş Çalli
- Environmental Engineering Department, Marmara University, 34722 Kadikoy, Istanbul, Turkey.
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14
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Geesink P, Tyc O, Küsel K, Taubert M, van de Velde C, Kumar S, Garbeva P. Growth promotion and inhibition induced by interactions of groundwater bacteria. FEMS Microbiol Ecol 2018; 94:5076029. [DOI: 10.1093/femsec/fiy164] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 08/17/2018] [Indexed: 11/14/2022] Open
Affiliation(s)
- Patricia Geesink
- Aquatic Geomicrobiology, Institute of Biodiversity, Friedrich Schiller University Jena, Germany
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Olaf Tyc
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Kirsten Küsel
- Aquatic Geomicrobiology, Institute of Biodiversity, Friedrich Schiller University Jena, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
| | - Martin Taubert
- Aquatic Geomicrobiology, Institute of Biodiversity, Friedrich Schiller University Jena, Germany
| | - Charlotte van de Velde
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Swatantar Kumar
- Aquatic Geomicrobiology, Institute of Biodiversity, Friedrich Schiller University Jena, Germany
| | - Paolina Garbeva
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
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15
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Daghio M, Aulenta F, Vaiopoulou E, Franzetti A, Arends JBA, Sherry A, Suárez-Suárez A, Head IM, Bestetti G, Rabaey K. Electrobioremediation of oil spills. WATER RESEARCH 2017; 114:351-370. [PMID: 28279880 DOI: 10.1016/j.watres.2017.02.030] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 01/27/2017] [Accepted: 02/14/2017] [Indexed: 05/20/2023]
Abstract
Annually, thousands of oil spills occur across the globe. As a result, petroleum substances and petrochemical compounds are widespread contaminants causing concern due to their toxicity and recalcitrance. Many remediation strategies have been developed using both physicochemical and biological approaches. Biological strategies are most benign, aiming to enhance microbial metabolic activities by supplying limiting inorganic nutrients, electron acceptors or donors, thus stimulating oxidation or reduction of contaminants. A key issue is controlling the supply of electron donors/acceptors. Bioelectrochemical systems (BES) have emerged, in which an electrical current serves as either electron donor or acceptor for oil spill bioremediation. BES are highly controllable and can possibly also serve as biosensors for real time monitoring of the degradation process. Despite being promising, multiple aspects need to be considered to make BES suitable for field applications including system design, electrode materials, operational parameters, mode of action and radius of influence. The microbiological processes, involved in bioelectrochemical contaminant degradation, are currently not fully understood, particularly in relation to electron transfer mechanisms. Especially in sulfate rich environments, the sulfur cycle appears pivotal during hydrocarbon oxidation. This review provides a comprehensive analysis of the research on bioelectrochemical remediation of oil spills and of the key parameters involved in the process.
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Affiliation(s)
- Matteo Daghio
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126 Milan, Italy.
| | - Federico Aulenta
- Water Research Institute (IRSA), National Research Council (CNR), Via Salaria km 29,300, 00015 Monterotondo, RM, Italy
| | - Eleni Vaiopoulou
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, B-9000 Gent, Belgium
| | - Andrea Franzetti
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126 Milan, Italy
| | - Jan B A Arends
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, B-9000 Gent, Belgium
| | - Angela Sherry
- School of Civil Engineering & Geosciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - Ana Suárez-Suárez
- School of Civil Engineering & Geosciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - Ian M Head
- School of Civil Engineering & Geosciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - Giuseppina Bestetti
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126 Milan, Italy
| | - Korneel Rabaey
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, B-9000 Gent, Belgium.
