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Xu P, Liu H, Liu C, Zhu G. Syntrophic methane production from volatile fatty acids: Focus on interspecies electron transfer. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174410. [PMID: 38960157 DOI: 10.1016/j.scitotenv.2024.174410] [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: 03/22/2024] [Revised: 06/28/2024] [Accepted: 06/29/2024] [Indexed: 07/05/2024]
Abstract
Methane is a renewable biomass energy source produced via anaerobic digestion (AD). Interspecies electron transfer (IET) between methanogens and syntrophic bacteria is crucial for mitigating energy barriers in this process. Understanding IET is essential for enhancing the efficiency of syntrophic methanogenesis in anaerobic digestion. Interspecies electron transfer mechanisms include interspecies H2/formate transfer, direct interspecies electron transfer (DIET), and electron-shuttle-mediated transfer. This review summarizes the mechanisms, developments, and research gaps in IET pathways. Interspecies H2/formate transfer requires strict control of low H2 partial pressure and involves complex enzymatic reactions. In contrast, DIET enhances the electron transfer efficiency and process stability. Conductive materials and key microorganisms can be modulated to stimulate the DIET. Electron shuttles (ES) allow microorganisms to interact with extracellular electron acceptors without direct contact; however, their efficiency depends on various factors. Future studies should elucidate the key functional groups, metabolic pathways, and regulatory mechanisms of IET to guide the optimization of AD processes for efficient renewable energy production.
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Affiliation(s)
- Panhui Xu
- School of Chemistry and Life Resources, Renmin University of China, Beijing 100872, China
| | - Haichen Liu
- Shanghai Investigation, Design & Research Institute Co., Ltd., 200080, China
| | - Chong Liu
- The 101 Research Institute, Ministry of Civil Affairs of the People's Republic of China, Beijing 100070, China.
| | - Gefu Zhu
- School of Chemistry and Life Resources, Renmin University of China, Beijing 100872, China
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2
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Guberman-Pfeffer MJ. To be or not to be a cytochrome: electrical characterizations are inconsistent with Geobacter cytochrome 'nanowires'. Front Microbiol 2024; 15:1397124. [PMID: 38633696 PMCID: PMC11021709 DOI: 10.3389/fmicb.2024.1397124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Accepted: 03/21/2024] [Indexed: 04/19/2024] Open
Abstract
Geobacter sulfurreducens profoundly shapes Earth's biogeochemistry by discharging respiratory electrons to minerals and other microbes through filaments of a two-decades-long debated identity. Cryogenic electron microscopy has revealed filaments of redox-active cytochromes, but the same filaments have exhibited hallmarks of organic metal-like conductivity under cytochrome denaturing/inhibiting conditions. Prior structure-based calculations and kinetic analyses on multi-heme proteins are synthesized herein to propose that a minimum of ~7 cytochrome 'nanowires' can carry the respiratory flux of a Geobacter cell, which is known to express somewhat more (≥20) filaments to increase the likelihood of productive contacts. By contrast, prior electrical and spectroscopic structural characterizations are argued to be physiologically irrelevant or physically implausible for the known cytochrome filaments because of experimental artifacts and sample impurities. This perspective clarifies our mechanistic understanding of physiological metal-microbe interactions and advances synthetic biology efforts to optimize those interactions for bioremediation and energy or chemical production.
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Nguyen HTT, Le GTH, Park SG, Jadhav DA, Le TTQ, Kim H, Vinayak V, Lee G, Yoo K, Song YC, Chae KJ. Optimizing electrochemically active microorganisms as a key player in the bioelectrochemical system: Identification methods and pathways to large-scale implementation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 914:169766. [PMID: 38181955 DOI: 10.1016/j.scitotenv.2023.169766] [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: 10/20/2023] [Revised: 12/15/2023] [Accepted: 12/28/2023] [Indexed: 01/07/2024]
Abstract
The rapid global economic growth driven by industrialization and population expansion has resulted in significant issues, including reliance on fossil fuels, energy scarcity, water crises, and environmental emissions. To address these issues, bioelectrochemical systems (BES) have emerged as a dual-purpose solution, harnessing electrochemical processes and the capabilities of electrochemically active microorganisms (EAM) to simultaneously recover energy and treat wastewater. This review examines critical performance factors in BES, including inoculum selection, pretreatment methods, electrodes, and operational conditions. Further, authors explore innovative approaches to suppress methanogens and simultaneously enhance the EAM in mixed cultures. Additionally, advanced techniques for detecting EAM are discussed. The rapid detection of EAM facilitates the selection of suitable inoculum sources and optimization of enrichment strategies in BESs. This optimization is essential for facilitating the successful scaling up of BES applications, contributing substantially to the realization of clean energy and sustainable wastewater treatment. This analysis introduces a novel viewpoint by amalgamating contemporary research on the selective enrichment of EAM in mixed cultures. It encompasses identification and detection techniques, along with methodologies tailored for the selective enrichment of EAM, geared explicitly toward upscaling applications in BES.
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Affiliation(s)
- Ha T T Nguyen
- Department of Environmental Engineering, College of Ocean Science and Engineering, Korea Maritime and Ocean University, 727 Taejong-ro, Yeongdo-gu, Busan 49112, Republic of Korea; Department of Convergence Study on the Ocean Science and Technology, Ocean Science and Technology School (OST), Korea Maritime and Ocean University, 727 Taejong-ro, Yeongdo-gu, Busan 49112, Republic of Korea
| | - Giang T H Le
- Department of Environmental Engineering, College of Ocean Science and Engineering, Korea Maritime and Ocean University, 727 Taejong-ro, Yeongdo-gu, Busan 49112, Republic of Korea; Interdisciplinary Major of Ocean Renewable Energy Engineering, Korea Maritime and Ocean University, 727 Taejong-ro, Yeongdo-gu, Busan 49112, Republic of Korea
| | - Sung-Gwan Park
- Department of Environmental Engineering, College of Ocean Science and Engineering, Korea Maritime and Ocean University, 727 Taejong-ro, Yeongdo-gu, Busan 49112, Republic of Korea; Interdisciplinary Major of Ocean Renewable Energy Engineering, Korea Maritime and Ocean University, 727 Taejong-ro, Yeongdo-gu, Busan 49112, Republic of Korea
| | - Dipak A Jadhav
- Department of Environmental Engineering, College of Ocean Science and Engineering, Korea Maritime and Ocean University, 727 Taejong-ro, Yeongdo-gu, Busan 49112, Republic of Korea; Interdisciplinary Major of Ocean Renewable Energy Engineering, Korea Maritime and Ocean University, 727 Taejong-ro, Yeongdo-gu, Busan 49112, Republic of Korea
| | - Trang T Q Le
- Department of Environmental Engineering, College of Ocean Science and Engineering, Korea Maritime and Ocean University, 727 Taejong-ro, Yeongdo-gu, Busan 49112, Republic of Korea; Interdisciplinary Major of Ocean Renewable Energy Engineering, Korea Maritime and Ocean University, 727 Taejong-ro, Yeongdo-gu, Busan 49112, Republic of Korea
| | - Hyunsu Kim
- Department of Environmental Engineering, College of Ocean Science and Engineering, Korea Maritime and Ocean University, 727 Taejong-ro, Yeongdo-gu, Busan 49112, Republic of Korea; Interdisciplinary Major of Ocean Renewable Energy Engineering, Korea Maritime and Ocean University, 727 Taejong-ro, Yeongdo-gu, Busan 49112, Republic of Korea
| | - Vandana Vinayak
- Diatom Nanoengineering and Metabolism Laboratory (DNM), School of Applied Science, Dr. Hari Singh Gour Central University, Sagar, MP 470003, India
| | - Gihan Lee
- Department of Environmental Engineering, College of Ocean Science and Engineering, Korea Maritime and Ocean University, 727 Taejong-ro, Yeongdo-gu, Busan 49112, Republic of Korea; Interdisciplinary Major of Ocean Renewable Energy Engineering, Korea Maritime and Ocean University, 727 Taejong-ro, Yeongdo-gu, Busan 49112, Republic of Korea
| | - Keunje Yoo
- Department of Environmental Engineering, College of Ocean Science and Engineering, Korea Maritime and Ocean University, 727 Taejong-ro, Yeongdo-gu, Busan 49112, Republic of Korea; Interdisciplinary Major of Ocean Renewable Energy Engineering, Korea Maritime and Ocean University, 727 Taejong-ro, Yeongdo-gu, Busan 49112, Republic of Korea
| | - Young-Chae Song
- Department of Environmental Engineering, College of Ocean Science and Engineering, Korea Maritime and Ocean University, 727 Taejong-ro, Yeongdo-gu, Busan 49112, Republic of Korea; Interdisciplinary Major of Ocean Renewable Energy Engineering, Korea Maritime and Ocean University, 727 Taejong-ro, Yeongdo-gu, Busan 49112, Republic of Korea.
