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Resitano M, Tucci M, Mezzi A, Kaciulis S, Matturro B, D'Ugo E, Bertuccini L, Fazi S, Rossetti S, Aulenta F, Cruz Viggi C. Anaerobic treatment of groundwater co-contaminated by toluene and copper in a single chamber bioelectrochemical system. Bioelectrochemistry 2024; 158:108711. [PMID: 38626620 DOI: 10.1016/j.bioelechem.2024.108711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 04/10/2024] [Accepted: 04/12/2024] [Indexed: 04/18/2024]
Abstract
Addressing the simultaneous removal of multiple coexisting groundwater contaminants poses a significant challenge, primarily because of their different physicochemical properties. Indeed, different chemical compounds may necessitate establishing distinct, and sometimes conflicting, (bio)degradation and/or removal pathways. In this work, we investigated the concomitant anaerobic treatment of toluene and copper in a single-chamber bioelectrochemical cell with a potential difference of 1 V applied between the anode and the cathode. As a result, the electric current generated by the bioelectrocatalytic oxidation of toluene at the anode caused the abiotic reduction and precipitation of copper at the cathode, until the complete removal of both contaminants was achieved. Open circuit potential (OCP) experiments confirmed that the removal of copper and toluene was primarily associated with polarization. Analogously, abiotic experiments, at an applied potential of 1 V, confirmed that neither toluene was oxidized nor copper was reduced in the absence of microbial activity. At the end of each experiment, both electrodes were characterized by means of a comprehensive suite of chemical and microbiological analyses, evidencing a highly selected microbial community competent in the biodegradation of toluene in the anodic biofilm, and a uniform electrodeposition of spherical Cu2O nanoparticles over the cathode surface.
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Affiliation(s)
- Marco Resitano
- Water Research Institute (IRSA), National Research Council (CNR), 00010 Montelibretti, (RM), Italy
| | - Matteo Tucci
- Water Research Institute (IRSA), National Research Council (CNR), 00010 Montelibretti, (RM), Italy
| | - Alessio Mezzi
- Institute for the Study of Nanostructured Materials, National Research Council (CNR), 00010 Montelibretti, (RM), Italy
| | - Saulius Kaciulis
- Institute for the Study of Nanostructured Materials, National Research Council (CNR), 00010 Montelibretti, (RM), Italy
| | - Bruna Matturro
- Water Research Institute (IRSA), National Research Council (CNR), 00010 Montelibretti, (RM), Italy; National Biodiversity Future Center, Palermo 90133, Italy
| | - Emilio D'Ugo
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | | | - Stefano Fazi
- Water Research Institute (IRSA), National Research Council (CNR), 00010 Montelibretti, (RM), Italy
| | - Simona Rossetti
- Water Research Institute (IRSA), National Research Council (CNR), 00010 Montelibretti, (RM), Italy
| | - Federico Aulenta
- Water Research Institute (IRSA), National Research Council (CNR), 00010 Montelibretti, (RM), Italy; National Biodiversity Future Center, Palermo 90133, Italy
| | - Carolina Cruz Viggi
- Water Research Institute (IRSA), National Research Council (CNR), 00010 Montelibretti, (RM), Italy.
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2
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Dzofou Ngoumelah D, Heggeset TMB, Haugen T, Sulheim S, Wentzel A, Harnisch F, Kretzschmar J. Effect of model methanogens on the electrochemical activity, stability, and microbial community structure of Geobacter spp. dominated biofilm anodes. NPJ Biofilms Microbiomes 2024; 10:17. [PMID: 38443373 PMCID: PMC10915144 DOI: 10.1038/s41522-024-00490-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 02/20/2024] [Indexed: 03/07/2024] Open
Abstract
Combining anaerobic digestion (AD) and microbial electrochemical technologies (MET) in AD-MET holds great potential. Methanogens have been identified as one cause of decreased electrochemical activity and deterioration of Geobacter spp. biofilm anodes. A better understanding of the different interactions between methanogenic genera/species and Geobacter spp. biofilms is needed to shed light on the observed reduction in electrochemical activity and stability of Geobacter spp. dominated biofilms as well as observed changes in microbial communities of AD-MET. Here, we have analyzed electrochemical parameters and changes in the microbial community of Geobacter spp. biofilm anodes when exposed to three representative methanogens with different metabolic pathways, i.e., Methanosarcina barkeri, Methanobacterium formicicum, and Methanothrix soehngenii. M. barkeri negatively affected the performance and stability of Geobacter spp. biofilm anodes only in the initial batches. In contrast, M. formicicum did not affect the stability of Geobacter spp. biofilm anodes but caused a decrease in maximum current density of ~37%. M. soehngenii induced a coloration change of Geobacter spp. biofilm anodes and a decrease in the total transferred charge by ~40%. Characterization of biofilm samples after each experiment by 16S rRNA metabarcoding, whole metagenome nanopore sequencing, and shotgun sequencing showed a higher relative abundance of Geobacter spp. after exposure to M. barkeri as opposed to M. formicicum or M. soehngenii, despite the massive biofilm dispersal observed during initial exposure to M. barkeri.