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16
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Resilience, Dynamics, and Interactions within a Model Multispecies Exoelectrogenic-Biofilm Community. Appl Environ Microbiol 2017; 83:AEM.03033-16. [PMID: 28087529 DOI: 10.1128/aem.03033-16] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 01/02/2017] [Indexed: 01/08/2023] Open
Abstract
Anode-associated multispecies exoelectrogenic biofilms are essential for the function of bioelectrochemical systems (BESs). The individual activities of anode-associated organisms and physiological responses resulting from coculturing are often hard to assess due to the high microbial diversity in these systems. Therefore, we developed a model multispecies biofilm comprising three exoelectrogenic proteobacteria, Shewanella oneidensis, Geobacter sulfurreducens, and Geobacter metallireducens, with the aim to study in detail the biofilm formation dynamics, the interactions between the organisms, and the overall activity of an exoelectrogenic biofilm as a consequence of the applied anode potential. The experiments revealed that the organisms build a stable biofilm on an electrode surface that is rather resilient to changes in the redox potential of the anode. The community operated at maximum electron transfer rates at electrode potentials that were higher than 0.04 V versus a normal hydrogen electrode. Current densities decreased gradually with lower potentials and reached half-maximal values at -0.08 V. Transcriptomic results point toward a positive interaction among the individual strains. S. oneidensis and G. sulfurreducens upregulated their central metabolisms as a response to cultivation under mixed-species conditions. G. sulfurreducens was detected in the planktonic phase of the bioelectrochemical reactors in mixed-culture experiments but not when it was grown in the absence of the other two organisms.IMPORTANCE In many cases, multispecies communities can convert organic substrates into electric power more efficiently than axenic cultures, a phenomenon that remains unresolved. In this study, we aimed to elucidate the potential mutual effects of multispecies communities in bioelectrochemical systems to understand how microbes interact in the coculture anodic network and to improve the community's conversion efficiency for organic substrates into electrical energy. The results reveal positive interactions that might lead to accelerated electron transfer in mixed-species anode communities. The observations made within this model biofilm might be applicable to a variety of nonaxenic systems in the field.
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17
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Macke E, Tasiemski A, Massol F, Callens M, Decaestecker E. Life history and eco-evolutionary dynamics in light of the gut microbiota. OIKOS 2017. [DOI: 10.1111/oik.03900] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Emilie Macke
- Laboratory Aquatic Biology, KU Leuven (Kulak), Dept of Biology; E. Sabbelaan 53, BE-8500 Kortrijk Belgium
| | | | - François Massol
- Univ. Lille; CNRS UMR 8198 Evo-Eco-Paleo SPICI group Lille France
| | - Martijn Callens
- Laboratory Aquatic Biology, KU Leuven (Kulak), Dept of Biology; E. Sabbelaan 53, BE-8500 Kortrijk Belgium
| | - Ellen Decaestecker
- Laboratory Aquatic Biology, KU Leuven (Kulak), Dept of Biology; E. Sabbelaan 53, BE-8500 Kortrijk Belgium
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18
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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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19
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Vilajeliu-Pons A, Bañeras L, Puig S, Molognoni D, Vilà-Rovira A, Hernández-del Amo E, Balaguer MD, Colprim J. External Resistances Applied to MFC Affect Core Microbiome and Swine Manure Treatment Efficiencies. PLoS One 2016; 11:e0164044. [PMID: 27701451 PMCID: PMC5049776 DOI: 10.1371/journal.pone.0164044] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 09/19/2016] [Indexed: 11/19/2022] Open
Abstract
Microbial fuel cells (MFCs) can be designed to combine water treatment with concomitant electricity production. Animal manure treatment has been poorly explored using MFCs, and its implementation at full-scale primarily relies on the bacterial distribution and activity within the treatment cell. This study reports the bacterial community changes at four positions within the anode of two almost identically operated MFCs fed swine manure. Changes in the microbiome structure are described according to the MFC fluid dynamics and the application of a maximum power point tracking system (MPPT) compared to a fixed resistance system (Ref-MFC). Both external resistance and cell hydrodynamics are thought to heavily influence MFC performance. The microbiome was characterised both quantitatively (qPCR) and qualitatively (454-pyrosequencing) by targeting bacterial 16S rRNA genes. The diversity of the microbial community in the MFC biofilm was reduced and differed from the influent swine manure. The adopted electric condition (MPPT vs fixed resistance) was more relevant than the fluid dynamics in shaping the MFC microbiome. MPPT control positively affected bacterial abundance and promoted the selection of putatively exoelectrogenic bacteria in the MFC core microbiome (Sedimentibacter sp. and gammaproteobacteria). These differences in the microbiome may be responsible for the two-fold increase in power production achieved by the MPPT-MFC compared to the Ref-MFC.