| | - Kyu-Jung Chae
- Department of Environmental Engineering, College of Ocean Science and Engineering, Korea Maritime and Ocean University, 727 Taejong-ro, Yeongdo-gu, Busan 49112, Republic of Korea; Interdisciplinary Major of Ocean Renewable Energy Engineering, Korea Maritime and Ocean University, 727 Taejong-ro, Yeongdo-gu, Busan 49112, Republic of Korea.
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You Z, Li J, Wang Y, Wu D, Li F, Song H. Advances in mechanisms and engineering of electroactive biofilms. Biotechnol Adv 2023; 66:108170. [PMID: 37148984 DOI: 10.1016/j.biotechadv.2023.108170] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 03/22/2023] [Accepted: 05/02/2023] [Indexed: 05/08/2023]
Abstract
Electroactive biofilms (EABs) are electroactive microorganisms (EAMs) encased in conductive polymers that are secreted by EAMs and formed by the accumulation and cross-linking of extracellular polysaccharides, proteins, nucleic acids, lipids, and other components. EABs are present in the form of multicellular aggregates and play a crucial role in bioelectrochemical systems (BESs) for diverse applications, including biosensors, microbial fuel cells for renewable bioelectricity production and remediation of wastewaters, and microbial electrosynthesis of valuable chemicals. However, naturally occurred EABs are severely limited owing to their low electrical conductivity that seriously restrict the electron transfer efficiency and practical applications. In the recent decade, synthetic biology strategies have been adopted to elucidate the regulatory mechanisms of EABs, and to enhance the formation and electrical conductivity of EABs. Based on the formation of EABs and extracellular electron transfer (EET) mechanisms, the synthetic biology-based engineering strategies of EABs are summarized and reviewed as follows: (i) Engineering the structural components of EABs, including strengthening the synthesis and secretion of structural elements such as polysaccharides, eDNA, and structural proteins, to improve the formation of biofilms; (ii) Enhancing the electron transfer efficiency of EAMs, including optimizing the distribution of c-type cytochromes and conducting nanowire assembly to promote contact-based EET, and enhancing electron shuttles' biosynthesis and secretion to promote shuttle-mediated EET; (iii) Incorporating intracellular signaling molecules in EAMs, including quorum sensing systems, secondary messenger systems, and global regulatory systems, to increase the electron transfer flux in EABs. This review lays a foundation for the design and construction of EABs for diverse BES applications.
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Affiliation(s)
- Zixuan You
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Jianxun Li
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100093, China
| | - Yuxuan Wang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Deguang Wu
- Department of Brewing Engineering, Moutai Institute, Luban Ave, Renhuai 564507, Guizhou, PR China
| | - Feng Li
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
| | - Hao Song
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
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5
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Enhancing Biodegradation of Pyridine with Trehalose Lipid in Rhodococcus pyridinivorans sp. Strain HR-1-Inoculated Microbial Fuel Cell. FERMENTATION 2023. [DOI: 10.3390/fermentation9020133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
A Gram-positive exoelectrogen Rhodococcus pyridinivorans sp. strain HR-1 was cultivated from leachate-fed microbial fuel cell (MFC) to study the biodegradation effect of pyridine. In the comparison with mixed cultured MFC, HR-1 presented a remarkable electrical capacity with a maximum output of 4.33 W/m3 under 30 °C in neutral anolyte with 1 g/L acetate as a substrate. Further, HR-1 demonstrated the environmental resistance as a Gram-positive strain. Microbial metabolism was evident at pH between 5–9 and temperature in the range of 20–40 °C, whereas optimal condition for pyridine degradation was observed at 30 °C. This is the first study reporting the degradation of pyridine in the bio-electrochemical system that achieved a 42% ± 5% degradation rate in a full operation cycle at 2 g/L of the concentration. Considering the nonnegligible internal resistance of HR-1-inoculated MFC, trehalose lipid was also introduced as a bio-surfactant to reduce the charge transfer obstacle between the microbes and the electrodes. The surface morphology illustrated that the strain had a plump shape with a high specific area. Accordingly, bio-surfactant addition promoted the anode biomass (1.2 ± 0.1 mg/cm2 to 1.7 ± 0.2 mg/cm2) and achieved a higher degradation rate (68% ± 4%). The feasibility of electrochemical disposal on pyridine and eminent adaptability of strain sp. HR-1 as a Gram-positive exoelectrogen makes MFC a practical approach for real application.