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Affiliation(s)
- Daniel Dzofou Ngoumelah
- DBFZ Deutsches Biomasseforschungszentrum gemeinnützige GmbH (German Biomass Research Centre), Department of Biochemical Conversion, 04347, Leipzig, Germany
| | | | - Tone Haugen
- SINTEF Industry, Department of Biotechnology and Nanomedicine, 7034, Trondheim, Norway
| | - Snorre Sulheim
- SINTEF Industry, Department of Biotechnology and Nanomedicine, 7034, Trondheim, Norway
| | - Alexander Wentzel
- SINTEF Industry, Department of Biotechnology and Nanomedicine, 7034, Trondheim, Norway
| | - Falk Harnisch
- Helmholtz Centre for Environmental Research - UFZ, Department of Microbial Biotechnology, 04318, Leipzig, Germany
| | - Jörg Kretzschmar
- DBFZ Deutsches Biomasseforschungszentrum gemeinnützige GmbH (German Biomass Research Centre), Department of Biochemical Conversion, 04347, Leipzig, Germany.
- Zittau/Görlitz University of Applied Sciences, Faculty of Natural and Environmental Sciences, 02763, Zittau, Germany.
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3
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Dai S, Harnisch F, Morejón MC, Keller NS, Korth B, Vogt C. Microbial electricity-driven anaerobic phenol degradation in bioelectrochemical systems. ENVIRONMENTAL SCIENCE AND ECOTECHNOLOGY 2024; 17:100307. [PMID: 37593528 PMCID: PMC10432169 DOI: 10.1016/j.ese.2023.100307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 07/06/2023] [Accepted: 07/22/2023] [Indexed: 08/19/2023]
Abstract
Microbial electrochemical technologies have been extensively employed for phenol removal. Yet, previous research has yielded inconsistent results, leaving uncertainties regarding the feasibility of phenol degradation under strictly anaerobic conditions using anodes as sole terminal electron acceptors. In this study, we employed high-performance liquid chromatography and gas chromatography-mass spectrometry to investigate the anaerobic phenol degradation pathway. Our findings provide robust evidence for the purely anaerobic degradation of phenol, as we identified benzoic acid, 4-hydroxybenzoic acid, glutaric acid, and other metabolites of this pathway. Notably, no typical intermediates of the aerobic phenol degradation pathway were detected. One-chamber reactors (+0.4 V vs. SHE) exhibited a phenol removal rate of 3.5 ± 0.2 mg L-1 d-1, while two-chamber reactors showed 3.6 ± 0.1 and 2.6 ± 0.9 mg L-1 d-1 at anode potentials of +0.4 and + 0.2 V, respectively. Our results also suggest that the reactor configuration certainly influenced the microbial community, presumably leading to different ratios of phenol consumers and microorganisms feeding on degradation products.
