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Fessler M, Madsen JS, Zhang Y. Microbial Interactions in Electroactive Biofilms for Environmental Engineering Applications: A Role for Nonexoelectrogens. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:15273-15279. [PMID: 36223388 DOI: 10.1021/acs.est.2c04368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Microbial electrochemical systems have gained much attention over the past decade due to their potential for various environmental engineering applications ranging from energy production to wastewater treatment to bioproduction. At the heart of these systems lie exoelectrogens-microorganisms capable of exporting electrons generated during metabolism to external electron acceptors such as electrodes. The bacterial biofilm communities on these electrodes are dominated by exoelectrogens but are nonetheless extremely diverse. So far, within the field, the main focus has been on the electroactive bacteria. However, to broaden our understanding of these communities, it is crucial to clarify how the remaining inhabitants of electrode-respiring biofilms contribute to the overall function of the biofilm. Ultimately, such insights may enable improvement of microbial electrochemical systems by reshaping the community structure with naturally occurring beneficial strains.
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Affiliation(s)
- Mathias Fessler
- Department of Environmental and Resource Engineering, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Jonas Stenløkke Madsen
- Section of Microbiology, Department of Biology, University of Copenhagen, 2100 Copenhagen Ø, Denmark
| | - Yifeng Zhang
- Department of Environmental and Resource Engineering, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
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2
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Zakaria BS, Guo H, Kim Y, Dhar BR. Molecular biology and modeling analysis reveal functional roles of propionate to acetate ratios on microbial syntrophy and competition in electro-assisted anaerobic digestion. WATER RESEARCH 2022; 216:118335. [PMID: 35358877 DOI: 10.1016/j.watres.2022.118335] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 03/08/2022] [Accepted: 03/19/2022] [Indexed: 06/14/2023]
Abstract
This study examined the significance of propionate to acetate (HPr/HAc) ratios on microbial syntrophy and competition in microbial electrolysis cell-assisted anaerobic digestion (MEC-AD). In addition to molecular biology and phylogenetic analysis, a numerical MEC-AD model was developed by modifying Anaerobic Digestion Model No.1 to predict the effects of different HPr/HAc ratios (0.5, 1.5, 2.5, and 5). The HPr/HAc ratios of 0.5 and 1.5 maintained efficient syntrophy among electroactive bacteria, hydrogenotrophic methanogens, and homoacetogens, leading to higher methane yields. In contrast, higher HPr/HAc ratios of 2.5 and 5 were detrimental to methanogenesis. Both microbial community analysis and numerical modeling results suggested that higher propionate levels could promote the enrichment of H2-utilizing acetogens, thereby triggering their competition with hydrogenotrophic methanogens. Moreover, protein fraction in extracellular polymeric substances and the relative expression of genes associated with extracellular electron transfer in both anode and cathode biofilms were markedly decreased with increasing HPr/HAc ratios, indicating partial inhibition of microbial electroactivity. Overall, these results illuminate deep insight into anaerobic syntrophy, contributing to the process kinetics and methane yields in MEC-AD systems. Furthermore, from a practical viewpoint, the results can also be helpful in effective control of MEC-AD operation without propionate accumulation.
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Affiliation(s)
- Basem S Zakaria
- Civil and Environmental Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
| | - Hui Guo
- Civil Engineering, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Younggy Kim
- Civil Engineering, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Bipro Ranjan Dhar
- Civil and Environmental Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.
