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Yu M, Guo W, Liang Y, Xiang H, Xia Y, Feng H. Towards rapid formation of electroactive biofilm: insights from thermodynamics and electric field manipulation. WATER RESEARCH 2024; 261:121992. [PMID: 38971076 DOI: 10.1016/j.watres.2024.121992] [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: 04/03/2024] [Revised: 06/19/2024] [Accepted: 06/21/2024] [Indexed: 07/08/2024]
Abstract
Electroactive biofilm (EAB) has garnered significant attention due to its effectiveness in pollutant remediation, electricity generation, and chemical synthesis. However, achieving precise control over the rapid formation of EAB presents challenges for the practical implementation of bioelectrochemical technology. In this study, we investigated the regulation of EAB formation by manipulating applied electric potential. We developed a modified XDLVO model for the applied electric field and quantitatively assessed the feasibility of existing rapid formation strategies for EAB. Our results revealed that electrostatic (EL) force significantly influenced EAB formation in the presence of the applied electric field, with the potential difference between the electrode and the microbial solution being the primary determinant of EL force. Compared to -0.2 V and 0 V vs.Ag/AgCl, EAB exhibited the highest electrochemical performance at 0.2 V vs.Ag/AgCl, with a maximum current density of 6.044 ± 0.10 A/m2, surpassing that at -0.2 V vs.Ag/AgCl and 0 V vs.Ag/AgCl by 1.73 times and 1.31 times, respectively. Furthermore, EAB demonstrated the highest biomass accumulation, measuring a thickness of 25 ± 2 μm at 0.2 V vs. Ag/AgCl, representing increases of 1.67 and 1.25 times compared to -0.2 V vs.Ag/AgCl and 0 V vs.Ag/AgCl, respectively. The strong electrostatic attraction under the anodic potential promoted the formation of a monolayer of biofilm. Additionally, the hydrophilicity and hydrophobicity of the biofilm were altered following inversion culture. The Lewis acid-base (AB) attraction offset the electrostatic repulsion caused by negative charges, it is beneficial for the formation of biofilms. This study, for the first time, elucidated the difference in the formation of cathode and anode biofilm from a thermodynamic perspective in the context of electric field introduction, laying the theoretical foundation for the directional regulation of the rapid formation of typical electroactive biofilms.
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Affiliation(s)
- Mengfan Yu
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, Zhejiang, China
| | - Wei Guo
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, Zhejiang, China
| | - Yuxiang Liang
- College of Environment and Resources, College of Carbon Neutral, Zhejiang A&F University, Hangzhou 311300, Zhejiang, China; Sino-Spain Joint Laboratory for Agricultural Environment Emerging Contaminants of Zhejiang Province, Zhejiang A&F University, Hangzhou 311300, Zhejiang, China
| | - Hai Xiang
- College of Environment and Resources, College of Carbon Neutral, Zhejiang A&F University, Hangzhou 311300, Zhejiang, China; Sino-Spain Joint Laboratory for Agricultural Environment Emerging Contaminants of Zhejiang Province, Zhejiang A&F University, Hangzhou 311300, Zhejiang, China
| | - Yijing Xia
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, Zhejiang, China
| | - Huajun Feng
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, Zhejiang, China; College of Environment and Resources, College of Carbon Neutral, Zhejiang A&F University, Hangzhou 311300, Zhejiang, China; Sino-Spain Joint Laboratory for Agricultural Environment Emerging Contaminants of Zhejiang Province, Zhejiang A&F University, Hangzhou 311300, Zhejiang, China.
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Veerubhotla R, Marzocchi U. Examining the resistance and resilience of anode-respiring Shewanella oneidensis biohybrid using microsensors. CHEMOSPHERE 2024; 350:141109. [PMID: 38176592 DOI: 10.1016/j.chemosphere.2024.141109] [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: 08/09/2023] [Revised: 12/09/2023] [Accepted: 01/01/2024] [Indexed: 01/06/2024]
Abstract
Immobilizing electro-active microbes within polymer matrices (thereby forming biohybrids) is a promising approach to accelerate microbial attachment to electrodes and increase the biofilm robustness. However, little is known on the fine scale chemical environment that develops within the electro-active biohybrids. Herein, we develop a biohybrid by immobilizing a culture of Shewanella oneidensis MR1 in agar matrix on the surface of a graphite electrode poised at +0.25 V. The resulting bioanode (3-6 mm thick) was grown under anoxic conditions and produced a steady current of 40 μA. Oxygen and pH distribution within the biohybrid were characterized in-situ using microsensors. As Shewanella is a facultative aerobe, it will halt the current production in the presence of oxygen. Thus, in addition, we investigated the alteration of the microenvironment during and after aeration of the medium to evaluate the oxygen tolerance of the system. During aeration, oxygen was effectively consumed in the top layers of the biofilm, leaving a 400-900 μm thick anoxic zone on the anode surface, that sustained >60% of the initial current. Current production recovered to pre-oxic condition within 5 h after the aeration was stopped, showing that immobilization can promote both high resistance and resilience of the system. Despite the absence of strong buffering conditions, pH profiles indicated a maximum drop of 0.2 units across the biohybrid. Characterizing the chemical microenvironment helps to elucidate the mechanistic functioning of artificial biofilms and hold a great potential for the designing of future, more effective biohybrid electrodes.
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Affiliation(s)
- Ramya Veerubhotla
- Aarhus University Center for Water Technology WATEC, Department of Biology, Aarhus University, Denmark.
| | - Ugo Marzocchi
- Aarhus University Center for Water Technology WATEC, Department of Biology, Aarhus University, Denmark; Center for Electromicrobiology CEM, Department of Biology, Aarhus University, Denmark
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3
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Ye Y, Zhang L, Hong X, Chen M, Liu X, Zhou S. Interspecies ecological competition rejuvenates decayed Geobacter electroactive biofilm. THE ISME JOURNAL 2024; 18:wrae118. [PMID: 38916438 PMCID: PMC11227281 DOI: 10.1093/ismejo/wrae118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 06/05/2024] [Accepted: 06/23/2024] [Indexed: 06/26/2024]
Abstract
Bioelectrochemical systems (BESs) exploit electroactive biofilms (EABs) for promising applications in biosensing, wastewater treatment, energy production, and chemical biosynthesis. However, during the operation of BESs, EABs inevitably decay. Seeking approaches to rejuvenate decayed EABs is critical for the sustainability and practical application of BESs. Prophage induction has been recognized as the primary reason for EAB decay. Herein, we report that introducing a competitive species of Geobacter uraniireducens suspended prophage induction in Geobacter sulfurreducens and thereby rejuvenated the decayed G. sulfurreducens EAB. The transcriptomic profile of G. sulfurreducens demonstrated that the addition of G. uraniireducens significantly affected the expression of metabolism- and stress response system-related genes and in particular suppressed the induction of phage-related genes. Mechanistic analyses revealed that interspecies ecological competition exerted by G. uraniireducens suppressed prophage induction. Our findings not only reveal a novel strategy to rejuvenate decayed EABs, which is significant for the sustainability of BESs, but also provide new knowledge for understanding phage-host interactions from an ecological perspective, with implications for developing therapies to defend against phage attack.
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Affiliation(s)
- Yin Ye
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Lu Zhang
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xiaohui Hong
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Man Chen
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xing Liu
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Shungui Zhou
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
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Shi H, Jiang X, Wen X, Hou C, Chen D, Mu Y, Shen J. Enhanced azo dye reduction at semiconductor-microbe interface: The key role of semiconductor band structure. WATER RESEARCH 2024; 248:120846. [PMID: 37952328 DOI: 10.1016/j.watres.2023.120846] [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: 03/26/2023] [Revised: 11/02/2023] [Accepted: 11/07/2023] [Indexed: 11/14/2023]
Abstract
Low-energy environmental remediation could be achieved by biocatalysis with assistance of light-excited semiconductor, in which the energy band structure of semiconductor has a significant influence on the metabolic process and electron transfer of microbes. In this study, direct Z-scheme and type II heterojunction semiconductor with different energy band structure were successfully synthesized for constructing semiconductor-microbe interface with Shewanella oneidensis MR-1 to achieve acid orange7 (AO7) biodegradation. UV-vis diffuse reflection spectroscopy, photoluminescence spectra and photoelectrochemical analysis revealed that the direct Z-scheme heterojunction semiconductor had stronger reduction power and faster separation of photoelectron-hole, which was beneficial for the AO7 biodegradation at semiconductor-microbe interface. Riboflavin was also involved in electron transfer between the semiconductor and microbes during AO7 reduction. Transcriptome results illustrated that functional gene expression of Shewanella oneidensis MR-1 was upregulated significantly with photo-stimulation of direct Z-scheme semiconductor, and Mtr pathway and conductive pili played the important roles in the photoelectron utilization by Shewanella oneidensis MR-1. This work is expected to provide alternative ideas for designing semiconductor-microbial interface with efficient electron transfer and broadening their applications in bioremediation.
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Affiliation(s)
- Hefei Shi
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China; School of Resources and Environmental Engineering, Jiangsu University of Technology, Changzhou 213001, China
| | - Xinbai Jiang
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
| | - Xiaojiao Wen
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Cheng Hou
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Dan Chen
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Yang Mu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science & Technology of China, Hefei 230026, China
| | - Jinyou Shen
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
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Mukherjee S, Bhattacharjee S, Paul S, Nath S, Paul S. Biofilm-a Syntrophic Consortia of Microbial Cells: Boon or Bane? Appl Biochem Biotechnol 2023; 195:5583-5604. [PMID: 35829902 DOI: 10.1007/s12010-022-04075-4] [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: 03/21/2022] [Accepted: 07/05/2022] [Indexed: 11/30/2022]
Abstract
Biofilm is the conglomeration of microbial cells which is associated with a surface. In the recent times, the study of biofilm has gained popularity and vivid research is being done to know about the effects of biofilm and that it consists of many organisms which are symbiotic in nature, some of which are human pathogens. Here, in this study, we have discussed about biofilms, its formation, relevance of its presence in the biosphere, and the possible remediations to cope up with its negative effects. Since removal of biofilm is difficult, emphasis has been made to suggest ways to prevent biofilm formation and also to devise ways to utilize biofilm in an economically and environment-friendly method.