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Affiliation(s)
- Shixiang Dai
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Germany
| | - Falk Harnisch
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Germany
| | - Micjel Chávez Morejón
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Germany
| | - Nina Sophie Keller
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Germany
| | - Benjamin Korth
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Germany
| | - Carsten Vogt
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Germany
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4
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Korth B, Pereira J, Sleutels T, Harnisch F, Heijne AT. Comparing theoretical and practical biomass yields calls for revisiting thermodynamic growth models for electroactive microorganisms. WATER RESEARCH 2023; 242:120279. [PMID: 37451189 DOI: 10.1016/j.watres.2023.120279] [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: 11/10/2022] [Revised: 06/12/2023] [Accepted: 06/26/2023] [Indexed: 07/18/2023]
Abstract
Research on electroactive microorganisms (EAM) often focuses either on their physiology and the underlying mechanisms of extracellular electron transfer or on their application in microbial electrochemical technologies (MET). Thermodynamic understanding of energy conversions related to growth and activity of EAM has received only a little attention. In this study, we aimed to prove the hypothesized restricted energy harvest of EAM by determining biomass yields by monitoring growth of acetate-fed biofilms presumably enriched in Geobacter, using optical coherence tomography, at three anode potentials and four acetate concentrations. Experiments were concurrently simulated using a refined thermodynamic model for EAM. Neither clear correlations were observed between biomass yield and anode potential nor acetate concentration, albeit the statistical significances are limited, mainly due to the observed experimental variances. The experimental biomass yield based on acetate consumption (YX/ac = 37 ± 9 mgCODbiomass gCODac-1) was higher than estimated by modeling, indicating limitations of existing growth models to predict yields of EAM. In contrast, the modeled biomass yield based on catabolic energy harvest was higher than the biomass yield from experimental data (YX/cat = 25.9 ± 6.8 mgCODbiomass kJ-1), supporting restricted energy harvest of EAM and indicating a role of not considered energy sinks. This calls for an adjusted growth model for EAM, including, e.g., the microbial electrochemical Peltier heat to improve the understanding and modeling of their energy metabolism. Furthermore, the reported biomass yields are important parameters to design strategies for influencing the interactions between EAM and other microorganisms and allowing more realistic feasibility assessments of MET.
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Affiliation(s)
- Benjamin Korth
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research GmbH - UFZ, Permoserstr. 15, Leipzig 04318, Germany.
| | - João Pereira
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9 8911, MA, Leeuwarden, The Netherlands; Environmental Technology, Wageningen University, Bornse Weilanden 9, P.O. Box 17 6700 AA, Wageningen, The Netherlands
| | - Tom Sleutels
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9 8911, MA, Leeuwarden, The Netherlands; Faculty of Science and Engineering, University of Groningen, Nijenborgh 4 9747 AG, Groningen, The Netherlands
| | - Falk Harnisch
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research GmbH - UFZ, Permoserstr. 15, Leipzig 04318, Germany
| | - Annemiek Ter Heijne
- Environmental Technology, Wageningen University, Bornse Weilanden 9, P.O. Box 17 6700 AA, Wageningen, The Netherlands
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5
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Dzofou Ngoumelah D, Kuchenbuch A, Harnisch F, Kretzschmar J. Combining Geobacter spp. Dominated Biofilms and Anaerobic Digestion Effluents─The Effect of Effluent Composition and Electrode Potential on Biofilm Activity and Stability. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:2584-2594. [PMID: 36731122 DOI: 10.1021/acs.est.2c07574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The combination of anaerobic digestion (AD) and microbial electrochemical technologies (METs) offers different opportunities to increase the efficiency and sustainability of AD processes. However, methanogenic archaea and/or particles may partially hinder combining MET and AD processes. Furthermore, it is unclear if the applied anode potential affects the activity and efficiency of electroactive microorganisms in AD-MET combinations as it is described for more controlled experimental conditions. In this study, we confirm that 6-week-old Geobacter spp. dominated biofilms are by far more active and stable in AD-effluents than 3-week-old Geobacter spp. dominated biofilms. Furthermore, we show that the biofilms are twice as active at -0.2 V compared to 0.4 V, even under challenging conditions occurring in AD-MET systems. Paired-end amplicon sequencing at the DNA level using 16S-rRNA and mcrA gene shows that hydrogenotrophic methanogens incorporate into biofilms immersed in AD-effluent without any negative effect on biofilm stability and electrochemical activity.