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3
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Gong L, Abbaszadeh Amirdehi M, Sonawane JM, Jia N, Torres de Oliveira L, Greener J. Mainstreaming microfluidic microbial fuel cells: a biocompatible membrane grown in situ improves performance and versatility. LAB ON A CHIP 2022; 22:1905-1916. [PMID: 35441185 DOI: 10.1039/d2lc00098a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
A recent trend in microfluidic microbial fuel cells (MFCs) is to exclude a separation membrane, instead, relying on the physics of laminar flow to maintain isolation between anode and cathode compartments. To avoid solution crossover, the electrodes may be separated by distances of several millimeters, but this negatively affects the internal resistance and undermines a prime advantage of microscale MFCs. Therefore, we propose a facile method for in situ synthesis of a micromembrane that supports sub-millimeter electrode spacing. Membrane synthesis in situ reduces device fabrication complexity, and the proposed design avoids electrode contamination during its synthesis. Comparing results to a state-of-the-art membraneless MFC with 6 mm inter-electrode distances, the sub-millimeter membrane MFC under comparable flow conditions had an internal resistance that was 60% lower, power and current densities that were respectively 45% and 290% higher, and acetate conversion efficiencies that were 8 times higher. The enhanced flow stability provided stable operation under imbalanced flow conditions and delivered continuous increases to power density of up to 30% for flow rate increases of 100 times over baseline levels. As a result, maximum outputs obtained were 660 mW m-1 and 3.5 A m-1. These are the highest reported for microfluidic MFCs using pure culture bacteria, which advances the goal of competing with mainstream MFC formats.
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Affiliation(s)
- Lingling Gong
- Département de chimie, Faculté des sciences et de génie, Université Laval, Québec G1V 0A6, Canada.
| | | | - Jayesh M Sonawane
- Département de chimie, Faculté des sciences et de génie, Université Laval, Québec G1V 0A6, Canada.
| | - Nan Jia
- Département de chimie, Faculté des sciences et de génie, Université Laval, Québec G1V 0A6, Canada.
| | - Leon Torres de Oliveira
- Département de chimie, Faculté des sciences et de génie, Université Laval, Québec G1V 0A6, Canada.
| | - Jesse Greener
- Département de chimie, Faculté des sciences et de génie, Université Laval, Québec G1V 0A6, Canada.
- CHU de Québec, Université Laval, Québec G1L 3L5, Canada
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4
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Wang XT, Zhang YF, Wang B, Wang S, Xing X, Xu XJ, Liu WZ, Ren NQ, Lee DJ, Chen C. Enhancement of methane production from waste activated sludge using hybrid microbial electrolysis cells-anaerobic digestion (MEC-AD) process - A review. BIORESOURCE TECHNOLOGY 2022; 346:126641. [PMID: 34973405 DOI: 10.1016/j.biortech.2021.126641] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 12/22/2021] [Accepted: 12/24/2021] [Indexed: 06/14/2023]
Abstract
Hybrid microbial electrolysis cells-anaerobic digestion (MEC-AD) was proved to increase methane productivity and methane yield of waste activated sludge (WAS) by establishing direct interspecies electron transfer method and enriching functional microorganisms. This review first summarized the pretreatment methods of WAS for MEC-AD and then reviewed the reactor configurations, operation parameters, and the economic benefit of MEC-AD. Furthermore, the enhancement mechanisms of MEC-AD were reviewed based on the analysis of thermodynamics and microbial community. It was found that the decrease of hydrogen partial pressure due to the hydrogenotrophic methanogens enriched in cathodic biofilm and direct interspecies electron transfer between exoelectrogens and anode were the core mechanisms for improving acidogenesis, acetogenesis, and methanogenesis. Finally, the potentially technological issues that need to be addressed to increase energy efficiency in large-scale MEC-AD processes were discussed.
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Affiliation(s)
- Xue-Ting Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China; Department of Environmental Engineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Yi-Feng Zhang
- Department of Environmental Engineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Bo Wang
- Department of Environmental Engineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Song Wang
- Department of Environmental Engineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Xue Xing
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China
| | - Xi-Jun Xu
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China
| | - Wen-Zong Liu
- School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China
| | - Nan-Qi Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China
| | - Duu-Jong Lee
- Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan
| | - Chuan Chen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China.