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Affiliation(s)
- Susmita Mukherjee
- Department of Biotechnology, University of Engineering and Management, University Area, Plot No. III - B/5, New Town, Action Area - III, Kolkata, West Bengal, 700160, India
| | - Shreya Bhattacharjee
- Department of Biotechnology, University of Engineering and Management, University Area, Plot No. III - B/5, New Town, Action Area - III, Kolkata, West Bengal, 700160, India
| | - Sharanya Paul
- Department of Biotechnology, University of Engineering and Management, University Area, Plot No. III - B/5, New Town, Action Area - III, Kolkata, West Bengal, 700160, India
| | - Somava Nath
- Department of Biotechnology, University of Engineering and Management, University Area, Plot No. III - B/5, New Town, Action Area - III, Kolkata, West Bengal, 700160, India
| | - Sonali Paul
- Department of Biotechnology, University of Engineering and Management, University Area, Plot No. III - B/5, New Town, Action Area - III, Kolkata, West Bengal, 700160, India.
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6
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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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Zhao Q, Liu Y, Liao C, Yan X, Tian L, Li T, Li N, Wang X. Reduction of S 0 deposited on electroactive biofilm under an oxidative potential. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 882:163698. [PMID: 37094684 DOI: 10.1016/j.scitotenv.2023.163698] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/13/2023] [Accepted: 04/19/2023] [Indexed: 05/03/2023]
Abstract
The inevitable deposition of S0 on the electroactive biofilm (EAB) via anodic sulfide oxidation affects the stability of bioelectrochemical systems (BESs) when an accidental discharge of sulfide occurred, leading to the inhibition of electroacitivity, because the potential of anode (e.g., 0 V versus Ag/AgCl) is ~500 mV more positive than the redox potential of S2-/S0. Here we found that S0 deposited on the EAB can be spontaneously reduced under this oxidative potential independent of microbial community variation, leading to a self-recovery of electroactivity (> 100 % in current density) with biofilm thickening (~210 μm). Transcriptomics of pure culture indicated that Geobacter highly expressed genes involving in S0 metabolism, which had an additional benefit to improve the viability (25 % - 36 %) of bacterial cells in biofilm distant from the anode and the cellular metabolic activity via electron shuttle pair of S0/S2-(Sx2-). Our findings highlighted the importance of spatially heterogeneous metabolism to its stability when EABs encountered with the problem of S0 deposition, and that in turn improved the electroactivity of EABs.
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Affiliation(s)
- Qian Zhao
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, No. 38 Tongyan Road, Jinnan District, Tianjin 300350, China
| | - Ying Liu
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, No. 38 Tongyan Road, Jinnan District, Tianjin 300350, China
| | - Chengmei Liao
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, No. 38 Tongyan Road, Jinnan District, Tianjin 300350, China
| | - Xuejun Yan
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, No. 38 Tongyan Road, Jinnan District, Tianjin 300350, China
| | - Lili Tian
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, No. 38 Tongyan Road, Jinnan District, Tianjin 300350, China
| | - Tian Li
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, No. 38 Tongyan Road, Jinnan District, Tianjin 300350, China
| | - Nan Li
- School of Environmental Science and Engineering, Tianjin University, No. 135 Yaguan Road, Jinnan District, Tianjin 300350, China
| | - Xin Wang
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, No. 38 Tongyan Road, Jinnan District, Tianjin 300350, China.
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Liu X, Ye Y, Zhang Z, Rensing C, Zhou S, Nealson KH. Prophage Induction Causes Geobacter Electroactive Biofilm Decay. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:6196-6204. [PMID: 36997849 DOI: 10.1021/acs.est.2c08443] [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: 06/19/2023]
Abstract
Sustaining a metabolically active electroactive biofilm (EAB) is essential for the high efficiency and durable operation of microbial fuel cells (MFCs). However, EABs usually decay during long-term operation, and, until now, the causes remain unknown. Here, we report that lysogenic phages can cause EAB decay in Geobacter sulfurreducens fuel cells. A cross-streak agar assay and bioinformatic analysis revealed the presence of prophages on the G. sulfurreducens genome, and a mitomycin C induction assay revealed the lysogenic to lytic transition of those prophages, resulting in a progressive decay in both current generation and the EAB. Furthermore, the addition of phages purified from decayed EAB resulted in accelerated decay of the EAB, thereafter contributing to a faster decline in current generation; otherwise, deleting prophage-related genes rescued the decay process. Our study provides the first evidence of an interaction between phages and electroactive bacteria and suggests that attack by phages is a primary cause of EAB decay, having significant implications in bioelectrochemical systems.
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Affiliation(s)
- Xing Liu
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yin Ye
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Zhishuai Zhang
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Christopher Rensing
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Shungui Zhou
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Kenneth H Nealson
- Department of Earth Science, University of Southern California, Los Angeles, California 90089, United States
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Budak M, Günal E, Kılıç M, Çelik İ, Sırrı M, Acir N. Improvement of spatial estimation for soil organic carbon stocks in Yuksekova plain using Sentinel 2 imagery and gradient descent-boosted regression tree. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:53253-53274. [PMID: 36853536 DOI: 10.1007/s11356-023-26064-8] [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: 11/03/2022] [Accepted: 02/17/2023] [Indexed: 06/18/2023]
Abstract
Carbon sequestration in earth surface is higher than the atmosphere, and the amount of carbon stored in wetlands is much greater than all other land surfaces. The purpose of this study was to estimate soil organic carbon stocks (SOCS) and investigate spatial distribution pattern of Yuksekova wetlands and surrounding lands in Hakkari province of Turkey using machine learning and remote sensing data. Disturbed and undisturbed soil samples were collected from 10-cm depth in 50 locations differed with land use and land cover. Vegetation, soil, and moisture indices were calculated using Sentinel 2 Multispectral Sensor Instrument (MSI) data. Significant correlations (p≤0.01) were obtained between the indices and SOCS; thus, the remote sensing indices (ARVI 0.43, BI -0.43, GSI -0.39, GNDI 0.44, NDVI 0.44, NDWI 0.38, and SRCI 0.51) were used as covariates in multi-layer perceptron neural network (MLP) and gradient descent-boosted regression tree (GBDT) machine learning models. Mean absolute error, root mean square error, and mean absolute percentage error were 3.94 (Mg C ha -1), 6.64 (Mg C ha-1), and 9.97%, respectively. The simple ratio clay index (SRCI), which represents the soil texture, was the most important factor in the SOCS estimation variance. In addition, the relationship between SRCI and Topsoil Grain Size Index revealed that topsoil clay content is a highly important parameter in spatial variation of SOCS. The spatial SOCS values obtained using the GBDT model and the mean SOCS values of the CORINE land cover classes were significantly different. The land cover has a significant effect on SOC in Yuksekova plain. The mean SOCS for continuously ponded fields was 45.58 Mg C ha-1, which was significantly different from the mean SOCS of arable lands. The mean SOCS in arable lands, with significant areas of natural vegetation, was 50.22 Mg C ha-1 and this amount was significantly higher from the SOCS of other land covers (p<0.01). The wetlands had the highest SOCS (61.46 Mg C ha-1), followed by the lands principally occupied by natural vegetation and used as rangelands around the wetland (50.22 Mg C ha-1). Environmental conditions had significant effect on SOCS in the study area. The use of remote sensing indices instead of using single bands as estimators in the GBDT algorithm minimized radiometric errors, and reliable spatial SOCS information was obtained by using the estimators. Therefore, the spatial estimation of SOCS can be successfully determined with up-to-date machine learning algorithms only using remote sensing predictor variables. Reliable estimation of SOCS in wetlands and surrounding lands can help understand policy and decision makers the importance of wetlands in mitigating the negative impacts of global warming.
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Affiliation(s)
- Mesut Budak
- Department of Soil Science and Plant Nutrition, Faculty of Agriculture, Siirt University, Siirt, Turkey
| | | | - Miraç Kılıç
- Department of Plant and Animal Production, Vocational School of Kahta, Adiyaman University, Adiyaman, Turkey.
| | - İsmail Çelik
- Department of Soil Science and Plant Nutrition, Faculty of Agriculture, Cukurova University, Adana, Turkey
| | - Mesut Sırrı
- Department of Plant and Animal Production, Vocational School of Kurtalan, Siirt University, Siirt, Turkey
| | - Nurullah Acir
- Department of Soil Science and Plant Nutrition, Faculty of Agriculture, Kirsehir Ahi Evran University, Kirsehir, Turkey
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Martinez Ostormujof L, Teychené S, Achouak W, Fochesato S, Bakarat M, Rodriguez‐Ruiz I, Bergel A, Erable B. Systemic Analysis of the Spatiotemporal Changes in Multi‐Species Electroactive Biofilms to Clarify the Gradual Decline of Current Generation in Microbial Anodes. ChemElectroChem 2023. [DOI: 10.1002/celc.202201135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
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11
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Wang T, Kuang B, Ni Z, Guo B, Li Y, Zhu G. Stimulating Anaerobic Degradation of Butyrate via Syntrophomonas wolfei and Geobacter sulfurreducens: Characteristics and Mechanism. MICROBIAL ECOLOGY 2023; 85:535-543. [PMID: 35254501 DOI: 10.1007/s00248-022-01981-2] [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: 01/09/2022] [Accepted: 02/14/2022] [Indexed: 06/14/2023]
Abstract
Anaerobic digestion (AD) has been widely applied for the degradation of organic wastewater due to its advantages of high-load operation and energy recovery. However, some challenges, such as low treatment capacity and instability caused by the accumulation of volatile fatty acids, limit its further application. Here, S. wolfei and G. sulfurreducens were initially co-cultured in the anaerobic anode of bio-electrochemical system for degrading butyric acid. Butyrate degradation characteristics in different conditions were quantitatively described. Moreover, G. sulfurreducens simultaneously strengthened the consumption of H2 and acetic acid via direct interspecies electron transfer, thereby strengthening the degradation of butyric acid via a co-metabolic process. During butyrate degradation, the co-culture of S. wolfei and G. sulfurreducens showed more advantages than that of S. wolfei and methanogens. This present study provides a new perspective of butyrate metabolism, which was independent of methanogens in an AD process.