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Affiliation(s)
| | - Lluis Bañeras
- Molecular Microbial Ecology Group, Institute of Aquatic Ecology, University of Girona, Girona, Spain
- * E-mail:
| | - Sebastià Puig
- LEQUiA, Institute of the Environment, University of Girona, Girona, Spain
| | - Daniele Molognoni
- Department of Civil Engineering and Architecture (D.I.C.Ar.), University of Pavia, Pavia, Italy
| | - Albert Vilà-Rovira
- LEQUiA, Institute of the Environment, University of Girona, Girona, Spain
| | - Elena Hernández-del Amo
- Molecular Microbial Ecology Group, Institute of Aquatic Ecology, University of Girona, Girona, Spain
| | - Maria D. Balaguer
- LEQUiA, Institute of the Environment, University of Girona, Girona, Spain
| | - Jesús Colprim
- LEQUiA, Institute of the Environment, University of Girona, Girona, Spain
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20
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Heidrich ES, Curtis TP, Woodcock S, Dolfing J. Quantification of effective exoelectrogens by most probable number (MPN) in a microbial fuel cell. BIORESOURCE TECHNOLOGY 2016; 218:27-30. [PMID: 27347794 DOI: 10.1016/j.biortech.2016.06.066] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 06/16/2016] [Accepted: 06/17/2016] [Indexed: 06/06/2023]
Abstract
The objective of this work was to quantify the number of exoelectrogens in wastewater capable of producing current in a microbial fuel cell by adapting the classical most probable number (MPN) methodology using current production as end point. Inoculating a series of microbial fuel cells with various dilutions of domestic wastewater and with acetate as test substrate yielded an apparent number of exoelectrogens of 17perml. Using current as a proxy for activity the apparent exoelectrogen growth rate was 0.03h(-1). With starch or wastewater as more complex test substrates similar apparent growth rates were obtained, but the apparent MPN based numbers of exoelectrogens in wastewater were significantly lower, probably because in contrast to acetate, complex substrates require complex food chains to deliver the electrons to the electrodes. Consequently, the apparent MPN is a function of the combined probabilities of members of the food chain being present.
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Affiliation(s)
- Elizabeth S Heidrich
- School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Thomas P Curtis
- School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Stephen Woodcock
- School of Mathematical Sciences, University of Technology Sydney, Sydney, Australia
| | - Jan Dolfing
- School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK.
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21
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Hodgson DM, Smith A, Dahale S, Stratford JP, Li JV, Grüning A, Bushell ME, Marchesi JR, Avignone Rossa C. Segregation of the Anodic Microbial Communities in a Microbial Fuel Cell Cascade. Front Microbiol 2016; 7:699. [PMID: 27242723 PMCID: PMC4863660 DOI: 10.3389/fmicb.2016.00699] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Accepted: 04/26/2016] [Indexed: 11/13/2022] Open
Abstract
Metabolic interactions within microbial communities are essential for the efficient degradation of complex organic compounds, and underpin natural phenomena driven by microorganisms, such as the recycling of carbon-, nitrogen-, and sulfur-containing molecules. These metabolic interactions ultimately determine the function, activity and stability of the community, and therefore their understanding would be essential to steer processes where microbial communities are involved. This is exploited in the design of microbial fuel cells (MFCs), bioelectrochemical devices that convert the chemical energy present in substrates into electrical energy through the metabolic activity of microorganisms, either single species or communities. In this work, we analyzed the evolution of the microbial community structure in a cascade of MFCs inoculated with an anaerobic microbial community and continuously fed with a complex medium. The analysis of the composition of the anodic communities revealed the establishment of different communities in the anodes of the hydraulically connected MFCs, with a decrease in the abundance of fermentative taxa and a concurrent increase in respiratory taxa along the cascade. The analysis of the metabolites in the anodic suspension showed a metabolic shift between the first and last MFC, confirming the segregation of the anodic communities. Those results suggest a metabolic interaction mechanism between the predominant fermentative bacteria at the first stages of the cascade and the anaerobic respiratory electrogenic population in the latter stages, which is reflected in the observed increase in power output. We show that our experimental system represents an ideal platform for optimization of processes where the degradation of complex substrates is involved, as well as a potential tool for the study of metabolic interactions in complex microbial communities.