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5
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Wang H, Liu Y, Du H, Zhu J, Peng L, Yang C, Luo F. Exploring the effect of voltage on biogas production performance and the methanogenic pathway of microbial electrosynthesis. Biochem Eng J 2021. [DOI: 10.1016/j.bej.2021.108028] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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6
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Yan X, Wang B, Liang H, Yang J, Zhao J, Ndayisenga F, Zhang H, Yu Z, Qian Z. Enhanced straw fermentation process based on microbial electrolysis cell coupled anaerobic digestion. Chin J Chem Eng 2021. [DOI: 10.1016/j.cjche.2021.05.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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7
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Sapireddy V, Katuri KP, Muhammad A, Saikaly PE. Competition of two highly specialized and efficient acetoclastic electroactive bacteria for acetate in biofilm anode of microbial electrolysis cell. NPJ Biofilms Microbiomes 2021; 7:47. [PMID: 34059681 PMCID: PMC8166840 DOI: 10.1038/s41522-021-00218-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 04/07/2021] [Indexed: 02/04/2023] Open
Abstract
Maintaining functional stability of microbial electrolysis cell (MEC) treating wastewater depends on maintaining functional redundancy of efficient electroactive bacteria (EAB) on the anode biofilm. Therefore, investigating whether efficient EAB competing for the same resources (electron donor and acceptor) co-exist at the anode biofilm is key for the successful application of MEC for wastewater treatment. Here, we compare the electrochemical and kinetic properties of two efficient acetoclastic EAB, Geobacter sulfurreducens (GS) and Desulfuromonas acetexigens (DA), grown as monoculture in MECs fed with acetate. Additionally, we monitor the evolution of DA and GS in co-culture MECs fed with acetate or domestic wastewater using fluorescent in situ hybridization. The apparent Monod kinetic parameters reveal that DA possesses higher jmax (10.7 ± 0.4 A/m2) and lower KS, app (2 ± 0.15 mM) compared to GS biofilms (jmax: 9.6 ± 0.2 A/m2 and KS, app: 2.9 ± 0.2 mM). Further, more donor electrons are diverted to the anode for respiration in DA compared to GS. In acetate-fed co-culture MECs, DA (98% abundance) outcompete GS for anode-dependent growth. In contrast, both EAB co-exist (DA: 55 ± 2%; GS: 24 ± 1.1%) in wastewater-fed co-culture MECs despite the advantage of DA over GS based on kinetic parameters alone. The co-existence of efficient acetoclastic EAB with high current density in MECs fed with wastewater is significant in the context of functional redundancy to maintain stable performance. Our findings also provide insight to future studies on bioaugmentation of wastewater-fed MECs with efficient EAB to enhance performance.
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Affiliation(s)
- Veerraghavulu Sapireddy
- Biological and Environmental Science and Engineering Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Krishna P Katuri
- Biological and Environmental Science and Engineering Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
| | - Ali Muhammad
- Biological and Environmental Science and Engineering Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Pascal E Saikaly
- Biological and Environmental Science and Engineering Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
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8
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9
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Ragab A, Shaw DR, Katuri KP, Saikaly PE. Effects of set cathode potentials on microbial electrosynthesis system performance and biocathode methanogen function at a metatranscriptional level. Sci Rep 2020; 10:19824. [PMID: 33188217 PMCID: PMC7666199 DOI: 10.1038/s41598-020-76229-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 10/12/2020] [Indexed: 11/09/2022] Open
Abstract
Microbial electrosynthesis exploits the catalytic activity of microorganisms to utilize a cathode as an electron donor for reducing waste CO2 to valuable fuels and chemicals. Electromethanogenesis is the process of CO2 reduction to CH4 catalyzed by methanogens using the cathode directly as a source of electrons or indirectly via H2. Understanding the effects of different set cathode potentials on the functional dynamics of electromethanogenic communities is crucial for the rational design of cathode materials. Replicate enriched electromethanogenic communities were subjected to different potentials (- 1.0 V and - 0.7 V vs. Ag/AgCl) and the potential-induced changes were analyzed using a metagenomic and metatranscriptomic approach. The most abundant and transcriptionally active organism on the biocathodes was a novel species of Methanobacterium sp. strain 34x. The cathode potential-induced changes limited electron donor availability and negatively affected the overall performance of the reactors in terms of CH4 production. Although high expression of key genes within the methane and carbon metabolism pathways was evident, there was no significant difference in transcriptional response to the different set potentials. The acetyl-CoA decarbonylase/synthase (ACDS) complex were the most highly expressed genes, highlighting the significance of carbon assimilation under limited electron donor conditions and its link to the methanogenesis pathway.