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Affiliation(s)
- Tao Wang
- School of Environment and Nature Resources, Renmin University of China, Beijing, 100872, People's Republic of China
- School of Biotechnology and Health Sciences, Wuyi University, Jiangmen, 529020, People's Republic of China
| | - Bin Kuang
- School of Economics and Management, Jiangmen Polytechnic, Jiangmen, 529020, People's Republic of China
| | - Zhili Ni
- School of Biotechnology and Health Sciences, Wuyi University, Jiangmen, 529020, People's Republic of China
| | - Bing Guo
- Department of Civil and Environmental Engineering, University of Surrey, Surrey, GU2 7XH, UK
| | - Yuying Li
- School of Biotechnology and Health Sciences, Wuyi University, Jiangmen, 529020, People's Republic of China
| | - Gefu Zhu
- School of Environment and Nature Resources, Renmin University of China, Beijing, 100872, People's Republic of China.
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12
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de Smit S, Langedijk JJH, van Haalen LCA, Lin SH, Bitter JH, Strik DPBTB. Methodology for In Situ Microsensor Profiling of Hydrogen, pH, Oxidation-Reduction Potential, and Electric Potential throughout Three-Dimensional Porous Cathodes of (Bio)Electrochemical Systems. Anal Chem 2023; 95:2680-2689. [PMID: 36715453 PMCID: PMC9909735 DOI: 10.1021/acs.analchem.2c03121] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We developed a technique based on the use of microsensors to measure pH and H2 gradients during microbial electrosynthesis. The use of 3D electrodes in (bio)electrochemical systems likely results in the occurrence of gradients from the bulk conditions into the electrode. Since these gradients, e.g., with respect to pH and reactant/product concentrations determine the performance of the electrode, it is essential to be able to accurately measure them. Apart from these parameters, also local oxidation-reduction potential and electric field potential were determined in the electrolyte and throughout the 3D porous electrodes. Key was the realization that the presence of an electric field disturbed the measurements obtained by the potentiometric type of microsensor. To overcome the interference on the pH measure, a method was validated where the signal was corrected for the local electric field measured with the electric potential microsensor. The developed method provides a useful tool for studies about electrode design, reactor engineering, measuring gradients in electroactive biofilms, and flow dynamics in and around 3D porous electrodes of (bio)electrochemical systems.
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Affiliation(s)
- Sanne
M. de Smit
- Environmental
Technology, Wageningen University and Research, Wageningen 6708WG, The Netherlands,Biobased
Chemistry and Technology, Wageningen University
and Research, Wageningen 6708WG, The Netherlands
| | - Jelle J. H. Langedijk
- Environmental
Technology, Wageningen University and Research, Wageningen 6708WG, The Netherlands
| | - Lennert C. A. van Haalen
- Environmental
Technology, Wageningen University and Research, Wageningen 6708WG, The Netherlands
| | - Shih Hsuan Lin
- Environmental
Technology, Wageningen University and Research, Wageningen 6708WG, The Netherlands
| | - Johannes H. Bitter
- Biobased
Chemistry and Technology, Wageningen University
and Research, Wageningen 6708WG, The Netherlands,
| | - David P. B. T. B. Strik
- Environmental
Technology, Wageningen University and Research, Wageningen 6708WG, The Netherlands,
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13
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Kong G, Yang Y, Luo Y, Liu F, Song D, Sun G, Li D, Guo J, Dong M, Xu M. Cysteine-Mediated Extracellular Electron Transfer of Lysinibacillus varians GY32. Microbiol Spectr 2022; 10:e0279822. [PMID: 36318024 PMCID: PMC9769522 DOI: 10.1128/spectrum.02798-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 10/04/2022] [Indexed: 11/06/2022] Open
Abstract
Microbial extracellular electron transfer (EET) is essential in many natural and engineering processes. Compared with the versatile EET pathways of Gram-negative bacteria, the EET of Gram-positive bacteria has been studied much less and is mainly limited to the flavin-mediated pathway. Here, we investigate the EET pathway of a Gram-positive filamentous bacterium Lysinibacillus varians GY32. Strain GY32 has a wide electron donor spectrum (including lactate, acetate, formate, and some amino acids) in electrode respiration. Transcriptomic, proteomic, and electrochemical analyses show that the electrode respiration of GY32 mainly depends on electron mediators, and c-type cytochromes may be involved in its respiration. Fluorescent sensor and electrochemical analyses demonstrate that strain GY32 can secrete cysteine and flavins. Cysteine added shortly after inoculation into microbial fuel cells accelerated EET, showing cysteine is a new endogenous electron mediator of Gram-positive bacteria, which provides novel information to understand the EET networks in natural environments. IMPORTANCE Extracellular electron transport (EET) is a key driving force in biogeochemical element cycles and microbial chemical-electrical-optical energy conversion on the Earth. Gram-positive bacteria are ubiquitous and even dominant in EET-enriched environments. However, attention and knowledge of their EET pathways are largely lacking. Gram-positive bacterium Lysinibacillus varians GY32 has extremely long cells (>1 mm) and conductive nanowires, promising a unique and enormous role in the microenvironments where it lives. Its capability to secrete cysteine renders it not only an EET pathway to respire and survive, but also an electrochemical strategy to connect and shape the ambient microbial community at a millimeter scale. Moreover, its incapability of using flavins as an electron mediator suggests that the common electron mediator is species-dependent. Therefore, our results are important to understanding the EET networks in natural and engineering processes.
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Affiliation(s)
- Guannan Kong
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Yonggang Yang
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Yeshen Luo
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Fei Liu
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Da Song
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Guoping Sun
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Daobo Li
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Jun Guo
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Meijun Dong
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Meiying Xu
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
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14
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Ingino P, Tiew KH, Obst M. Suitability of lectin binding studies for the characterization of redox-active microbial environmental biofilms. AMB Express 2022; 12:140. [DOI: 10.1186/s13568-022-01479-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 10/23/2022] [Indexed: 11/08/2022] Open
Abstract
AbstractAquatic environmental microbial biofilms grow in a broad range of redox environments from oxic to methanogenic, and they often also establish internal redox gradients. In technical applications, biofilms are also subjected to controlled redox conditions. Studies on biofilms often make use of fluorescence microscopic imaging techniques together with lectin binding analysis to gain insights into structure, composition, and functions of the biofilms. Here we studied the direct influence of redox potentials on fluorescence lectin binding analyses (FLBA) for two commonly used lectin-fluorophore conjugates. An effect of the electrical potential on signal intensity was observed and found to be statistically significant. The signal intensity changes however, remained within the range of a few percent total. A significant drop in intensity was only observed for extremely oxidizing potentials, typically not found under environmental conditions. Our results showed that the fluorophore itself and not the lectin binding to the respective glycoconjugate causes fluorescence changes. The two tested lectin-fluorophores are shown to be suitable for studying the distribution and composition of EPS in environmental biofilms or technical applications and under varying redox conditions.
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15
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A new angle to control concentration profiles at electroactive biofilm interfaces: investigating a microfluidic perpendicular flow approach. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2022.141071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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16
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Development of a Versatile, Low-Cost Electrochemical System to Study Biofilm Redox Activity at the Micron Scale. Appl Environ Microbiol 2022; 88:e0043422. [PMID: 35758758 PMCID: PMC9328185 DOI: 10.1128/aem.00434-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Spatially resolving chemical landscapes surrounding microbial communities can provide insight into chemical interactions that dictate cellular physiology. Electrochemical techniques provide an attractive option for studying these interactions due to their robustness and high sensitivity. Unfortunately, commercial electrochemical platforms that are capable of measuring chemical activity on the micron scale are often expensive and do not easily perform multiple scanning techniques. Here, we report development of an inexpensive electrochemical system that features a combined micromanipulator and potentiostat component capable of scanning surfaces while measuring molecular concentrations or redox profiles. We validate this experimental platform for biological use with a two-species biofilm model composed of the oral bacterial pathogen Aggregatibacter actinomycetemcomitans and the oral commensal Streptococcus gordonii. We measure consumption of H2O2 by A. actinomycetemcomitans biofilms temporally and spatially, providing new insights into how A. actinomycetemcomitans responds to this S. gordonii-produced metabolite. We advance our platform to spatially measure redox activity above biofilms. Our analysis supports that redox activity surrounding biofilms is species specific, and the region immediately above an S. gordonii biofilm is highly oxidized compared to that above an A. actinomycetemcomitans biofilm. This work provides description and validation of a versatile, quantitative framework for studying bacterial redox-mediated physiology in an integrated and easily adaptable experimental platform. IMPORTANCE Scanning electrochemical probe microscopy methods can provide information of the chemical environment along a spatial surface with micron-scale resolution. These methods often require expensive instruments that perform optimized and highly sensitive niche techniques. Here, we describe a novel system that combines a micromanipulator that scans micron-sized electrodes across the surface of bacterial biofilms and a potentiostat, which performs various electrochemical techniques. This platform allows for spatial measurement of chemical gradients above live bacteria in real time, and as proof of concept, we utilize this setup to map H2O2 detoxification above an oral pathogen biofilm. We increased the versatility of this platform further by mapping redox potentials of biofilms in real time on the micron scale. Together, this system provides a technical framework for studying chemical interactions among microbes.