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Wang H, Qi X, Zhang L, Zhang X, Xu P, Wang X. Efficient bioelectricity generation and carbazole biodegradation using an electrochemically active bacterium Sphingobium yanoikuyae XLDN2-5. CHEMOSPHERE 2022; 307:135986. [PMID: 35970217 DOI: 10.1016/j.chemosphere.2022.135986] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 07/04/2022] [Accepted: 08/06/2022] [Indexed: 06/15/2023]
Abstract
Carbazole and its derivatives are polycyclic aromatic heterocycles with unusual toxicity and mutagenicity. However, disposal of these polycyclic aromatic heterocycles remains a significant challenge. This study focused on efficient resource recovery from carbazole using an obligate aerobe, Sphingobium yanoikuyae XLDN2-5, in microbial fuel cells (MFCs). S. yanoikuyae XLDN2-5 successfully achieved carbazole degradation and simultaneously electricity generation in MFCs with a maximum power density of 496.8 mW m-2 and carbazole degradation rate of 100%. It is the first time that S. yanoikuyae XLDN2-5 was discovered as an electrochemically active bacterium with high extracellular electron transfer (EET) capability. Redox mediator analysis indicated that no self-produced redox mediators were found for S. yanoikuyae XLDN2-5 under analysis conditions, and the exogenous redox mediators used in this study did not promote its EET. The nanowires produced by S. yanoikuyae XLDN2-5 cells were found in the biofilm by morphology characterization and the growth process of the nanowires was consistent with the discharge process of the MFC. Conductivity determination further verified that the nanowires produced by S. yanoikuyae XLDN2-5 cells were electrically conductive. Based on these results, it is speculated that S. yanoikuyae XLDN2-5 may mainly utilize conductive nanowires produced by itself rather than redox mediators to meet the requirements of normal energy metabolism when it grows in the low dissolved oxygen zone of the anodic biofilm. These novel findings on the EET mechanism of S. yanoikuyae XLDN2-5 lay a foundation for further exploration of polycyclic aromatic heterocyclic pollutants treatment in electrochemical devices, which may create new biotechnology processes for these pollutants control.
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Affiliation(s)
- Huimin Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, PR China; Department of Microbiology, College of Life Science, Key Laboratory for Agriculture Microbiology, Shandong Agricultural University, Taian, 271018, PR China
| | - Xiaoyan Qi
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, PR China
| | - Lei Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, PR China
| | - Xueli Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, PR China
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, PR China
| | - Xia Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, PR China.
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7
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The periodic table of photosynthetic purple non-sulfur bacteria: intact cell-metal ions interactions. Photochem Photobiol Sci 2021; 21:101-111. [PMID: 34748197 DOI: 10.1007/s43630-021-00116-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 10/12/2021] [Indexed: 10/19/2022]
Abstract
Photosynthetic purple non-sulfur bacteria (PNB) have been widely utilized as model organisms to study bacterial photosynthesis. More recently, the remarkable resistance of these microorganisms to several metals ions called particular interest. As a result, several research efforts were directed toward clarifying the interactions of metal ions with PNB. The mechanisms of metal ions active uptake and bioabsorption have been studied in detail, unveiling that PNB enable harvesting and removing various toxic ions, thus fostering applications in environmental remediation. Herein, we present the most important achievements in the understanding of intact cell-metal ions interactions and the approaches utilized to study such processes. Following, the application of PNB-metal ions interactions toward metal removal from contaminated environments is presented. Finally, the possible coupling of PNB with abiotic electrodes to obtain biohybrid electrochemical systems is proposed as a sustainable pathway to tune and enhance metal removal and monitoring.
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8
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McCuskey SR, Chatsirisupachai J, Zeglio E, Parlak O, Panoy P, Herland A, Bazan GC, Nguyen TQ. Current Progress of Interfacing Organic Semiconducting Materials with Bacteria. Chem Rev 2021; 122:4791-4825. [PMID: 34714064 DOI: 10.1021/acs.chemrev.1c00487] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Microbial bioelectronics require interfacing microorganisms with electrodes. The resulting abiotic/biotic platforms provide the basis of a range of technologies, including energy conversion and diagnostic assays. Organic semiconductors (OSCs) provide a unique strategy to modulate the interfaces between microbial systems and external electrodes, thereby improving the performance of these incipient technologies. In this review, we explore recent progress in the field on how OSCs, and related materials capable of charge transport, are being used within the context of microbial systems, and more specifically bacteria. We begin by examining the electrochemical communication modes in bacteria and the biological basis for charge transport. Different types of synthetic organic materials that have been designed and synthesized for interfacing and interrogating bacteria are discussed next, followed by the most commonly used characterization techniques for evaluating transport in microbial, synthetic, and hybrid systems. A range of applications is subsequently examined, including biological sensors and energy conversion systems. The review concludes by summarizing what has been accomplished so far and suggests future design approaches for OSC bioelectronics materials and technologies that hybridize characteristic properties of microbial and OSC systems.
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Affiliation(s)
- Samantha R McCuskey
- Department of Chemistry, National University of Singapore, Singapore 119077, Singapore
| | - Jirat Chatsirisupachai
- Center for Polymers and Organic Solids & Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States.,Department of Materials Science and Engineering, School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Wangchan, Rayong 21210, Thailand
| | - Erica Zeglio
- Division of Micro and Nanosystems, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, Stockholm 17177, Sweden
| | - Onur Parlak
- Dermatology and Venereology Division, Department of Medicine(Solna), Karolinska Institute, Stockholm 17177, Sweden.,AIMES Center of Integrated Medical and Engineering Sciences, Department of Neuroscience, Karolinska Institute, Stockholm 17177, Sweden
| | - Patchareepond Panoy
- Center for Polymers and Organic Solids & Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States.,Department of Materials Science and Engineering, School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Wangchan, Rayong 21210, Thailand
| | - Anna Herland
- Division of Micro and Nanosystems, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, Stockholm 17177, Sweden.,AIMES Center of Integrated Medical and Engineering Sciences, Department of Neuroscience, Karolinska Institute, Stockholm 17177, Sweden
| | - Guillermo C Bazan
- Department of Chemistry, National University of Singapore, Singapore 119077, Singapore
| | - Thuc-Quyen Nguyen
- Center for Polymers and Organic Solids & Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
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Prados MB, Lescano M, Porzionato N, Curutchet G. Wiring Up Along Electrodes for Biofilm Formation. Front Microbiol 2021; 12:726251. [PMID: 34526980 PMCID: PMC8435748 DOI: 10.3389/fmicb.2021.726251] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 08/09/2021] [Indexed: 11/13/2022] Open
Abstract
Millimeter-length cables of bacteria were discovered growing along a graphite-rod electrode serving as an anode of a microbial electrolysis cell (MEC). The MEC had been inoculated with a culture of Fe-reducing microorganisms enriched from a polluted river sediment (Reconquista river, Argentina) and was operated at laboratory controlled conditions for 18 days at an anode poised potential of 240 mV (vs. Ag/AgCl), followed by 23 days at 480 mV (vs. Ag/AgCl). Anode samples were collected for scanning electron microscopy, phylogenetic and electrochemical analyses. The cables were composed of a succession of bacteria covered by a membranous sheath and were distinct from the known "cable-bacteria" (family Desulfobulbaceae). Apparently, the formation of the cables began with the interaction of the cells via nanotubes mostly located at the cell poles. The cables seemed to be further widened by the fusion between them. 16S rRNA gene sequence analysis confirmed the presence of a microbial community composed of six genera, including Shewanella, a well-characterized electrogenic bacteria. The formation of the cables might be a way of colonizing a polarized surface, as determined by the observation of electrodes extracted at different times of MEC operation. Since the cables of bacteria were distinct from any previously described, the results suggest that bacteria capable of forming cables are more diverse in nature than already thought. This diversity might render different electrical properties that could be exploited for various applications.