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Affiliation(s)
- Ala'a Ragab
- Biological and Environmental Science and Engineering Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Dario Rangel Shaw
- Biological and Environmental Science and Engineering Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Krishna P Katuri
- Biological and Environmental Science and Engineering Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Pascal E Saikaly
- Biological and Environmental Science and Engineering Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.
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10
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Flores-Rodriguez C, Min B. Enrichment of specific microbial communities by optimum applied voltages for enhanced methane production by microbial electrosynthesis in anaerobic digestion. BIORESOURCE TECHNOLOGY 2020; 300:122624. [PMID: 31918296 DOI: 10.1016/j.biortech.2019.122624] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 12/10/2019] [Accepted: 12/12/2019] [Indexed: 06/10/2023]
Abstract
This study investigates the distribution of microbiome in microbial electrosynthesis systems at different applied voltages (0.5, 1.0, and 1.5 V) for methane production. Results revealed that more favorable conditions for methane production were observed with 1.0 V applied voltage. In Venn plots, the bioelectrodes at 1.0 V had higher numbers of unique operational taxonomic units compared to those at 0.5 and 1.5 V. Hierarchical cluster, non-metric multidimensional scaling, and principal component ordinate analyses revealed that the biocathode at 1.0 V clustered separately from the rest of the biofilms mainly because of the quantitative differences in the microbial distribution. Taxonomically, exoelectrogens (Geobacter spp.) dominated the bioanode at 1.0 V, while the syntrophic assemblages of hydrogen-producing bacteria (i.e., Bacteroidetes and Firmicutes) and hydrogen-consuming methanogens (i.e., Methanobacterium sp.) existed in the biocathode. These results suggest that the optimum applied voltage enriched specific microbial communities on the anode and cathode for enhanced methane production.
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Affiliation(s)
- Carla Flores-Rodriguez
- Department of Environmental Science and Engineering, Kyung Hee University, Seocheon-dong, Yongin-si, Gyeonggi-do 446-701, Republic of Korea
| | - Booki Min
- Department of Environmental Science and Engineering, Kyung Hee University, Seocheon-dong, Yongin-si, Gyeonggi-do 446-701, Republic of Korea.
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11
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Enhanced CO2 Conversion to Acetate through Microbial Electrosynthesis (MES) by Continuous Headspace Gas Recirculation. ENERGIES 2019. [DOI: 10.3390/en12173297] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Bioelectrochemical systems (BESs) is a term that encompasses a group of novel technologies able to interconvert electrical energy and chemical energy by means of a bioelectroactive biofilm. Microbial electrosynthesis (MES) systems, which branch off from BESs, are able to convert CO2 into valuable organic chemicals and fuels. This study demonstrates that CO2 reduction in MES systems can be enhanced by enriching the inoculum and improving CO2 availability to the biofilm. The proposed system is proven to be a repetitive, efficient, and selective way of consuming CO2 for the production of acetic acid, showing cathodic efficiencies of over 55% and CO2 conversions of over 80%. Continuous recirculation of the gas headspace through the catholyte allowed for a 44% improvement in performance, achieving CO2 fixation rates of 171 mL CO2 L−1·d−1, a maximum daily acetate production rate of 261 mg HAc·L−1·d−1, and a maximum acetate titer of 1957 mg·L−1. High-throughput sequencing revealed that CO2 reduction was mainly driven by a mixed-culture biocathode, in which Sporomusa and Clostridium, both bioelectrochemical acetogenic bacteria, were identified together with other species such as Desulfovibrio, Pseudomonas, Arcobacter, Acinetobacter or Sulfurospirillum, which are usually found in cathodic biofilms. Moreover, results suggest that these communities are responsible of maintaining a stable reactor performance.