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Affiliation(s)
- Daniel Dzofou Ngoumelah
- Department of Biochemical Conversion, DBFZ Deutsches Biomasseforschungszentrum gemeinnützige GmbH (German Biomass Research Centre), Leipzig04347, Saxony, Germany
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Leipzig04318, Saxony, Germany
| | - Anne Kuchenbuch
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Leipzig04318, Saxony, Germany
| | - Falk Harnisch
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Leipzig04318, Saxony, Germany
| | - Jörg Kretzschmar
- Department of Biochemical Conversion, DBFZ Deutsches Biomasseforschungszentrum gemeinnützige GmbH (German Biomass Research Centre), Leipzig04347, Saxony, Germany
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6
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Kubannek F, Block J, Munirathinam B, Krull R. Reaction kinetics of anodic biofilms under changing substrate concentrations: Uncovering shifts in Nernst‐Monod curves via substrate pulses. Eng Life Sci 2022; 22:152-164. [PMID: 35382544 PMCID: PMC8961052 DOI: 10.1002/elsc.202100088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 11/14/2021] [Accepted: 12/19/2021] [Indexed: 11/25/2022] Open
Abstract
In the present study, it is shown that the concentration dependency of undefined mixed culture anodic biofilms does not follow a single kinetic curve, such as the Nernst‐Monod curve. The biofilms adapt to concentration changes, which inevitably have to be applied to record kinetic curves, resulting in strong shifts of the kinetic parameters. The substrate concentration in a continuously operated bioelectrochemical system was changed rapidly via acetate pulses to record Nernst‐Monod curves which are not influenced by biofilm adaptation processes. The values of the maximum current density jmax and apparent half‐saturation rate constant Ks increased from 0.5 to 1 mA cm−2 and from 0.5 to 1.6 mmol L−1, respectively, within approximately 5 h. Double pulse experiments with a starvation phase between the two acetate pulses showed that jmax and Ks decrease reversibly through an adaptation process when no acetate is available. Pseudo‐capacitive charge values estimated from non‐turnover cyclic voltammograms (CV) led to the hypothesis that biofilm adaptation and the observed shift of the Nernst‐Monod curves occurred due to changes in the concentration of active redox proteins in the biofilm. It is argued that concentration‐related parameters of kinetic models for electroactive biofilms are only valid for the operating points where they have been determined and should always be reported with those conditions.
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Affiliation(s)
- Fabian Kubannek
- Institute of Energy and Process Systems Engineering Technische Universität Braunschweig Braunschweig Germany
| | - Jonathan Block
- Institute of Biochemical Engineering Technische Universität Braunschweig Braunschweig Germany
| | - Balakrishnan Munirathinam
- Institute of Energy and Process Systems Engineering Technische Universität Braunschweig Braunschweig Germany
| | - Rainer Krull
- Institute of Biochemical Engineering Technische Universität Braunschweig Braunschweig Germany
- Center of Pharmaceutical Engineering (PVZ) Technische Universität Braunschweig Braunschweig Germany
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7
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Scarabotti F, Bühler K, Schmidt M, Harnisch F. Thickness and roughness of transparent gold-palladium anodes have no impact on growth kinetics and yield coefficients of early-stage Geobacter sulfurreducens biofilms. Bioelectrochemistry 2021; 144:108043. [PMID: 34959027 DOI: 10.1016/j.bioelechem.2021.108043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 11/24/2021] [Accepted: 12/13/2021] [Indexed: 01/05/2023]
Abstract
Geobacter sulfurreducens is the model organism for electroactive microorganisms performing direct extracellular electron transfer and forming thick mature biofilm electrodes. Although numerous physiological properties of mature biofilm electrodes are deciphered, there is an extensive gap of knowledge on the early-stage biofilm formation. We have shown recently that transparent gold-palladium (AuPd) electrodes allow for analysis of early-stage biofilm formation using confocal laser scanning microscopy. Here we analysed the influence of thickness (ranging from 12.5 to 200 nm) and roughness of AuPd electrodes on physiological parameters of G. sulfurreducens early-stage biofilms. We show that when grown potentiostatically at -200 mV vs. Ag/ AgCl sat. KCl neither maximum current density (jmax of ∼ 80-150 µA cm-2) nor lag time (lag t of ∼ 0.2-0.4 days) or single cell yield coefficients (YNe of 1.43 × 1012 cells mole--1) of the biofilms are influenced by the electrode preparation. This confirms the robustness of the experimental approach, which is an inevitable prerequisite for obtaining reliable results in follow-up experiments.