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Affiliation(s)
- María Belén Prados
- Instituto de Energía y Desarrollo Sustentable, Centro Atómico Bariloche, Comisión Nacional de Energía Atómica, Buenos Aires, Argentina
| | - Mariela Lescano
- Instituto de Energía y Desarrollo Sustentable, Centro Atómico Bariloche, Comisión Nacional de Energía Atómica, Buenos Aires, Argentina
| | - Natalia Porzionato
- Instituto de Investigaciones e Ingeniería Ambiental y Escuela de Ciencia y Tecnología, Universidad Nacional de San Martín, Buenos Aires, Argentina
| | - Gustavo Curutchet
- Instituto de Investigaciones e Ingeniería Ambiental y Escuela de Ciencia y Tecnología, Universidad Nacional de San Martín, Buenos Aires, Argentina
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Sokolova DS, Semenova EM, Grouzdev DS, Bidzhieva SK, Babich TL, Loiko NG, Ershov AP, Kadnikov VV, Beletsky AV, Mardanov AV, Zhaparov NS, Nazina TN. Sulfidogenic Microbial Communities of the Uzen High-Temperature Oil Field in Kazakhstan. Microorganisms 2021; 9:1818. [PMID: 34576714 PMCID: PMC8467725 DOI: 10.3390/microorganisms9091818] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 08/20/2021] [Accepted: 08/24/2021] [Indexed: 11/16/2022] Open
Abstract
Application of seawater for secondary oil recovery stimulates the development of sulfidogenic bacteria in the oil field leading to microbially influenced corrosion of steel equipment, oil souring, and environmental issues. The aim of this work was to investigate potential sulfide producers in the high-temperature Uzen oil field (Republic of Kazakhstan) exploited with seawater flooding and the possibility of suppressing growth of sulfidogens in both planktonic and biofilm forms. Approaches used in the study included 16S rRNA and dsrAB gene sequencing, scanning electron microscopy, and culture-based techniques. Thermophilic hydrogenotrophic methanogens of the genus Methanothermococcus (phylum Euryarchaeota) predominated in water from the zone not affected by seawater flooding. Methanogens were accompanied by fermentative bacteria of the genera Thermovirga, Defliviitoga, Geotoga, and Thermosipho (phylum Thermotogae), which are potential thiosulfate- or/and sulfur-reducers. In the sulfate- and sulfide-rich formation water, the share of Desulfonauticus sulfate-reducing bacteria (SRB) increased. Thermodesulforhabdus, Thermodesulfobacterium, Desulfotomaculum, Desulfovibrio, and Desulfoglaeba were also detected. Mesophilic denitrifying bacteria of the genera Marinobacter, Halomonas, and Pelobacter inhabited the near-bottom zone of injection wells. Nitrate did not suppress sulfidogenesis in mesophilic enrichments because denitrifiers reduced nitrate to dinitrogen; however, thermophilic denitrifiers produced nitrite, an inhibitor of SRB. Enrichments and a pure culture Desulfovibrio alaskensis Kaz19 formed biofilms highly resistant to biocides. Our results suggest that seawater injection and temperature of the environment determine the composition and functional activity of prokaryotes in the Uzen oil field.
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Affiliation(s)
- Diyana S. Sokolova
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (D.S.S.); (E.M.S.); (S.K.B.); (T.L.B.); (N.G.L.); (A.P.E.)
| | - Ekaterina M. Semenova
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (D.S.S.); (E.M.S.); (S.K.B.); (T.L.B.); (N.G.L.); (A.P.E.)
| | | | - Salimat K. Bidzhieva
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (D.S.S.); (E.M.S.); (S.K.B.); (T.L.B.); (N.G.L.); (A.P.E.)
| | - Tamara L. Babich
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (D.S.S.); (E.M.S.); (S.K.B.); (T.L.B.); (N.G.L.); (A.P.E.)
| | - Nataliya G. Loiko
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (D.S.S.); (E.M.S.); (S.K.B.); (T.L.B.); (N.G.L.); (A.P.E.)
| | - Alexey P. Ershov
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (D.S.S.); (E.M.S.); (S.K.B.); (T.L.B.); (N.G.L.); (A.P.E.)
| | - Vitaly V. Kadnikov
- Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (V.V.K.); (A.V.B.); (A.V.M.)
| | - Alexey V. Beletsky
- Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (V.V.K.); (A.V.B.); (A.V.M.)
| | - Andrey V. Mardanov
- Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (V.V.K.); (A.V.B.); (A.V.M.)
| | - Nurlan S. Zhaparov
- Branch of the Limited Liability Partnership “KazMunaiGas Engineering”, Aktau 130000, Kazakhstan;
| | - Tamara N. Nazina
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia; (D.S.S.); (E.M.S.); (S.K.B.); (T.L.B.); (N.G.L.); (A.P.E.)
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11
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Fritts RK, McCully AL, McKinlay JB. Extracellular Metabolism Sets the Table for Microbial Cross-Feeding. Microbiol Mol Biol Rev 2021; 85:e00135-20. [PMID: 33441489 PMCID: PMC7849352 DOI: 10.1128/mmbr.00135-20] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The transfer of nutrients between cells, or cross-feeding, is a ubiquitous feature of microbial communities with emergent properties that influence our health and orchestrate global biogeochemical cycles. Cross-feeding inevitably involves the externalization of molecules. Some of these molecules directly serve as cross-fed nutrients, while others can facilitate cross-feeding. Altogether, externalized molecules that promote cross-feeding are diverse in structure, ranging from small molecules to macromolecules. The functions of these molecules are equally diverse, encompassing waste products, enzymes, toxins, signaling molecules, biofilm components, and nutrients of high value to most microbes, including the producer cell. As diverse as the externalized and transferred molecules are the cross-feeding relationships that can be derived from them. Many cross-feeding relationships can be summarized as cooperative but are also subject to exploitation. Even those relationships that appear to be cooperative exhibit some level of competition between partners. In this review, we summarize the major types of actively secreted, passively excreted, and directly transferred molecules that either form the basis of cross-feeding relationships or facilitate them. Drawing on examples from both natural and synthetic communities, we explore how the interplay between microbial physiology, environmental parameters, and the diverse functional attributes of extracellular molecules can influence cross-feeding dynamics. Though microbial cross-feeding interactions represent a burgeoning field of interest, we may have only begun to scratch the surface.