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12
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Ragab A, Katuri KP, Ali M, Saikaly PE. Evidence of Spatial Homogeneity in an Electromethanogenic Cathodic Microbial Community. Front Microbiol 2019; 10:1747. [PMID: 31417533 PMCID: PMC6685142 DOI: 10.3389/fmicb.2019.01747] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 07/15/2019] [Indexed: 11/17/2022] Open
Abstract
Microbial electrosynthesis (MES) has been gaining considerable interest as the next step in the evolution of microbial electrochemical technologies. Understanding the niche biocathode environment and microbial community is critical for further developing this technology as the biocathode is key to product formation and efficiency. MES is generally operated to enrich a specific functional group (e.g., methanogens or homoacetogens) from a mixed-culture inoculum. However, due to differences in H2 and CO2 availability across the cathode surface, competition and syntrophy may lead to overall variability and significant beta-diversity within and between replicate reactors, which can affect performance reproducibility. Therefore, this study aimed to investigate the distribution and potential spatial variability of the microbial communities in MES methanogenic biocathodes. Triplicate methanogenic biocathodes were enriched in microbial electrolysis cells for 5 months at an applied voltage of 0.7 V. They were then transferred to triplicate dual-chambered MES reactors and operated at -1.0 V vs. Ag/AgCl for six batches. At the end of the experiment, triplicate samples were taken at different positions (top, center, bottom) from each biocathode for a total of nine samples for total biomass protein analysis and 16S rRNA gene amplicon sequencing. Microbial community analyses showed that the biocathodes were highly enriched with methanogens, especially the hydrogenotrophic methanogen family Methanobacteriaceae, Methanobacterium sp., and the mixotrophic Methanosarcina sp., with an overall core community representing > 97% of sequence reads in all samples. There was no statistically significant spatial variability (p > 0.05) observed in the distribution of these communities within and between the reactors. These results suggest deterministic community assembly and indicate the reproducibility of electromethanogenic biocathode communities, with implications for larger-scale reactors.
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Affiliation(s)
- Ala'a Ragab
- Biological and Environmental Science and Engineering Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Krishna P Katuri
- Biological and Environmental Science and Engineering Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Muhammad Ali
- Biological and Environmental Science and Engineering Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Pascal E Saikaly
- Biological and Environmental Science and Engineering Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
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13
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The role of microbial electrolysis cell in urban wastewater treatment: integration options, challenges, and prospects. Curr Opin Biotechnol 2019; 57:101-110. [DOI: 10.1016/j.copbio.2019.03.007] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 12/07/2018] [Accepted: 03/05/2019] [Indexed: 01/08/2023]
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14
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Effect of specific cathode surface area on biofouling in an anaerobic electrochemical membrane bioreactor: Novel insights using high-speed video camera. J Memb Sci 2019. [DOI: 10.1016/j.memsci.2019.02.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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15
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Yang J, Cheng S, Li C, Sun Y, Huang H. Shear Stress Affects Biofilm Structure and Consequently Current Generation of Bioanode in Microbial Electrochemical Systems (MESs). Front Microbiol 2019; 10:398. [PMID: 30894842 PMCID: PMC6415583 DOI: 10.3389/fmicb.2019.00398] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 02/15/2019] [Indexed: 12/02/2022] Open
Abstract
Shear stress is an important factor that affects the formation and structure of anode biofilms, which are strongly related to the extracellular electron transfer phenomena and bioelectric performance of bioanodes. Here, we show that using nitrogen sparging to induce shear stress during anode biofilm formation increases the linear sweep voltammetry peak current density of the mature anode biofilm from 2.37 ± 0.15 to 4.05 ± 0.25 A/m2. Electrochemical impedance spectroscopy results revealed that the shear-stress-enriched anode biofilm had a low charge transfer resistance of 46.34 Ω compared to that of the unperturbed enriched anode biofilm (72.2 Ω). Confocal laser scanning microscopy observations showed that the shear-stress-enriched biofilms were entirely viable, whereas the unperturbed enriched anode biofilm consisted of a live outer layer covering a dead inner-core layer. Based on biomass and community analyses, the shear-stress-enriched biofilm had four times the biofilm density (136.0 vs. 27.50 μg DNA/cm3) and twice the relative abundance of Geobacteraceae (over 80 vs. 40%) in comparison with those of the unperturbed enriched anode biofilm. These results show that applying high shear stress during anode biofilm enrichment can result in an entirely viable and dense biofilm with a high relative abundance of exoelectrogens and, consequently, better performance.