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17
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Häuser L, Erben J, Pillot G, Kerzenmacher S, Dreher W, Küstermann E. In vivo characterization of electroactive biofilms inside porous electrodes with MR Imaging. RSC Adv 2022; 12:17784-17793. [PMID: 35765339 PMCID: PMC9199086 DOI: 10.1039/d2ra01162j] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 05/30/2022] [Indexed: 12/03/2022] Open
Abstract
Identifying the limiting processes of electroactive biofilms is key to improve the performance of bioelectrochemical systems (BES). For modelling and developing BES, spatial information of transport phenomena and biofilm distribution are required and can be determined by Magnetic Resonance Imaging (MRI) in vivo, in situ and in operando even inside opaque porous electrodes. A custom bioelectrochemical cell was designed that allows MRI measurements with a spatial resolution of 50 μm inside a 500 μm thick porous carbon electrode. The MRI data showed that only a fraction of the electrode pore space is colonized by the Shewanella oneidensis MR-1 biofilm. The maximum biofilm density was observed inside the porous electrode close to the electrode-medium interface. Inside the biofilm, mass transport by diffusion is lowered down to 45% compared to the bulk growth medium. The presented data and the methods can be used for detailed models of bioelectrochemical systems and for the design of improved electrode structures. The use of magnetic resonance imaging can contribute to a better understanding of limiting processes occurring in electroactive biofilms especially inside opaque porous electrodes.![]()
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Affiliation(s)
- Luca Häuser
- Center for Environmental Research and Sustainable Technology (UFT), University of Bremen 28359 Bremen Germany
| | | | - Guillaume Pillot
- Center for Environmental Research and Sustainable Technology (UFT), University of Bremen 28359 Bremen Germany
| | - Sven Kerzenmacher
- Center for Environmental Research and Sustainable Technology (UFT), University of Bremen 28359 Bremen Germany
| | - Wolfgang Dreher
- In-vivo-MR Group, Faculty 02 (Biology/Chemistry), University of Bremen 28359 Bremen Germany
| | - Ekkehard Küstermann
- In-vivo-MR Group, Faculty 02 (Biology/Chemistry), University of Bremen 28359 Bremen Germany
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18
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Chambonniere P, Bronlund JE, Guieysse B. Study from microcosms and mesocosms reveals Escherichia coli removal in high rate algae ponds during domestic wastewater treatment is primarily caused by dark decay. PLoS One 2022; 17:e0265576. [PMID: 35298558 PMCID: PMC8929646 DOI: 10.1371/journal.pone.0265576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 03/03/2022] [Indexed: 11/24/2022] Open
Abstract
While high rate algal ponds (HRAPs) can provide efficient pathogen removal from wastewater, the mechanisms involved remain unclear. To address this knowledge gap, the mechanisms potentially causing Escherichia coli (E. coli) removal during microalgae-based wastewater treatment were successively assessed using laboratory microcosms designed to isolate known mechanisms, and bench scale assays performed in real HRAP broth. During laboratory assays, E. coli decay was only significantly increased by alkaline pH (above temperature-dependent thresholds) due to pH induced toxicity, and direct sunlight exposure via UV-B damage and/or endogenous photo-oxidation. Bench assays confirmed alkaline pH toxicity caused significant decay but sunlight-mediated decay was not significant, likely due to light attenuation in the HRAP broth. Bench assays also evidenced the existence of uncharacterized ‘dark’ decay mechanism(s) not observed in laboratory microcosms. To numerically evaluate the contribution of each mechanism and the uncertainty associated, E. coli decay was modelled assuming dark decay, alkaline pH induced toxicity, and direct sunlight-mediated decay were independent mechanisms. The simulations confirmed E. coli decay was mainly caused by dark decay during bench assays (48.2–89.5% estimated contribution to overall decay at the 95% confidence level), followed by alkaline-pH induced toxicity (8.3–46.5%), and sunlight-mediated decay (0.0–21.9%).
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Affiliation(s)
- Paul Chambonniere
- Department of Chemical and Bioprocess Engineering, School of Food and Advanced Technology, Massey University, Palmerston North, New Zealand
- * E-mail:
| | - John E. Bronlund
- Department of Chemical and Bioprocess Engineering, School of Food and Advanced Technology, Massey University, Palmerston North, New Zealand
| | - Benoit Guieysse
- Department of Chemical and Bioprocess Engineering, School of Food and Advanced Technology, Massey University, Palmerston North, New Zealand
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19
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Hu Y, Wang Y, Han X, Shan Y, Li F, Shi L. Biofilm Biology and Engineering of Geobacter and Shewanella spp. for Energy Applications. Front Bioeng Biotechnol 2021; 9:786416. [PMID: 34926431 PMCID: PMC8683041 DOI: 10.3389/fbioe.2021.786416] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/18/2021] [Indexed: 01/04/2023] Open
Abstract
Geobacter and Shewanella spp. were discovered in late 1980s as dissimilatory metal-reducing microorganisms that can transfer electrons from cytoplasmic respiratory oxidation reactions to external metal-containing minerals. In addition to mineral-based electron acceptors, Geobacter and Shewanella spp. also can transfer electrons to electrodes. The microorganisms that have abilities to transfer electrons to electrodes are known as exoelectrogens. Because of their remarkable abilities of electron transfer, Geobacter and Shewanella spp. have been the two most well studied groups of exoelectrogens. They are widely used in bioelectrochemical systems (BESs) for various biotechnological applications, such as bioelectricity generation via microbial fuel cells. These applications mostly associate with Geobacter and Shewanella biofilms grown on the surfaces of electrodes. Geobacter and Shewanella biofilms are electrically conductive, which is conferred by matrix-associated electroactive components such as c-type cytochromes and electrically conductive nanowires. The thickness and electroactivity of Geobacter and Shewanella biofilms have a significant impact on electron transfer efficiency in BESs. In this review, we first briefly discuss the roles of planktonic and biofilm-forming Geobacter and Shewanella cells in BESs, and then review biofilm biology with the focus on biofilm development, biofilm matrix, heterogeneity in biofilm and signaling regulatory systems mediating formation of Geobacter and Shewanella biofilms. Finally, we discuss strategies of Geobacter and Shewanella biofilm engineering for improving electron transfer efficiency to obtain enhanced BES performance.
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Affiliation(s)
- Yidan Hu
- Department of Biological Sciences and Technology, School of Environmental Studies, China University of Geosciences, Wuhan, China
| | - Yinghui Wang
- Department of Biological Sciences and Technology, School of Environmental Studies, China University of Geosciences, Wuhan, China
| | - Xi Han
- Department of Biological Sciences and Technology, School of Environmental Studies, China University of Geosciences, Wuhan, China
| | - Yawei Shan
- Department of Biological Sciences and Technology, School of Environmental Studies, China University of Geosciences, Wuhan, China
| | - Feng Li
- Key Laboratory of Systems Bioengineering (Ministry of Education), SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Liang Shi
- Department of Biological Sciences and Technology, School of Environmental Studies, China University of Geosciences, Wuhan, China.,State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China.,Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, China University of Geosciences, Wuhan, China.,State Environmental Protection Key Laboratory of Source Apportionment and Control of Aquatic Pollution, Ministry of Ecology and Environment, Wuhan, China
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20
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Electrografted anthraquinone to monitor pH at the biofilm-anode interface in a wastewater microbial fuel cell. Colloids Surf B Biointerfaces 2021; 210:112274. [PMID: 34894599 DOI: 10.1016/j.colsurfb.2021.112274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 11/27/2021] [Accepted: 12/03/2021] [Indexed: 11/20/2022]
Abstract
Electrografted anthraquinone on graphite was used as a probe to monitor the pH change at the biofilm-electrode interface at the anode of a microbial fuel cell inoculated with wastewater. The grafting procedure was optimized so that the pH-dependent electrochemical response of the grafted quinone did not overlay with that of the electroactive biofilm. The variation of the formal potential of the grafted quinone as a function of pH was linear over the pH range 1-10 with a slope of - 64 mV. This allowed to monitor the interfacial pH change over three weeks of biofilm colonization of the electrode. During that time the interfacial pH decreased from neutrality to 5.3 while the anolyte only acidified down to pH 6.2. This finding is relevant as local pH change usually leads to alterations of the bioenergetics process of microbial communities and hence on the performance of bioelectrochemical devices.
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21
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Wang T, Zhu G, Kuang B, Jia J, Liu C, Cai G, Li C. Novel insights into the anaerobic digestion of propionate via Syntrophobacter fumaroxidans and Geobacter sulfurreducens: Process and mechanism. WATER RESEARCH 2021; 200:117270. [PMID: 34077836 DOI: 10.1016/j.watres.2021.117270] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 04/21/2021] [Accepted: 05/14/2021] [Indexed: 06/12/2023]
Abstract
The accumulation of volatile fatty acids, particularly propionic acid, significantly inhibits the efficiency of the anaerobic digestion system. In propionate degradation metabolism, the unfavorable thermodynamics of syntrophic reactions, strict ecological niche of syntrophic priopionate oxidizing bacteria, and slow metabolic rate of methanogens are regarded as major limitations. In this study, Geobacter sulfurreducens was co-cultured with Syntrophobacter fumaroxidans in bioelelectrochemical cells to analyze the propionate degradation process, impact factor, mechanism metabolic pathways, and electron transfer comprehensively. The results revealed that the syntroph S. fumaroxidans and syntrophic partner G. sulfurreducens achieved more efficient propionate degradation than the control group, comprising S. fumaroxidans and methanogens. Moreover, the carbon resource concentration and pH were both significantly correlated with propionate degradation (P < 0.01). The results further confirmed that G. sulfurreducen strengthened the consumption of H2 and acetate via direct interspecific electron transfer in propionate degradation. These findings indicate that G. sulfurreducens plays an unidentified functional role in propionate degradation.