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Affiliation(s)
- Ryan K Fritts
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | | | - James B McKinlay
- Department of Biology, Indiana University, Bloomington, Indiana, USA
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12
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Gavrilov SN, Zavarzina DG, Elizarov IM, Tikhonova TV, Dergousova NI, Popov VO, Lloyd JR, Knight D, El-Naggar MY, Pirbadian S, Leung KM, Robb FT, Zakhartsev MV, Bretschger O, Bonch-Osmolovskaya EA. Novel Extracellular Electron Transfer Channels in a Gram-Positive Thermophilic Bacterium. Front Microbiol 2021; 11:597818. [PMID: 33505370 PMCID: PMC7829351 DOI: 10.3389/fmicb.2020.597818] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Accepted: 12/04/2020] [Indexed: 12/22/2022] Open
Abstract
Biogenic transformation of Fe minerals, associated with extracellular electron transfer (EET), allows microorganisms to exploit high-potential refractory electron acceptors for energy generation. EET-capable thermophiles are dominated by hyperthermophilic archaea and Gram-positive bacteria. Information on their EET pathways is sparse. Here, we describe EET channels in the thermophilic Gram-positive bacterium Carboxydothermus ferrireducens that drive exoelectrogenesis and rapid conversion of amorphous mineral ferrihydrite to large magnetite crystals. Microscopic studies indicated biocontrolled formation of unusual formicary-like ultrastructure of the magnetite crystals and revealed active colonization of anodes in bioelectrochemical systems (BESs) by C. ferrireducens. The internal structure of micron-scale biogenic magnetite crystals is reported for the first time. Genome analysis and expression profiling revealed three constitutive c-type multiheme cytochromes involved in electron exchange with ferrihydrite or an anode, sharing insignificant homology with previously described EET-related cytochromes thus representing novel determinants of EET. Our studies identify these cytochromes as extracellular and reveal potentially novel mechanisms of cell-to-mineral interactions in thermal environments.
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Affiliation(s)
- Sergey N Gavrilov
- Winogradsky Institute of Microbiology, FRC Biotechnology Russian Academy of Sciences, Moscow, Russia
| | - Daria G Zavarzina
- Winogradsky Institute of Microbiology, FRC Biotechnology Russian Academy of Sciences, Moscow, Russia
| | - Ivan M Elizarov
- Winogradsky Institute of Microbiology, FRC Biotechnology Russian Academy of Sciences, Moscow, Russia
| | - Tamara V Tikhonova
- Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Natalia I Dergousova
- Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Vladimir O Popov
- Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia.,Kurchatov Complex NBICS-Technologies, National Research Center "Kurchatov Institute," Moscow, Russia
| | - Jonathan R Lloyd
- Dalton Nuclear Institute, FSE Research Institutes, The University of Manchester, Manchester, United Kingdom
| | - David Knight
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | | | - Sahand Pirbadian
- University of Southern California, Los Angeles, CA, United States
| | - Kar Man Leung
- University of Southern California, Los Angeles, CA, United States
| | - Frank T Robb
- School of Medicine, University of Maryland, Baltimore, Baltimore, MD, United States
| | | | | | - Elizaveta A Bonch-Osmolovskaya
- Winogradsky Institute of Microbiology, FRC Biotechnology Russian Academy of Sciences, Moscow, Russia.,Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
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13
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Chen H, Simoska O, Lim K, Grattieri M, Yuan M, Dong F, Lee YS, Beaver K, Weliwatte S, Gaffney EM, Minteer SD. Fundamentals, Applications, and Future Directions of Bioelectrocatalysis. Chem Rev 2020; 120:12903-12993. [DOI: 10.1021/acs.chemrev.0c00472] [Citation(s) in RCA: 118] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Hui Chen
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Olja Simoska
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Koun Lim
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Matteo Grattieri
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Mengwei Yuan
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Fangyuan Dong
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Yoo Seok Lee
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Kevin Beaver
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Samali Weliwatte
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Erin M. Gaffney
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Shelley D. Minteer
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
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14
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Liu T, Luo X, Wu Y, Reinfelder JR, Yuan X, Li X, Chen D, Li F. Extracellular Electron Shuttling Mediated by Soluble c-Type Cytochromes Produced by Shewanella oneidensis MR-1. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:10577-10587. [PMID: 32692167 DOI: 10.1021/acs.est.9b06868] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
How metal-reducing bacteria transfer electrons during dissimilatory energy generation under electron acceptor-limited conditions is poorly understood. Here, we incubated the iron and manganese-reducing bacterium Shewanella oneidensis MR-1 without electron acceptors. Removal of soluble extracellular organic compounds (EOCs) dramatically retarded transfer of electrons to an experimental electron acceptor, Cr(VI), by MR-1. However, the return of either high MW (>3000 Da) or low MW (<3000 Da) soluble EOCs produced by MR-1 to washed cells restored Cr(VI) reduction though Cr(VI) reduction was fastest when both size fractions were added together. Spectral and electrochemical characterization of EOCs indicated the presence of flavins and c-type cytochromes (c-Cyts). A model of the kinetics of individual elementary reactions between cells, flavins, released c-Cyts, and Cr(VI), including the direct reduction of flavins, released c-Cyts, and Cr(VI) by cells and the indirect reduction of Cr(VI) by reduced forms of flavins and released c-Cyts, was developed. Model results suggest that released c-Cyts could act as electron mediators to accelerate electron transfer from cells to Cr(VI), and the relative contribution of this pathway was higher than that mediated by flavins. Hence, extracellular c-Cyts produced by MR-1 likely play a role in extracellular electron transfer under electron acceptor-limited conditions. These findings provide new insights into extracellular electron shuttling and the metabolic strategy of metal-reducing bacteria under electron acceptor-limited conditions.
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Affiliation(s)
- Tongxu Liu
- Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental Science & Technology, Guangzhou 510650, PR China
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou 510650, China
| | - Xiaobo Luo
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China
| | - Yundang Wu
- Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental Science & Technology, Guangzhou 510650, PR China
| | - John R Reinfelder
- Department of Environmental Sciences, Rutgers University, 14 College Farm Road, New Brunswick, New Jersey 08901, United States
| | - Xiu Yuan
- Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental Science & Technology, Guangzhou 510650, PR China
| | - Xiaomin Li
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Environmental Theoretical Chemistry, South China Normal University, Guangzhou 510006, China
| | - Dandan Chen
- Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental Science & Technology, Guangzhou 510650, PR China
| | - Fangbai Li
- Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental Science & Technology, Guangzhou 510650, PR China
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15
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Biofilm reactors for value-added products production: An in-depth review. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2020. [DOI: 10.1016/j.bcab.2020.101662] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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16
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Huang J, Zarzycki J, Gunner MR, Parson WW, Kern JF, Yano J, Ducat DC, Kramer DM. Mesoscopic to Macroscopic Electron Transfer by Hopping in a Crystal Network of Cytochromes. J Am Chem Soc 2020; 142:10459-10467. [DOI: 10.1021/jacs.0c02729] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Jingcheng Huang
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
| | - Jan Zarzycki
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
| | - M. R. Gunner
- Department of Physics, City College of New York, New York, New York 10031, United States
| | - William W. Parson
- Department of Biochemistry, University of Washington, Seattle, Washington 98195, United States
| | - Jan F. Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Junko Yano
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Daniel C. Ducat
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
| | - David M. Kramer
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
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17
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Bai Y, Mellage A, Cirpka OA, Sun T, Angenent LT, Haderlein SB, Kappler A. AQDS and Redox-Active NOM Enables Microbial Fe(III)-Mineral Reduction at cm-Scales. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:4131-4139. [PMID: 32108470 DOI: 10.1021/acs.est.9b07134] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Redox-active organic molecules such as anthraquinone-2,6-disulfonate (AQDS) and natural organic matter (NOM) can act as electron shuttles thus facilitating electron transfer from Fe(III)-reducing bacteria (FeRB) to terminal electron acceptors such as Fe(III) minerals. In this research, we examined the length scale over which this electron shuttling can occur. We present results from agar-solidified experimental incubations, containing either AQDS or NOM, where FeRB were physically separated from ferrihydrite or goethite by 2 cm. Iron speciation and concentration measurements coupled to a diffusion-reaction model highlighted clearly Fe(III) reduction in the presence of electron shuttles, independent of the type of FeRB. Based on our fitted model, the rate of ferrihydrite reduction increased from 0.07 to 0.19 μmol d-1 with a 10-fold increase in the AQDS concentration, highlighting a dependence of the reduction rate on the electron-shuttle concentration. To capture the kinetics of Fe(II) production, the effective AQDS diffusion coefficient had to be increased by a factor of 9.4. Thus, we postulate that the 2 cm electron transfer was enabled by a combination of AQDS molecular diffusion and an electron hopping contribution from reduced to oxidized AQDS molecules. Our results demonstrate that AQDS and NOM can drive microbial Fe(III) reduction across 2 cm distances and shed light on the electron transfer process in natural anoxic environments.