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Affiliation(s)
- Francesco Scarabotti
- Department of Environmental Microbiology, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Katja Bühler
- Department Solar Materials, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Matthias Schmidt
- Department of Isotope Biogeochemistry, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Falk Harnisch
- Department of Environmental Microbiology, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany.
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8
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Simultaneous removal of hydrocarbons and sulfate from groundwater using a “bioelectric well”. Electrochim Acta 2021. [DOI: 10.1016/j.electacta.2021.138636] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Dzofou Ngoumelah D, Harnisch F, Kretzschmar J. Benefits of Age-Improved Resistance of Mature Electroactive Biofilm Anodes in Anaerobic Digestion. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:8258-8266. [PMID: 34096274 DOI: 10.1021/acs.est.0c07320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Anaerobic digestion (AD) and microbial electrochemical technologies (MET) can be combined in manifold ways. Recent studies show negative influences of AD effluents on the performance of pre-grown Geobacter spp.-dominated biofilm anodes. In this study, it was investigated how such biofilm anodes are affected by AD effluents. Therefore, experiments using AD effluents in different concentrations (0-100%) in combination with biofilms of different ages were performed. Furthermore, the activity of methanogens was inhibited and minimized by application of 2-bromoethanesulfonate (2-BES) and microfiltration, respectively. Biofilms pre-grown for 5 weeks show higher resistance against AD effluents compared to biofilms pre-grown for only 3 weeks. Nevertheless, adaptation of biofilms to AD effluents was not successful. Biofilm activity in terms of coulombic efficiency and maximum current density (jmax) dropped by factor 32.2 ± 3.2 and 38.9 ± 8.4, respectively. The application of 2-BES and microfiltration had positive effects on the biofilm activity. The results support the assumption that methanogens or further compounds not studied here, for example, protozoans, which may have been inhibited or removed by 2-BES application or microfiltration, have an immediate influence on the stability of Geobacter spp.-dominated biofilms and may limit their practical application in AD environments.
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Affiliation(s)
- Daniel Dzofou Ngoumelah
- Biochemical Conversion Department, DBFZ Deutsches Biomasseforschungszentrum gemeinnützige GmbH (German Biomass Research Centre), Torgauer Straße 116, 04347 Leipzig, Germany
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, 04318 Leipzig, Germany
| | - Falk Harnisch
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, 04318 Leipzig, Germany
| | - Jörg Kretzschmar
- Biochemical Conversion Department, DBFZ Deutsches Biomasseforschungszentrum gemeinnützige GmbH (German Biomass Research Centre), Torgauer Straße 116, 04347 Leipzig, Germany
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10
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Impact of Surface Properties of Porous SiOC‐Based Materials on the Performance of
Geobacter
Biofilm Anodes. ChemElectroChem 2021. [DOI: 10.1002/celc.202001568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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11
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Quejigo JR, Korth B, Kuchenbuch A, Harnisch F. Redox Potential Heterogeneity in Fixed-Bed Electrodes Leads to Microbial Stratification and Inhomogeneous Performance. CHEMSUSCHEM 2021; 14:1155-1165. [PMID: 33387375 PMCID: PMC7986606 DOI: 10.1002/cssc.202002611] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 12/28/2020] [Indexed: 06/12/2023]
Abstract
Bed electrodes provide high electrode area-to-volume ratios represent a promising configuration for transferring bioelectrochemical systems close to industrial applications. Nevertheless, the intrinsic electrical resistance leads to poor polarization behavior. Therefore, the distribution of Geobacter spp. and their electrochemical performance within exemplary fixed-bed electrodes are investigated. A minimally invasive sampling system allows characterization of granules from different spatial locations of bed electrodes. Cyclic voltammetry of single granules (n=63) demonstrates that the major share of electroactivity (134.3 mA L-1 ) is achieved by approximately 10 % of the bed volume, specifically that being close to the current collector. Nevertheless, analysis of the microbial community reveals that Geobacter spp. dominated all sampled granules. These findings clearly demonstrate the need for engineered bed electrodes to improve electron exchange between microorganisms and granules.