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Affiliation(s)
- Tao Wang
- School of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529020, PR China
| | - Gefu Zhu
- School of Environment and Nature Resources, Renmin University of China, Beijing 100872, PR China
| | - Bin Kuang
- School of Economics and Management, Jiangmen Polytechnic, Jiangmen 529020, PR China
| | - Jianbo Jia
- School of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529020, PR China
| | - Changyu Liu
- School of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529020, PR China
| | - Guanjing Cai
- Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, PR China
| | - Chunxing Li
- Department of Chemical and Biochemical Engineering, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark
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22
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Erben J, Pinder ZA, Lüdtke MS, Kerzenmacher S. Local Acidification Limits the Current Production and Biofilm Formation of Shewanella oneidensis MR-1 With Electrospun Anodes. Front Microbiol 2021; 12:660474. [PMID: 34194407 PMCID: PMC8236948 DOI: 10.3389/fmicb.2021.660474] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 05/03/2021] [Indexed: 11/30/2022] Open
Abstract
The anodic current production of Shewanella oneidensis MR-1 is typically lower compared to other electroactive bacteria. The main reason for the low current densities is the poor biofilm growth on most anode materials. We demonstrate that the high current production of Shewanella oneidensis MR-1 with electrospun anodes exhibits a similar threshold current density as dense Geobacter spp biofilms. The threshold current density is a result of local acidification in the biofilm. Increasing buffer concentration from 10 to 40 mM results in a 1.8-fold increase of the current density [(590 ± 25) μA cm−2] while biofilm growth stimulation by riboflavin has little effect on the current production. The current production of a reference material below the threshold did not respond to the increased buffer concentration but could be enhanced by supplemented riboflavin that stimulated the biofilm growth. Our results suggest that the current production with S. oneidensis is limited (1) by the biofilm growth on the anode that can be enhanced by the choice of the electrode material, and (2) by the proton transport through the biofilm and the associated local acidification.
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Affiliation(s)
- Johannes Erben
- Center for Environmental Research and Sustainable Technology (UFT), University of Bremen, Bremen, Germany
| | | | - Malte S Lüdtke
- Center for Environmental Research and Sustainable Technology (UFT), University of Bremen, Bremen, Germany
| | - Sven Kerzenmacher
- Center for Environmental Research and Sustainable Technology (UFT), University of Bremen, Bremen, Germany
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23
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Functional Interrelationships of Microorganisms in Iron-Based Anaerobic Wastewater Treatment. Microorganisms 2021; 9:microorganisms9051039. [PMID: 34065964 PMCID: PMC8151836 DOI: 10.3390/microorganisms9051039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 05/07/2021] [Accepted: 05/10/2021] [Indexed: 11/16/2022] Open
Abstract
This study explicated the functional activities of microorganisms and their interrelationships under four previously reported iron reducing conditions to identify critical factors that governed the performance of these novel iron-dosed anaerobic biological wastewater treatment processes. Various iron-reducing bacteria (FeRB) and sulfate reducing bacteria (SRB) were identified as the predominant species that concurrently facilitated organics oxidation and the main contributors to removal of organics. The high organic contents of wastewater provided sufficient electron donors for active growth of both FeRB and SRB. In addition to the organic content, Fe (III) and sulfate concentrations (expressed by Fe/S ratio) were found to play a significant role in regulating the microbial abundance and functional activities. Various fermentative bacteria contributed to this FeRB-SRB synergy by fermenting larger organic compounds to smaller compounds, which were subsequently used by FeRB and SRB. Feammox (ferric reduction coupled to ammonium oxidation) bacterium was identified in the bioreactor fed with wastewater containing ammonium. Organic substrate level was a critical factor that regulated the competitive relationship between heterotrophic FeRB and Feammox bacteria. There were evidences that suggested a synergistic relationship between FeRB and nitrogen-fixing bacteria (NFB), where ferric iron and organics concentrations both promoted microbial activities of FeRB and NFB. A concept model was developed to illustrate the identified functional interrelationships and their governing factors for further development of the iron-based wastewater treatment systems.
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24
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He X, Chadwick G, Jiménez Otero F, Orphan V, Meile C. Spatially Resolved Electron Transport through Anode‐Respiring
Geobacter sulfurreducens
Biofilms: Controls and Constraints. ChemElectroChem 2021. [DOI: 10.1002/celc.202100111] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Xiaojia He
- Department of Marine Sciences University of Georgia Athens GA USA
| | - Grayson Chadwick
- Division of Geological and Planetary Sciences California Institute of Technology Pasadena CA USA
| | | | - Victoria Orphan
- Division of Geological and Planetary Sciences California Institute of Technology Pasadena CA USA
| | - Christof Meile
- Department of Marine Sciences University of Georgia Athens GA USA
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25
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Dissecting the Structural and Conductive Functions of Nanowires in Geobacter sulfurreducens Electroactive Biofilms. mBio 2021; 13:e0382221. [PMID: 35164556 PMCID: PMC8844916 DOI: 10.1128/mbio.03822-21] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Conductive nanowires are thought to contribute to long-range electron transfer (LET) in Geobacter sulfurreducens anode biofilms. Three types of nanowires have been identified: pili, OmcS, and OmcZ. Previous studies highlighted their conductive function in anode biofilms, yet a structural function also has to be considered. We present here a comprehensive analysis of the function of nanowires in LET by inhibiting the expression of each nanowire. Meanwhile, flagella with poor conductivity were expressed to recover the structural function but not the conductive function of nanowires in the corresponding nanowire mutant strain. The results demonstrated that pili played a structural but not a conductive function in supporting biofilm formation. In contrast, the OmcS nanowire played a conductive but not a structural function in facilitating electron transfer in the biofilm. The OmcZ nanowire played both a structural and a conductive function to contribute to current generation. Expression of the poorly conductive flagellum was shown to enhance biofilm formation, subsequently increasing current generation. These data support a model in which multiheme cytochromes facilitate long-distance electron transfer in G. sulfurreducens biofilms. Our findings also suggest that the formation of a thicker biofilm, which contributed to a higher current generation by G. sulfurreducens, was confined by the biofilm formation deficiency, and this has applications in microbial electrochemical systems. IMPORTANCE The low power generation of microbial fuel cells limits their utility. Many factors can affect power generation, including inefficient electron transfer in the anode biofilm. Thus, understanding the mechanism(s) of electron transfer provides a pathway for increasing the power density of microbial fuel cells. Geobacter sulfurreducens was shown to form a thick biofilm on the anode. Cells far away from the anode reduce the anode through long-range electron transfer. Based on their conductive properties, three types of nanowires have been hypothesized to directly facilitate long-range electron transfer: pili, OmcS, and OmcZ nanowires. However, their structural contributions to electron transfer in anode biofilm have not been elucidated. Based on studies of mutants lacking one or more of these facilitators, our results support a cytochrome-mediated electron transfer process in Geobacter biofilms and highlight the structural contribution of nanowires in anode biofilm formation, which contributes to biofilm formation and current generation, thereby providing a strategy to increase current generation.
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Guo F, Babauta JT, Beyenal H. The effect of additional salinity on performance of a phosphate buffer saline buffered three-electrode bioelectrochemical system inoculated with wastewater. BIORESOURCE TECHNOLOGY 2021; 320:124291. [PMID: 33157437 DOI: 10.1016/j.biortech.2020.124291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/14/2020] [Accepted: 10/15/2020] [Indexed: 06/11/2023]
Abstract
In bioelectrochemical system (BES), phosphate buffer saline (PBS) is usually used to achieve a suitable pH condition, which also increases electrolyte salinity. A series of factors that change with salinity will affect BES performance. To simplify the scenario, a three-electrode BES is used to investigate how additional salinity affects the performance of a 50 mM PBS-buffered BES. Results demonstrated that current production decreased with increasing salinity and the dominant exoelectrogens were not inhibited with the addition of 200 mM NaCl. The distribution of system resistance was analyzed by electrochemical impedance spectroscopy. Compared to the decreased solution and biofilm resistance, the increased interfacial resistance that accounted for up to 97.8% of total resistance was the dominant reason for the decreased current production with the increasing additional salinity. The effects of additional salinity on acetate degradation and columbic efficiency were also analyzed.
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Affiliation(s)
- Fei Guo
- School of Civil Engineering, Architecture and Environment, Xihua University, Chengdu 610039, China; The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, USA.
| | - Jerome T Babauta
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, USA
| | - Haluk Beyenal
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, USA
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27
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Pinck S, Ostormujof LM, Teychené S, Erable B. Microfluidic Microbial Bioelectrochemical Systems: An Integrated Investigation Platform for a More Fundamental Understanding of Electroactive Bacterial Biofilms. Microorganisms 2020; 8:E1841. [PMID: 33238493 PMCID: PMC7700166 DOI: 10.3390/microorganisms8111841] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 12/31/2022] Open
Abstract
It is the ambition of many researchers to finally be able to close in on the fundamental, coupled phenomena that occur during the formation and expression of electrocatalytic activity in electroactive biofilms. It is because of this desire to understand that bioelectrochemical systems (BESs) have been miniaturized into microBES by taking advantage of the worldwide development of microfluidics. Microfluidics tools applied to bioelectrochemistry permit even more fundamental studies of interactions and coupled phenomena occurring at the microscale, thanks, in particular, to the concomitant combination of electroanalysis, spectroscopic analytical techniques and real-time microscopy that is now possible. The analytical microsystem is therefore much better suited to the monitoring, not only of electroactive biofilm formation but also of the expression and disentangling of extracellular electron transfer (EET) catalytic mechanisms. This article reviews the details of the configurations of microfluidic BESs designed for selected objectives and their microfabrication techniques. Because the aim is to manipulate microvolumes and due to the high modularity of the experimental systems, the interfacial conditions between electrodes and electrolytes are perfectly controlled in terms of physicochemistry (pH, nutrients, chemical effectors, etc.) and hydrodynamics (shear, material transport, etc.). Most of the theoretical advances have been obtained thanks to work carried out using models of electroactive bacteria monocultures, mainly to simplify biological investigation systems. However, a huge virgin field of investigation still remains to be explored by taking advantage of the capacities of microfluidic BESs regarding the complexity and interactions of mixed electroactive biofilms.