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Affiliation(s)
- Yuge Bai
- Geomicrobiology, Center for Applied Geosciences, University of Tübingen, Hölderlinstrasse 12, D-72074 Tübingen, Germany
| | - Adrian Mellage
- Hydrogeology, Center for Applied Geosciences, University of Tübingen, Hölderlinstrasse 12, D-72074 Tübingen, Germany
| | - Olaf A Cirpka
- Hydrogeology, Center for Applied Geosciences, University of Tübingen, Hölderlinstrasse 12, D-72074 Tübingen, Germany
| | - Tianran Sun
- Environmental Biotechnology, Center for Applied Geosciences, University of Tübingen, Hölderlinstrasse 12, D-72074 Tübingen, Germany
| | - Largus T Angenent
- Environmental Biotechnology, Center for Applied Geosciences, University of Tübingen, Hölderlinstrasse 12, D-72074 Tübingen, Germany
| | - Stefan B Haderlein
- Environmental Mineralogy and Chemistry, Center for Applied Geosciences, University of Tübingen, Hölderlinstrasse 12, D-72074 Tübingen, Germany
| | - Andreas Kappler
- Geomicrobiology, Center for Applied Geosciences, University of Tübingen, Hölderlinstrasse 12, D-72074 Tübingen, Germany
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18
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Grattieri M. Purple bacteria photo-bioelectrochemistry: enthralling challenges and opportunities. Photochem Photobiol Sci 2020; 19:424-435. [DOI: 10.1039/c9pp00470j] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Perspective of research directions exploring purple bacteria photo-bioelectrochemistry: from harvesting photoexcited electrons to bioelectrochemical systems development.
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19
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Heydorn RL, Engel C, Krull R, Dohnt K. Strategies for the Targeted Improvement of Anodic Electron Transfer in Microbial Fuel Cells. CHEMBIOENG REVIEWS 2019. [DOI: 10.1002/cben.201900023] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Raymond Leopold Heydorn
- Technische Universität BraunschweigInstitute of Biochemical Engineering, Braunschweig Integrated Centre of Systems Biology Rebenring 56 38106 Braunschweig Germany
| | - Christina Engel
- Technische Universität BraunschweigInstitute of Biochemical Engineering, Braunschweig Integrated Centre of Systems Biology Rebenring 56 38106 Braunschweig Germany
| | - Rainer Krull
- Technische Universität BraunschweigInstitute of Biochemical Engineering, Braunschweig Integrated Centre of Systems Biology Rebenring 56 38106 Braunschweig Germany
| | - Katrin Dohnt
- Technische Universität BraunschweigInstitute of Biochemical Engineering, Braunschweig Integrated Centre of Systems Biology Rebenring 56 38106 Braunschweig Germany
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20
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Xu H, Chang J, Wang H, Liu Y, Zhang X, Liang P, Huang X. Enhancing direct interspecies electron transfer in syntrophic-methanogenic associations with (semi)conductive iron oxides: Effects and mechanisms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 695:133876. [PMID: 31756846 DOI: 10.1016/j.scitotenv.2019.133876] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 08/09/2019] [Accepted: 08/09/2019] [Indexed: 06/10/2023]
Abstract
Anaerobic digestion is an effective biological treatment process that produces methane by degrading organic compounds in waste/wastewater. It is a complicated microbial process by metabolic interactions among different types of microorganisms. In this process, efficient interspecies electron transfer between secondary fermenting bacteria and methanogens is the critical process for fast and effective methanogenesis. In syntrophic metabolism, hydrogen or formate has been considered as the conventional electron carrier transferring electrons from secondary fermenting bacteria to hydrogenotrophic methanogens. Recently, direct interspecies electron transfer (DIET) without the involvement of dissolved redox mediators is arousing great concerns and has been regarded as a more efficient and thermodynamically favorable interspecies electron transfer pathway for methanogenesis. Interspecies electron exchange through DIET is accomplished via the membrane-bound cytochromes or conductive pili. Several kinds of exogenously-added conductive or semiconductive iron oxides have been discovered to greatly enhance anaerobic methanogenesis through promoting DIET. Different (semi)conductive iron oxides give a boost to DIET through different mechanisms based on the physicochemical properties of the iron oxides and the reciprocal interactions between iron oxides and functional microorganisms. In this review, the current understanding of interspecies electron transfer in syntrophic-methanogenic consortions is summarized, the effects and deep-rooted mechanisms of (semi)conductive iron oxides on methanogenesis and DIET are discussed, and possible future perspectives and development directions are suggested for DIET via (semi)conductive iron oxides in anaerobic digestion.
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Affiliation(s)
- Hui Xu
- State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment, Tsinghua University, Beijing 100084, China
| | - Jiali Chang
- State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment, Tsinghua University, Beijing 100084, China
| | - Han Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment, Tsinghua University, Beijing 100084, China
| | - Yancheng Liu
- State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment, Tsinghua University, Beijing 100084, China
| | - Xiaoyuan Zhang
- State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment, Tsinghua University, Beijing 100084, China
| | - Peng Liang
- State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment, Tsinghua University, Beijing 100084, China
| | - Xia Huang
- State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment, Tsinghua University, Beijing 100084, China.