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Affiliation(s)
- Douglas M Hodgson
- Department of Microbial and Cellular Sciences, University of Surrey Guildford, UK
| | - Ann Smith
- Cardiff School of Biosciences, Cardiff University Cardiff, UK
| | - Sonal Dahale
- Department of Microbial and Cellular Sciences, University of Surrey Guildford, UK
| | - James P Stratford
- Warwick Integrative Synthetic Biology Centre, University of Warwick Coventry, UK
| | - Jia V Li
- Centre for Digestive and Gut Health, Department of Surgery and Cancer, Imperial College LondonLondon, UK; Division of Computational and Systems Medicine, Department of Surgery and Cancer, Imperial College LondonLondon, UK
| | - André Grüning
- Department of Computer Science, University of Surrey Guildford, UK
| | - Michael E Bushell
- Department of Microbial and Cellular Sciences, University of Surrey Guildford, UK
| | - Julian R Marchesi
- Cardiff School of Biosciences, Cardiff UniversityCardiff, UK; Centre for Digestive and Gut Health, Department of Surgery and Cancer, Imperial College LondonLondon, UK
| | - C Avignone Rossa
- Department of Microbial and Cellular Sciences, University of Surrey Guildford, UK
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22
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Hari AR, Katuri KP, Gorron E, Logan BE, Saikaly PE. Multiple paths of electron flow to current in microbial electrolysis cells fed with low and high concentrations of propionate. Appl Microbiol Biotechnol 2016; 100:5999-6011. [PMID: 26936773 DOI: 10.1007/s00253-016-7402-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 02/14/2016] [Accepted: 02/16/2016] [Indexed: 11/25/2022]
Abstract
Microbial electrolysis cells (MECs) provide a viable approach for bioenergy generation from fermentable substrates such as propionate. However, the paths of electron flow during propionate oxidation in the anode of MECs are unknown. Here, the paths of electron flow involved in propionate oxidation in the anode of two-chambered MECs were examined at low (4.5 mM) and high (36 mM) propionate concentrations. Electron mass balances and microbial community analysis revealed that multiple paths of electron flow (via acetate/H2 or acetate/formate) to current could occur simultaneously during propionate oxidation regardless of the concentration tested. Current (57-96 %) was the largest electron sink and methane (0-2.3 %) production was relatively unimportant at both concentrations based on electron balances. At a low propionate concentration, reactors supplemented with 2-bromoethanesulfonate had slightly higher coulombic efficiencies than reactors lacking this methanogenesis inhibitor. However, an opposite trend was observed at high propionate concentration, where reactors supplemented with 2-bromoethanesulfonate had a lower coulombic efficiency and there was a greater percentage of electron loss (23.5 %) to undefined sinks compared to reactors without 2-bromoethanesulfonate (11.2 %). Propionate removal efficiencies were 98 % (low propionate concentration) and 78 % (high propionate concentration). Analysis of 16S rRNA gene pyrosequencing revealed the dominance of sequences most similar to Geobacter sulfurreducens PCA and G. sulfurreducens subsp. ethanolicus. Collectively, these results provide new insights on the paths of electron flow during propionate oxidation in the anode of MECs fed with low and high propionate concentrations.
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Affiliation(s)
- Ananda Rao Hari
- Biological and Environmental Sciences and Engineering Division, Water Desalination and Reuse Research Center, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Krishna P Katuri
- Biological and Environmental Sciences and Engineering Division, Water Desalination and Reuse Research Center, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Eduardo Gorron
- Biological and Environmental Sciences and Engineering Division, Water Desalination and Reuse Research Center, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Bruce E Logan
- Department of Civil and Environmental Engineering, The Pennsylvania State University, University Park, PA, USA
| | - Pascal E Saikaly
- Biological and Environmental Sciences and Engineering Division, Water Desalination and Reuse Research Center, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
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23
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Perspective of harnessing energy from landfill leachate via microbial fuel cells: novel biofuels and electrogenic physiologies. Appl Microbiol Biotechnol 2015; 99:7827-36. [DOI: 10.1007/s00253-015-6857-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 07/14/2015] [Accepted: 07/16/2015] [Indexed: 10/23/2022]
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24
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Rimboud M, Pocaznoi D, Erable B, Bergel A. Electroanalysis of microbial anodes for bioelectrochemical systems: basics, progress and perspectives. Phys Chem Chem Phys 2014; 16:16349-66. [DOI: 10.1039/c4cp01698j] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Over about the last ten years, microbial anodes have been the subject of a huge number of fundamental studies dealing with an increasing variety of possible application domains.
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Affiliation(s)
- M. Rimboud
- Laboratoire de Génie Chimique
- CNRS - Université de Toulouse
- 31432 Toulouse, France
| | - D. Pocaznoi
- Laboratoire de Génie Chimique
- CNRS - Université de Toulouse
- 31432 Toulouse, France
| | - B. Erable
- Laboratoire de Génie Chimique
- CNRS - Université de Toulouse
- 31432 Toulouse, France
| | - A. Bergel
- Laboratoire de Génie Chimique
- CNRS - Université de Toulouse
- 31432 Toulouse, France
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