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Affiliation(s)
- Jose Rodrigo Quejigo
- Department of Environmental MicrobiologyHelmholtz Centre for Environmental Research GmbH – UFZPermoser Str. 1504318LeipzigGermany
| | - Benjamin Korth
- Department of Environmental MicrobiologyHelmholtz Centre for Environmental Research GmbH – UFZPermoser Str. 1504318LeipzigGermany
| | - Anne Kuchenbuch
- Department of Environmental MicrobiologyHelmholtz Centre for Environmental Research GmbH – UFZPermoser Str. 1504318LeipzigGermany
| | - Falk Harnisch
- Department of Environmental MicrobiologyHelmholtz Centre for Environmental Research GmbH – UFZPermoser Str. 1504318LeipzigGermany
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12
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Scarabotti F, Rago L, Bühler K, Harnisch F. The electrode potential determines the yield coefficients of early-stage Geobacter sulfurreducens biofilm anodes. Bioelectrochemistry 2021; 140:107752. [PMID: 33618189 DOI: 10.1016/j.bioelechem.2021.107752] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/29/2021] [Accepted: 01/30/2021] [Indexed: 01/05/2023]
Abstract
Geobacter sulfurreducens is the model for electroactive microorganisms (EAM). EAM can use solid state terminal electron acceptors (TEA) including anodes via extracellular electron transfer (EET). Yield coefficients relate the produced cell number or biomass to the oxidized substrate or the reduced TEA. These data are not yet sufficiently available for EAM growing at anodes. Thus, this study provides information about kinetics as well as yield coefficients of early-stage G. sulfurreducens biofilms using anodes as TEA at the potentials of -200 mV, 0 mV and +200 mV (vs. Ag/AgCl sat. KCl). The selected microorganism was therefore cultivated in single and double chamber batch reactors on graphite or AuPd anodes. Interestingly, whereas the lag time and maximum current density within 12 days of growth differed, the anode potential does not influence the coulombic efficiency and the formal potential of the EET, which remains constant for all the experiments at ~ -300 to -350 mV. We demonstrated for the first time that the anode potential has a strong influence on single cell yield coefficients which ranged from 2.69 × 1012 cells mole--1 at -200 mV and 1.48 × 1012 cells mole--1 at 0 mV to 2.58 × 1011 cells mole--1 at +200 mV in single chamber reactors and from 1.15 × 1012 cells mole--1 at -200 mV to 8.98× 1011 cells mole--1 at 0 mV in double chamber reactors. This data can be useful for optimization and scaling-up of primary microbial electrochemical technologies.
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Affiliation(s)
- Francesco Scarabotti
- Department of Environmental Microbiology, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Laura Rago
- Department of Environmental Microbiology, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Katja Bühler
- Department Solar Materials, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Falk Harnisch
- Department of Environmental Microbiology, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany.
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13
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Guo Y, Rosa LF, Müller S, Harnisch F. Monitoring stratification of anode biofilms in bioelectrochemical laminar flow reactors using flow cytometry. ENVIRONMENTAL SCIENCE AND ECOTECHNOLOGY 2020; 4:100062. [PMID: 36157706 PMCID: PMC9488081 DOI: 10.1016/j.ese.2020.100062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/25/2020] [Accepted: 09/26/2020] [Indexed: 06/16/2023]
Abstract
A laminar flow bioelectrochemical systems (BES) was designed and benchmarked using microbial anodes dominated with Geobacter spp. The reactor architecture was based on modeled flow fields, the resulting structure was 3D printed and used for BES manufacturing. Stratification of the substrate availability within the reactor channels led to heterogeneous biomass distribution, with the maximum biomass found mainly in the initial/middle channels. The anode performance was assessed for different hydraulic retention times while coulombic efficiencies of up to 100% (including also hydrogen recycling from the cathode) and current densities of up to 75 μA cm-2 at an anode surface to volume ratio of 1770 cm2 L-1 after 35 days were achieved. This low current density can be clearly attributed to the heterogeneous distributions of biomass and the stratification of the microbial community structure. Further, it was shown that time and space resolved analysis of the reactor microbiomes per channel is feasible using flow cytometry.
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