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21
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Mayer F, Enzmann F, Lopez AM, Holtmann D. Performance of different methanogenic species for the microbial electrosynthesis of methane from carbon dioxide. BIORESOURCE TECHNOLOGY 2019; 289:121706. [PMID: 31279320 DOI: 10.1016/j.biortech.2019.121706] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 06/21/2019] [Accepted: 06/26/2019] [Indexed: 06/09/2023]
Abstract
Microbial electrosynthesis (MES) is a promising technology to convert CO2 and electricity into the biofuel methane using methanogens. Until now, most investigations on electro-methanogenesis are "proof-of-principle" studies. In this paper, different strains were quantitatively compared in regard to final methane concentration, yields based on CO2-conversion, productivities as well as Coulombic efficiencies in order to identify suitable organisms for MES. Methanococcus vannielii, Methanococcus maripaludis, Methanolacinia petrolearia, Methanobacterium congolense, and Methanoculleus submarinus were able to produce methane via MES at -700 mV vs. standard hydrogen electrode (SHE). Beside methane also biological H2 production was detected during MES, which might be due to the involvement of hydrogenases. A direct electron transfer pathway is most likely. Obviously, M. maripaludis is the most resource efficient methane producer in microbial electrosynthesis regarding the methane productivity (8.81 ± 0.51 mmol m-2 d-1) and the Coulombic efficiency (58.9 ± 0.8%).
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Affiliation(s)
- Florian Mayer
- DECHEMA-Forschungsinstitut, Industrielle Biotechnologie, Frankfurt am Main, Germany
| | - Franziska Enzmann
- DECHEMA-Forschungsinstitut, Industrielle Biotechnologie, Frankfurt am Main, Germany
| | | | - Dirk Holtmann
- DECHEMA-Forschungsinstitut, Industrielle Biotechnologie, Frankfurt am Main, Germany.
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22
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Heydorn RL, Engel C, Krull R, Dohnt K. Strategien zur gezielten Verbesserung des anodenseitigen Elektronentransfers in mikrobiellen Brennstoffzellen. CHEM-ING-TECH 2019. [DOI: 10.1002/cite.201800214] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Raymond Leopold Heydorn
- Technische Universität BraunschweigInstitut für Bioverfahrenstechnik, Braunschweiger Zentrum für Systembiologie Rebenring 56 38106 Braunschweig Deutschland
| | - Christina Engel
- Technische Universität BraunschweigInstitut für Bioverfahrenstechnik, Braunschweiger Zentrum für Systembiologie Rebenring 56 38106 Braunschweig Deutschland
| | - Rainer Krull
- Technische Universität BraunschweigInstitut für Bioverfahrenstechnik, Braunschweiger Zentrum für Systembiologie Rebenring 56 38106 Braunschweig Deutschland
| | - Katrin Dohnt
- Technische Universität BraunschweigInstitut für Bioverfahrenstechnik, Braunschweiger Zentrum für Systembiologie Rebenring 56 38106 Braunschweig Deutschland
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23
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Zhang X, Li X, Zhao X, Li Y. Factors affecting the efficiency of a bioelectrochemical system: a review. RSC Adv 2019; 9:19748-19761. [PMID: 35519388 PMCID: PMC9065546 DOI: 10.1039/c9ra03605a] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 06/11/2019] [Indexed: 11/21/2022] Open
Abstract
The great potential of bioelectrochemical systems (BESs) in pollution control combined with energy recovery has attracted increasing attention.
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Affiliation(s)
- Xiaolin Zhang
- Agro-Environmental Protection Institute
- Ministry of Agriculture and Rural Affairs/Key Laboratory of Original Agro-Environmental Pollution Prevention and Control
- MARA/Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety
- Tianjin 300191
- China
| | - Xiaojing Li
- Agro-Environmental Protection Institute
- Ministry of Agriculture and Rural Affairs/Key Laboratory of Original Agro-Environmental Pollution Prevention and Control
- MARA/Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety
- Tianjin 300191
- China
| | - Xiaodong Zhao
- Agro-Environmental Protection Institute
- Ministry of Agriculture and Rural Affairs/Key Laboratory of Original Agro-Environmental Pollution Prevention and Control
- MARA/Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety
- Tianjin 300191
- China
| | - Yongtao Li
- Agro-Environmental Protection Institute
- Ministry of Agriculture and Rural Affairs/Key Laboratory of Original Agro-Environmental Pollution Prevention and Control
- MARA/Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety
- Tianjin 300191
- China
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24
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Cheng P, Shan R, Yuan HR, Deng LF, Chen Y. Enhanced Rhodococcus pyridinivorans HR-1 anode performance by adding trehalose lipid in microbial fuel cell. BIORESOURCE TECHNOLOGY 2018; 267:774-777. [PMID: 30097358 DOI: 10.1016/j.biortech.2018.08.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 08/01/2018] [Accepted: 08/03/2018] [Indexed: 06/08/2023]
Abstract
In this study, a trehalose lipid was added to a Rhodococcus pyridinivorans-inoculated MFC to improve the power output by enhancing electron transfer. Upon trehalose lipid additions of different concentrate from 0 to 20 mg/L, the maximum power density increased from 54.7 mW/m2 to 324.4 mW/m2 (5.93 times) while the corresponding current density was 3.66 times increased from 0.35 A/m2 to 1.28 A/m2. Cyclic voltammetry analysis revealed that the addition of trehalose lipid increased the electron transfer performance, while electrochemical impedance spectroscopy results proved a decrease in internal resistance. It was demonstrated that adding bio-surfactant in MFC was a novel way to enhance power output performance.
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Affiliation(s)
- Peng Cheng
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China; Key Laboratory of Renewable Energy, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangdong Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China
| | - Rui Shan
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China; Key Laboratory of Renewable Energy, Chinese Academy of Sciences, Guangzhou 510640, China; Guangdong Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China
| | - Hao-Ran Yuan
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China; Key Laboratory of Renewable Energy, Chinese Academy of Sciences, Guangzhou 510640, China; Guangdong Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China.
| | - Li-Fang Deng
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China; Key Laboratory of Renewable Energy, Chinese Academy of Sciences, Guangzhou 510640, China; Guangdong Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China
| | - Yong Chen
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China; Key Laboratory of Renewable Energy, Chinese Academy of Sciences, Guangzhou 510640, China; Guangdong Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China
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Zhao W, Cui W, Xu S, Wang Y, Zhang K, Wang D, Cheong LZ, Besenbacher F, Shen C. Direct investigation of charge transfer in neurons by electrostatic force microscopy. Ultramicroscopy 2018; 196:24-32. [PMID: 30273806 DOI: 10.1016/j.ultramic.2018.09.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 09/05/2018] [Accepted: 09/20/2018] [Indexed: 10/28/2022]
Abstract
Charge transfer plays fundamental roles in information transmission in cells, especially in neurons. To date, direct observation of charge propagation in neurons at nanometer level has not been achieved yet. Herein, a combined charge injection and Electrostatic Force Microscopy (EFM) detection approach is applied to directly study charge propagation and distribution at nanometer resolution in spines and synapses of hippocampal neurons. Charge density, charge mobility and membrane potential in neural signal transmission process through the spines of axons and dendrites of hippocampal neurons were investigated quantitatively. Postsynaptic densities (PSD) in spines of axons and dendrites were revealed and studied. The methods and results from present work provide insights into physiological activities and processes related with electrical properties in nervous system and other biological samples.