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Affiliation(s)
| | | | | | - Benjamin Erable
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INPT, UPS, 31432 Toulouse, France; (S.P.); (L.M.O.); (S.T.)
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Hill A, Tait S, Baillie C, Virdis B, McCabe B. Microbial electrochemical sensors for volatile fatty acid measurement in high strength wastewaters: A review. Biosens Bioelectron 2020; 165:112409. [DOI: 10.1016/j.bios.2020.112409] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 06/17/2020] [Accepted: 06/22/2020] [Indexed: 12/29/2022]
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29
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Roy S, Xie O, Dorval Courchesne N. Challenges in engineering conductive protein fibres: Disentangling the knowledge. CAN J CHEM ENG 2020. [DOI: 10.1002/cjce.23836] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Sophia Roy
- Department of Chemical Engineering McGill University Montréal Québec Canada
| | - Oliver Xie
- Department of Chemical Engineering McGill University Montréal Québec Canada
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30
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Effect of electrode spacing on electron transfer and conductivity of Geobacter sulfurreducens biofilms. Bioelectrochemistry 2020; 131:107395. [DOI: 10.1016/j.bioelechem.2019.107395] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 09/12/2019] [Accepted: 09/13/2019] [Indexed: 12/19/2022]
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31
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Liu X, Zhuo S, Jing X, Yuan Y, Rensing C, Zhou S. Flagella act as Geobacter biofilm scaffolds to stabilize biofilm and facilitate extracellular electron transfer. Biosens Bioelectron 2019; 146:111748. [DOI: 10.1016/j.bios.2019.111748] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 09/22/2019] [Accepted: 09/30/2019] [Indexed: 11/24/2022]
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32
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Abstract
Electricity-producing bacteria are potential power sources, fermentation platforms, and desalination systems, if current densities could be increased. These organisms form conductive biofilms on electrodes, allowing new cell layers to contribute to current production until a limit is reached, but the biological underpinning of this limit is not well-understood. We investigated the limitation behind this phenomenon using stable isotope probing and nanoscale secondary ion mass spectrometry, showing active cells are restricted to layers closest to the electrode. This metabolic observation fundamentally changes our understanding of electron flow and cell growth within current-producing biofilms and provides constraints on the physical structure of natural communities reliant on this process for growth. We predict improvements in biofilm conductivity will yield higher current-producing systems. Metal-reducing bacteria direct electrons to their outer surfaces, where insoluble metal oxides or electrodes act as terminal electron acceptors, generating electrical current from anaerobic respiration. Geobacter sulfurreducens is a commonly enriched electricity-producing organism, forming thick conductive biofilms that magnify total activity by supporting respiration of cells not in direct contact with electrodes. Hypotheses explaining why these biofilms fail to produce higher current densities suggest inhibition by formation of pH, nutrient, or redox potential gradients; but these explanations are often contradictory, and a lack of direct measurements of cellular growth within biofilms prevents discrimination between these models. To address this fundamental question, we measured the anabolic activity of G. sulfurreducens biofilms using stable isotope probing coupled to nanoscale secondary ion mass spectrometry (nanoSIMS). Our results demonstrate that the most active cells are at the anode surface, and that this activity decreases with distance, reaching a minimum 10 µm from the electrode. Cells nearest the electrode continue to grow at their maximum rate in weeks-old biofilms 80-µm-thick, indicating nutrient or buffer diffusion into the biofilm is not rate-limiting. This pattern, where highest activity occurs at the electrode and declines with each cell layer, is present in thin biofilms (<5 µm) and fully grown biofilms (>20 µm), and at different anode redox potentials. These results suggest a growth penalty is associated with respiring insoluble electron acceptors at micron distances, which has important implications for improving microbial electrochemical devices as well as our understanding of syntrophic associations harnessing the phenomenon of microbial conductivity.
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33
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Lebègue E, Costa NL, Fonseca BM, Louro RO, Barrière F. Electrochemical properties of pH-dependent flavocytochrome c3 from Shewanella putrefaciens adsorbed onto unmodified and catechol-modified edge plane pyrolytic graphite electrode. J Electroanal Chem (Lausanne) 2019. [DOI: 10.1016/j.jelechem.2019.113232] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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34
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Reguera G. Microbial nanowires and electroactive biofilms. FEMS Microbiol Ecol 2019; 94:5000162. [PMID: 29931163 DOI: 10.1093/femsec/fiy086] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 05/11/2018] [Indexed: 12/14/2022] Open
Abstract
Geobacter bacteria are the only microorganisms known to produce conductive appendages or pili to electronically connect cells to extracellular electron acceptors such as iron oxide minerals and uranium. The conductive pili also promote cell-cell aggregation and the formation of electroactive biofilms. The hallmark of these electroactive biofilms is electronic heterogeneity, mediated by coordinated interactions between the conductive pili and matrix-associated cytochromes. Collectively, the matrix-associated electron carriers discharge respiratory electrons from cells in multilayered biofilms to electron-accepting surfaces such as iron oxide coatings and electrodes poised at a metabolically oxidizable potential. The presence of pilus nanowires in the electroactive biofilms also promotes the immobilization and reduction of soluble metals, even when present at toxic concentrations. This review summarizes current knowledge about the composition of the electroactive biofilm matrix and the mechanisms that allow the wired Geobacter biofilms to generate electrical currents and participate in metal redox transformations.
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Affiliation(s)
- Gemma Reguera
- Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA
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35
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Miller A, Singh L, Wang L, Liu H. Linking internal resistance with design and operation decisions in microbial electrolysis cells. ENVIRONMENT INTERNATIONAL 2019; 126:611-618. [PMID: 30856448 DOI: 10.1016/j.envint.2019.02.056] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 01/16/2019] [Accepted: 02/21/2019] [Indexed: 06/09/2023]
Abstract
The distribution of internal resistance in most microbial electrolysis cells (MECs) remains unclear, which hinders the optimization and scaling up of the technology. In this study, a method for quantifying the effects of design and operation decisions on internal resistance was applied for the first time to MECs. In typical single chamber MECs with carbon cloth electrodes, the internal resistance was distributed as follows: 210 Ω cm2 for anode, 77 Ω cm2 for cathode, and 11 Ω cm2 M for solution. While varying the spacing of the electrodes (<1 cm) had little effect on MEC performance, inducing fluid motion between the electrodes decreased the internal resistance of all MEC components: 150 Ω cm2 for anode, 47 Ω cm2 for cathode, and 5.3 Ω cm2 M for solution. Adjusting the anode to cathode surface area ratio, to balance the internal resistance distribution, resulted in a significant improvement in performance (47 A/m2 current density, 3.7 L-H2/L-liquid volume/day). These results suggest that the quantification of the internal resistance distribution enables the efficient design and operation of MECs. The parameters obtained in this study were also capable of predicting the performance of MECs from some previous studies, demonstrating the effectiveness of this method.
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Affiliation(s)
- Andrew Miller
- Department of Biological and Ecological Engineering, Oregon State University, Corvallis, OR 97333, USA
| | - Lakhveer Singh
- Department of Biological and Ecological Engineering, Oregon State University, Corvallis, OR 97333, USA
| | - Luguang Wang
- Department of Biological and Ecological Engineering, Oregon State University, Corvallis, OR 97333, USA
| | - Hong Liu
- Department of Biological and Ecological Engineering, Oregon State University, Corvallis, OR 97333, USA.
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36
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Xu B, Wang G, Yang Q, Zheng Y. Hydrological buffering during groundwater acidification in rapidly industrializing alluvial plains. JOURNAL OF CONTAMINANT HYDROLOGY 2018; 218:19-33. [PMID: 30213456 DOI: 10.1016/j.jconhyd.2018.08.006] [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: 04/20/2017] [Revised: 07/30/2018] [Accepted: 08/23/2018] [Indexed: 06/08/2023]
Abstract
Shallow groundwater in alluvial plains is vulnerable to contamination due to infiltration of pollutants from anthropogenic activities. In the alluvial plain of the Yangtze River near Poyang Lake, a silicone monomer industrial park was found to discharge undisclosed amount of effluents containing high levels of hydrochloric acid and total dissolved solids into ponds and ditches that in turn, displayed characteristics of acidic water with high total dissolved solids. However, most shallow groundwater (n = 35, depth 5.5-22 m) collected from the alluvial aquifer downgradient of the industrial park contained low Cl- (< 59 mg/L). Only 4 groundwater samples showed high Cl- (59-790 mg/L) with two containing superlative levels (449 mg/L and 790 mg/L) located within a 50 m distance from the polluted ponds and ditches. In addition to hydrochemical data, modeling was used to explain why a highly vulnerable alluvial aquifer was not more contaminated when subjected to such intense point source pollution and to estimate the effluent discharge. Flow and solute transport modeling suggests that a hydrological buffering mechanism resulting from a topography driven groundwater outflow along the boundary between the Pleistocene (Qpw) and the Holocene (Qhl) aquifers where the polluted ponds and ditches are fortuitously located has restricted acid infiltration, with only a few percent of the estimated acid discharge in the amount of 1700-4200 tons per year entering the aquifer. Our model results show that pumping from the upland Qpw aquifer breaks this hydrological buffering much more easily than pumping from the downgradient Qhl aquifer, suggesting the vulnerability of this buffering mechanism thus compromising groundwater utilization in the future.