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Affiliation(s)
- Jiawei Yang
- State Key Laboratory of Clean Energy, Department of Energy Engineering, Zhejiang University, Hangzhou, China
| | - Shaoan Cheng
- State Key Laboratory of Clean Energy, Department of Energy Engineering, Zhejiang University, Hangzhou, China
| | - Chaochao Li
- State Key Laboratory of Clean Energy, Department of Energy Engineering, Zhejiang University, Hangzhou, China
| | - Yi Sun
- State Key Laboratory of Clean Energy, Department of Energy Engineering, Zhejiang University, Hangzhou, China
| | - Haobin Huang
- State Key Laboratory of Clean Energy, Department of Energy Engineering, Zhejiang University, Hangzhou, China
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16
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Gustave W, Yuan ZF, Sekar R, Toppin V, Liu JY, Ren YX, Zhang J, Chen Z. Relic DNA does not obscure the microbial community of paddy soil microbial fuel cells. Res Microbiol 2019; 170:97-104. [DOI: 10.1016/j.resmic.2018.11.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 10/11/2018] [Accepted: 11/14/2018] [Indexed: 10/27/2022]
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17
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Toczyłowska-Mamińska R, Szymona K, Kloch M. Bioelectricity production from wood hydrothermal-treatment wastewater: Enhanced power generation in MFC-fed mixed wastewaters. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 634:586-594. [PMID: 29635201 DOI: 10.1016/j.scitotenv.2018.04.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 04/01/2018] [Accepted: 04/02/2018] [Indexed: 06/08/2023]
Abstract
Electrogenic microorganisms are the heart of microbial fuel cell (MFC) systems that enable the conversion of waste into bioelectricity. Bacteria able to generate current, found in various natural and anthropogenic environments, need simple substrates such as acetate or glucose. Complex substrates are utilized by bacterial consortia made up of strains that exhibit a wide range of enzymatic and metabolic activity that determines the type of substrate they are able to degrade. The characteristics of the environment that a bacterial consortium develops in strongly affect the consortium's species composition and electrogenic potential. This study presents the first attempt to use industrial raw wastewater from the hydrothermal treatment of wood (WHTW) as a substrate and a source of bacterial consortia for MFC, so that such wastewater could simultaneously be treated and produce bioelectricity. The power generated in MFCs fed with WHTW was enhanced remarkably from 70 to 360mW/m2 when municipal wastewater was introduced into the reactor. An analysis of the bacterial composition of these two types of wastewater revealed that the WHTW was dominated by the genera Thermoanaerobacterium and Paenibacillus while in the biofilm developed in the anode the main genera were Hydrogenophilus and Anaerobaculum. It has been shown for the first time that highly polluted wood industry wastewater may be effectively treated in MFC systems and the use of appropriate bacterial consortium may result in enhancing power generation accompanying wastewater treatment.
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Affiliation(s)
| | - Karolina Szymona
- Warsaw University of Life Sciences, Faculty of Wood Technology, 159 Nowoursynowska St, Warsaw, Poland
| | - Monika Kloch
- Warsaw University of Life Sciences, Faculty of Wood Technology, 159 Nowoursynowska St, Warsaw, Poland
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