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Affiliation(s)
- Beiyi Xu
- School of Water Resources and Environment, State Key Laboratory of Biogeology & Environmental Geology, China University of Geosciences, Beijing 100083, China; Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York 10964, USA
| | - Guangcai Wang
- School of Water Resources and Environment, State Key Laboratory of Biogeology & Environmental Geology, China University of Geosciences, Beijing 100083, China
| | - Qiang Yang
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York 10964, USA
| | - Yan Zheng
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York 10964, USA; Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.
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37
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Zarabadi MP, Charette SJ, Greener J. Flow-Based Deacidification of Geobacter sulfurreducens
Biofilms Depends on Nutrient Conditions: a Microfluidic Bioelectrochemical Study. ChemElectroChem 2018. [DOI: 10.1002/celc.201800968] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Mir Pouyan Zarabadi
- Département de Chimie Faculté des sciences et de génie; Université Laval; Québec City, QC Canada
| | - Steve J. Charette
- Institut de Biologie Intégrative et des Systèmes; Université Laval; Québec City, QC Canada
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec; Québec City, QC Canada
- Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie; Université Laval; Québec City, QC Canada
| | - Jesse Greener
- Département de Chimie Faculté des sciences et de génie; Université Laval; Québec City, QC Canada
- CHU de Québec centre de recherche; Université Laval; 10 rue de l'Espinay Québec, QC Canada
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38
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Lebègue E, Louro RO, Barrière F. Electrochemical Detection of pH-Responsive Grafted Catechol and Immobilized Cytochrome c onto Lipid Deposit-Modified Glassy Carbon Surface. ACS OMEGA 2018; 3:9035-9042. [PMID: 31459037 PMCID: PMC6644398 DOI: 10.1021/acsomega.8b01425] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 07/31/2018] [Indexed: 06/02/2023]
Abstract
The electrochemical systems of both grafted catechol as a pH-responsive electrophore and immobilized cytochrome c as a model redox protein are detected by cyclic voltammetry at an optimized lipid deposit-modified glassy carbon electrode. The catechol covalent grafting is successfully performed by the one-pot/three-step electrochemical reduction of 3,4-dihydroxybenzenediazonium salts generated in situ from 4-nitrocatechol. The resulting glassy carbon electrode electrochemically modified by grafted catechol species is evaluated as an efficient electrochemical pH sensor. The optimized molar ratio for the lipid deposit, promoting cytochrome c electrochemical activity in solution onto glassy carbon electrode, is reached for the lipid mixture composed of 75% 1,2-dioleoyl-sn-glycero-3-phosphocholine and 25% cardiolipin. Cytochrome c immobilization into the optimized supported lipid deposit is efficiently achieved by cyclic voltammetry (10 cycles) recorded at the modified glassy carbon electrode in a cytochrome c solution. The pH-dependent redox response of the grafted catechol and that of the immobilized cytochrome c are finally detected at the same lipid-modified glassy carbon electrode without alteration of their structure and electrochemical properties in the pH range 5-9.
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Affiliation(s)
- Estelle Lebègue
- Univ Rennes, CNRS,
Institut des Sciences Chimiques de Rennes—UMR 6226, F-35000 Rennes, France
| | - Ricardo O. Louro
- Instituto de Tecnologia Química
e Biológica, António Xavier, Universidade NOVA de Lisboa, 2780-157 Oeiras, Portugal
| | - Frédéric Barrière
- Univ Rennes, CNRS,
Institut des Sciences Chimiques de Rennes—UMR 6226, F-35000 Rennes, France
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39
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Reguera G. Harnessing the power of microbial nanowires. Microb Biotechnol 2018; 11:979-994. [PMID: 29806247 PMCID: PMC6201914 DOI: 10.1111/1751-7915.13280] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 04/13/2018] [Accepted: 04/22/2018] [Indexed: 12/13/2022] Open
Abstract
The reduction of iron oxide minerals and uranium in model metal reducers in the genus Geobacter is mediated by conductive pili composed primarily of a structurally divergent pilin peptide that is otherwise recognized, processed and assembled in the inner membrane by a conserved Type IVa pilus apparatus. Electronic coupling among the peptides is promoted upon assembly, allowing the discharge of respiratory electrons at rates that greatly exceed the rates of cellular respiration. Harnessing the unique properties of these conductive appendages and their peptide building blocks in metal bioremediation will require understanding of how the pilins assemble to form a protein nanowire with specialized sites for metal immobilization. Also important are insights into how cells assemble the pili to make an electroactive matrix and grow on electrodes as biofilms that harvest electrical currents from the oxidation of waste organic substrates. Genetic engineering shows promise to modulate the properties of the peptide building blocks, protein nanowires and current‐harvesting biofilms for various applications. This minireview discusses what is known about the pilus material properties and reactions they catalyse and how this information can be harnessed in nanotechnology, bioremediation and bioenergy applications.
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Affiliation(s)
- Gemma Reguera
- Department of Microbiology and Molecular Genetics, Michigan State University, 567 Wilson Rd., Rm. 6190, East Lansing, MI, 48824, USA
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40
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Yates MD, Barr Engel S, Eddie BJ, Lebedev N, Malanoski AP, Tender LM. Redox-gradient driven electron transport in a mixed community anodic biofilm. FEMS Microbiol Ecol 2018; 94:4990946. [DOI: 10.1093/femsec/fiy081] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 05/01/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- Matthew D Yates
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC, 20375, USA
| | - Sarah Barr Engel
- Department of Civil and Environmental Engineering, Cornell University, 220 Hollister Hall, Ithaca, NY, 14853, USA
| | - Brian J Eddie
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC, 20375, USA
| | - Nikolai Lebedev
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC, 20375, USA
| | - Anthony P Malanoski
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC, 20375, USA
| | - Leonard M Tender
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC, 20375, USA
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41
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Lusk BG, Peraza I, Albal G, Marcus AK, Popat SC, Torres CI. pH Dependency in Anode Biofilms of Thermincola ferriacetica Suggests a Proton-Dependent Electrochemical Response. J Am Chem Soc 2018; 140:5527-5534. [DOI: 10.1021/jacs.8b01734] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Bradley G. Lusk
- Swette Center for Environmental Biotechnology, The Biodesign Institute at Arizona State University, P.O. Box 875701, Tempe, Arizona 85287, United States
- ScienceTheEarth, Mesa, Arizona 85201, United States
| | - Isaias Peraza
- Swette Center for Environmental Biotechnology, The Biodesign Institute at Arizona State University, P.O. Box 875701, Tempe, Arizona 85287, United States
| | - Gaurav Albal
- Swette Center for Environmental Biotechnology, The Biodesign Institute at Arizona State University, P.O. Box 875701, Tempe, Arizona 85287, United States
| | - Andrew K. Marcus
- Swette Center for Environmental Biotechnology, The Biodesign Institute at Arizona State University, P.O. Box 875701, Tempe, Arizona 85287, United States
| | - Sudeep C. Popat
- Department of Environmental Engineering and Earth Sciences, Clemson University, 342 Computer Court, Anderson, South Carolina 29625, United States
| | - Cesar I. Torres
- Swette Center for Environmental Biotechnology, The Biodesign Institute at Arizona State University, P.O. Box 875701, Tempe, Arizona 85287, United States
- School for Engineering of Matter, Transport and Energy, Arizona State University, 501 E Tyler Mall, Tempe, Arizona 85287, United States
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42
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Yates MD, Eddie BJ, Lebedev N, Kotloski NJ, Strycharz-Glaven SM, Tender LM. On the relationship between long-distance and heterogeneous electron transfer in electrode-grown Geobacter sulfurreducens biofilms. Bioelectrochemistry 2018; 119:111-118. [DOI: 10.1016/j.bioelechem.2017.09.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Revised: 09/12/2017] [Accepted: 09/14/2017] [Indexed: 02/05/2023]
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43
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Yin T, Li H, Su L, Liu S, Yuan C, Fu D. The catalytic effect of TiO 2 nanosheets on extracellular electron transfer of Shewanella loihica PV-4. Phys Chem Chem Phys 2018; 18:29871-29878. [PMID: 27759123 DOI: 10.1039/c6cp04509j] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Electron transfer kinetics of Shewanella loihica PV-4 at the up-growing TiO2 nanosheet (TiO2-NS) modified carbon paper (CP) electrode was investigated. The effect of TiO2-NSs, which speeds up the interfacial electron transfer of outer membrane c-type cytochromes (OMCs), was revealed for the first time. TiO2-NSs with a polar surface modified hydrophobic CP into super-hydrophilic TiO2-NS/CP. The favorable interaction between PV-4 and TiO2-NSs not only enhanced microbial adhesion, but also altered the redox nature of OMCs. The mid-point potential of OMCs at TiO2-NS/CP was shifted to a more negative potential, indicating a higher thermodynamic driving force for the protein to release electrons. Moreover, electron transfer from OMCs to TiO2-NSs was also benefited from the positive shift of flat-band potential Vfb owing to reduced pH at the electrode/microorganism interface, as well as good electrical conductivity of TiO2-NSs. As a result, the electron transfer rate constant ket of OMCs at the TiO2-NS/CP anode was about three times faster than that at the CP anode. The accelerated electron transfer kinetics as well as 15% increase of biomass together accounted for a 97% increase of the maximum output power density in the MFC. The result expanded our knowledge about the role of a designed TiO2 nanostructure in microbial electron transfer that can be applied in other bio-electrochemical systems.
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Affiliation(s)
- Tao Yin
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, 210096, People's Republic of China.
| | - Hui Li
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, 210096, People's Republic of China.
| | - Lin Su
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, 210096, People's Republic of China.
| | - Shuo Liu
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, 210096, People's Republic of China.
| | - Chunwei Yuan
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, 210096, People's Republic of China.
| | - Degang Fu
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, 210096, People's Republic of China. and Suzhou Key Laboratory of Environment and Biosafety, Suzhou, 215123, People's Republic of China and Jiangsu Key Laboratory for Biomaterials and Devices, Southeast University, Nanjing, 210096, People's Republic of China
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44
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Hou J, Liu Z, Zhou Y, Chen W, Li Y, Sang L. An experimental study of pH distributions within an electricity-producing biofilm by using pH microelectrode. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.08.101] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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45
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Santoro C, Arbizzani C, Erable B, Ieropoulos I. Microbial fuel cells: From fundamentals to applications. A review. JOURNAL OF POWER SOURCES 2017; 356:225-244. [PMID: 28717261 PMCID: PMC5465942 DOI: 10.1016/j.jpowsour.2017.03.109] [Citation(s) in RCA: 527] [Impact Index Per Article: 75.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 03/23/2017] [Indexed: 05/03/2023]
Abstract
In the past 10-15 years, the microbial fuel cell (MFC) technology has captured the attention of the scientific community for the possibility of transforming organic waste directly into electricity through microbially catalyzed anodic, and microbial/enzymatic/abiotic cathodic electrochemical reactions. In this review, several aspects of the technology are considered. Firstly, a brief history of abiotic to biological fuel cells and subsequently, microbial fuel cells is presented. Secondly, the development of the concept of microbial fuel cell into a wider range of derivative technologies, called bioelectrochemical systems, is described introducing briefly microbial electrolysis cells, microbial desalination cells and microbial electrosynthesis cells. The focus is then shifted to electroactive biofilms and electron transfer mechanisms involved with solid electrodes. Carbonaceous and metallic anode materials are then introduced, followed by an explanation of the electro catalysis of the oxygen reduction reaction and its behavior in neutral media, from recent studies. Cathode catalysts based on carbonaceous, platinum-group metal and platinum-group-metal-free materials are presented, along with membrane materials with a view to future directions. Finally, microbial fuel cell practical implementation, through the utilization of energy output for practical applications, is described.
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Affiliation(s)
- Carlo Santoro
- Department of Chemical and Biological Engineering, Center Micro-Engineered Materials (CMEM), University of New Mexico, 87106, Albuquerque, NM, USA
| | - Catia Arbizzani
- Department of Chemistry “Giacomo Ciamician”, University of Bologna, Via Selmi 2, 40126, Bologna, Italy
| | - Benjamin Erable
- University of Toulouse, CNRS, Laboratoire de Génie Chimique, CAMPUS INP – ENSIACET, 4 Allée Emile Monso, CS 84234, 31432, Toulouse Cedex 4, France
| | - Ioannis Ieropoulos
- Bristol BioEnergy Centre, Bristol Robotics Laboratory, T Block, University of the West of England, Frenchay Campus, Coldharbour Ln, Bristol, BS16 1QY, United Kingdom
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Liu Q, Liu B, Li W, Zhao X, Zuo W, Xing D. Impact of Ferrous Iron on Microbial Community of the Biofilm in Microbial Fuel Cells. Front Microbiol 2017. [PMID: 28638368 PMCID: PMC5461252 DOI: 10.3389/fmicb.2017.00920] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The performance of microbial electrochemical cells depends upon microbial community structure and metabolic activity of the electrode biofilms. Iron as a signal affects biofilm development and enrichment of exoelectrogenic bacteria. In this study, the effect of ferrous iron on microbial communities of the electrode biofilms in microbial fuel cells (MFCs) was investigated. Voltage production showed that ferrous iron of 100 μM facilitated MFC start-up compared to 150 μM, 200 μM, and without supplement of ferrous iron. However, higher concentration of ferrous iron had an inhibitive influence on current generation after 30 days of operation. Illumina Hiseq sequencing of 16S rRNA gene amplicons indicated that ferrous iron substantially changed microbial community structures of both anode and cathode biofilms. Principal component analysis showed that the response of microbial communities of the anode biofilms to higher concentration of ferrous iron was more sensitive. The majority of predominant populations of the anode biofilms in MFCs belonged to Geobacter, which was different from the populations of the cathode biofilms. An obvious shift of community structures of the cathode biofilms occurred after ferrous iron addition. This study implied that ferrous iron influenced the power output and microbial community of MFCs.
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Affiliation(s)
- Qian Liu
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of TechnologyHarbin, China
| | - Bingfeng Liu
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of TechnologyHarbin, China
| | - Wei Li
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of TechnologyHarbin, China
| | - Xin Zhao
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of TechnologyHarbin, China
| | - Wenjing Zuo
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of TechnologyHarbin, China
| | - Defeng Xing
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of TechnologyHarbin, China
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Floc Formation Reduces the pH Stress Experienced by Microorganisms Living in Alkaline Environments. Appl Environ Microbiol 2017; 83:AEM.02985-16. [PMID: 28087527 DOI: 10.1128/aem.02985-16] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 01/05/2017] [Indexed: 11/20/2022] Open
Abstract
The survival of microorganisms within a cementitious geological disposal facility for radioactive wastes heavily depends on their ability to survive the calcium-dominated, hyperalkaline conditions resulting from the dissolution of the cementitious materials. The results from this study show that the formation of flocs, composed of a complex mixture of extracellular polymeric substances (EPS), provides protection against alkaline pH values up to 13.0. The flocs were dominated by Alishewanella and Dietzia spp., producing a mannose-rich carbohydrate fraction incorporating extracellular DNA, resulting in Ca2+ sequestration. EPS provided a ∼10-μm thick layer around the cells within the center of the flocs, which were capable of growth at pH values of 11.0 and 11.5, maintaining internal pH values of 10.4 and 10.7, respectively. Microorganisms survived at a pH of 12.0, where an internal floc pH of 11.6 was observed, as was a reduced associated biomass. We observed limited floc survival (<2 weeks) at a pH of 13.0. This study demonstrates that flocs maintain lower internal pHs in response to the hyperalkaline conditions expected to occur within a cementitious geological disposal facility for radioactive wastes and indicates that floc communities within such a facility can survive at pHs up to 12.0.IMPORTANCE The role of extracellular polymeric substances (EPS) in the survival of microorganisms in hyperalkaline conditions is poorly understood. Here, we present the taxonomy, morphology, and chemical characteristics of an EPS-based microbial floc, formed by a consortium isolated from an anthropogenic hyperalkaline site. Short-term (<2 weeks) survival of the flocs at a pH of 13 was observed, with indefinite survival observed at a pH of 12.0. Measurements from micro-pH electrodes (10-μm-diameter tip) demonstrated that flocs maintain lower internal pHs in response to hyperalkaline conditions (pH 11.0, 11.5, and 12.0), demonstrating that floc formation and EPS production are survival strategies under hyperalkaline conditions. The results indicate how microbial communities may survive and propagate within the hyperalkaline environment that is expected to prevail in a cementitious geological disposal facility for radioactive wastes; the results are also relevant to the wider extremophile community.
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Ha PT, Lindemann SR, Shi L, Dohnalkova AC, Fredrickson JK, Madigan MT, Beyenal H. Syntrophic anaerobic photosynthesis via direct interspecies electron transfer. Nat Commun 2017; 8:13924. [PMID: 28067226 PMCID: PMC5227917 DOI: 10.1038/ncomms13924] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 11/11/2016] [Indexed: 11/29/2022] Open
Abstract
Microbial phototrophs, key primary producers on Earth, use H2O, H2, H2S and other reduced inorganic compounds as electron donors. Here we describe a form of metabolism linking anoxygenic photosynthesis to anaerobic respiration that we call ‘syntrophic anaerobic photosynthesis'. We show that photoautotrophy in the green sulfur bacterium Prosthecochloris aestaurii can be driven by either electrons from a solid electrode or acetate oxidation via direct interspecies electron transfer from a heterotrophic partner bacterium, Geobacter sulfurreducens. Photosynthetic growth of P. aestuarii using reductant provided by either an electrode or syntrophy is robust and light-dependent. In contrast, P. aestuarii does not grow in co-culture with a G. sulfurreducens mutant lacking a trans-outer membrane porin-cytochrome protein complex required for direct intercellular electron transfer. Syntrophic anaerobic photosynthesis is therefore a carbon cycling process that could take place in anoxic environments. This process could be exploited for biotechnological applications, such as waste treatment and bioenergy production, using engineered phototrophic microbial communities. Direct interspecies electron transfer has been shown in methane-producing communities, but it is unknown how widespread this mechanism is. Here, Ha et al. show that anoxygenic photosynthesis can be driven by direct electron transfer from a heterotrophic partner bacterium.
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Affiliation(s)
- Phuc T Ha
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington 99164, USA
| | - Stephen R Lindemann
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99354, USA
| | - Liang Shi
- Department of Biological Sciences and Technology, School of Environmental Studies, China University of Geoscience, Wuhan, Hubei 430074, China
| | - Alice C Dohnalkova
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, USA
| | - James K Fredrickson
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99354, USA
| | - Michael T Madigan
- Department of Microbiology, Southern Illinois University, Carbondale, Illinois 62901, USA
| | - Haluk Beyenal
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington 99164, USA
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Lewis AJ, Borole AP. Understanding the impact of flow rate and recycle on the conversion of a complex biorefinery stream using a flow-through microbial electrolysis cell. Biochem Eng J 2016. [DOI: 10.1016/j.bej.2016.06.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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50
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Lusk BG, Parameswaran P, Popat SC, Rittmann BE, Torres CI. The effect of pH and buffer concentration on anode biofilms of Thermincola ferriacetica. Bioelectrochemistry 2016; 112:47-52. [DOI: 10.1016/j.bioelechem.2016.07.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 07/17/2016] [Accepted: 07/18/2016] [Indexed: 11/16/2022]
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