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Affiliation(s)
- Weidong Zhao
- Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, 1219 Zhongguan Road, Ningbo, Zhejiang, China
| | - Wei Cui
- Ningbo Key Laboratory of Behavioral Neuroscience, Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, Zhejiang, China
| | - Shujun Xu
- Ningbo Key Laboratory of Behavioral Neuroscience, Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, Zhejiang, China
| | - Yuanyuan Wang
- Ningbo Key Laboratory of Behavioral Neuroscience, Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, Zhejiang, China
| | - Ke Zhang
- Ningbo Key Laboratory of Behavioral Neuroscience, Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, Zhejiang, China
| | - Deyu Wang
- Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, 1219 Zhongguan Road, Ningbo, Zhejiang, China
| | - Ling-Zhi Cheong
- School of Marine Science, Ningbo University, Ningbo, Zhejiang, China
| | | | - Cai Shen
- Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, 1219 Zhongguan Road, Ningbo, Zhejiang, China.
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Fu L, Song T, Zhang W, Zhang J, Lu Y. Stimulatory Effect of Magnetite Nanoparticles on a Highly Enriched Butyrate-Oxidizing Consortium. Front Microbiol 2018; 9:1480. [PMID: 30026737 PMCID: PMC6041394 DOI: 10.3389/fmicb.2018.01480] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 06/13/2018] [Indexed: 11/13/2022] Open
Abstract
Syntrophic oxidation of butyrate is catabolized by a few bacteria specialists in the presence of methanogens. In the present study, a highly enriched butyrate-oxidizing consortium was obtained from a wetland sediment in Tibetan Plateau. During continuous transfers of the enrichment, the addition of magnetite nanoparticles (nanoFe3O4) consistently enhanced butyrate oxidation and CH4 production. Molecular analysis revealed that all bacterial sequences from the consortium belonged to Syntrophomonas with the closest relative of Syntrophomonas wolfei and 96% of the archaeal sequences were related to Methanobacteria with the remaining sequences to Methanocella. Addition of graphite and carbon nanotubes for a replacement of nanoFe3O4 caused the similar stimulatory effect. Silica coating of nanoFe3O4 surface, however, completely eliminated the stimulatory effect. The control experiment with axenic cultivation of a Syntrophomonas strain and two methanogen strains showed no effect by nanoFe3O4. Together, the results in the present study support that syntrophic oxidation of butyrate is likely facilitated by direct interspecies electron transfer in the presence of conductive nanomaterials.
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Affiliation(s)
- Li Fu
- College of Urban and Environmental Sciences, Peking University, Beijing, China
- College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Tianze Song
- College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Wei Zhang
- College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Jie Zhang
- College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Yahai Lu
- College of Urban and Environmental Sciences, Peking University, Beijing, China
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Microbial nanowires - Electron transport and the role of synthetic analogues. Acta Biomater 2018; 69:1-30. [PMID: 29357319 DOI: 10.1016/j.actbio.2018.01.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 01/07/2018] [Accepted: 01/09/2018] [Indexed: 02/07/2023]
Abstract
Electron transfer is central to cellular life, from photosynthesis to respiration. In the case of anaerobic respiration, some microbes have extracellular appendages that can be utilised to transport electrons over great distances. Two model organisms heavily studied in this arena are Shewanella oneidensis and Geobacter sulfurreducens. There is some debate over how, in particular, the Geobacter sulfurreducens nanowires (formed from pilin nanofilaments) are capable of achieving the impressive feats of natural conductivity that they display. In this article, we outline the mechanisms of electron transfer through delocalised electron transport, quantum tunnelling, and hopping as they pertain to biomaterials. These are described along with existing examples of the different types of conductivity observed in natural systems such as DNA and proteins in order to provide context for understanding the complexities involved in studying the electron transport properties of these unique nanowires. We then introduce some synthetic analogues, made using peptides, which may assist in resolving this debate. Microbial nanowires and the synthetic analogues thereof are of particular interest, not just for biogeochemistry, but also for the exciting potential bioelectronic and clinical applications as covered in the final section of the review. STATEMENT OF SIGNIFICANCE Some microbes have extracellular appendages that transport electrons over vast distances in order to respire, such as the dissimilatory metal-reducing bacteria Geobacter sulfurreducens. There is significant debate over how G. sulfurreducens nanowires are capable of achieving the impressive feats of natural conductivity that they display: This mechanism is a fundamental scientific challenge, with important environmental and technological implications. Through outlining the techniques and outcomes of investigations into the mechanisms of such protein-based nanofibrils, we provide a platform for the general study of the electronic properties of biomaterials. The implications are broad-reaching, with fundamental investigations into electron transfer processes in natural and biomimetic materials underway. From these studies, applications in the medical, energy, and IT industries can be developed utilising bioelectronics.
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Meyer-Dombard DR, Casar CP, Simon AG, Cardace D, Schrenk MO, Arcilla CA. Biofilm formation and potential for iron cycling in serpentinization-influenced groundwater of the Zambales and Coast Range ophiolites. Extremophiles 2018; 22:407-431. [PMID: 29450709 DOI: 10.1007/s00792-018-1005-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Accepted: 02/05/2018] [Indexed: 02/01/2023]
Abstract
Terrestrial serpentinizing systems harbor microbial subsurface life. Passive or active microbially mediated iron transformations at alkaline conditions in deep biosphere serpentinizing ecosystems are understudied. We explore these processes in the Zambales (Philippines) and Coast Range (CA, USA) ophiolites, and associated surface ecosystems by probing the relevance of samples acquired at the surface to in situ, subsurface ecosystems, and the nature of microbe-mineral associations in the subsurface. In this pilot study, we use microcosm experiments and batch culturing directed at iron redox transformations to confirm thermodynamically based predictions that iron transformations may be important in subsurface serpentinizing ecosystems. Biofilms formed on rock cores from the Zambales ophiolite on surface and in-pit associations, confirming that organisms from serpentinizing systems can form biofilms in subsurface environments. Analysis by XPS and FTIR confirmed that enrichment culturing utilizing ferric iron growth substrates produced reduced, magnetic solids containing siderite, spinels, and FeO minerals. Microcosms and enrichment cultures supported organisms whose near relatives participate in iron redox transformations. Further, a potential 'principal' microbial community common to solid samples in serpentinizing systems was identified. These results indicate collectively that iron redox transformations should be more thoroughly and universally considered when assessing the function of terrestrial subsurface ecosystems driven by serpentinization.
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Affiliation(s)
- D'Arcy R Meyer-Dombard
- Department of Earth and Environmental Sciences, University of Illinois at Chicago, m/c 186, 845 W. Taylor St., Chicago, IL, 60515, USA.
| | - Caitlin P Casar
- Department of Earth and Environmental Sciences, University of Illinois at Chicago, m/c 186, 845 W. Taylor St., Chicago, IL, 60515, USA
| | - Alexander G Simon
- Department of Earth and Environmental Sciences, University of Illinois at Chicago, m/c 186, 845 W. Taylor St., Chicago, IL, 60515, USA
| | - Dawn Cardace
- Department of Geosciences, University of Rhode Island, Kingston, IL, USA
| | - Matthew O Schrenk
- Department of Earth and Environmental Sciences, Michigan State University, East Lansing, MI, USA
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
| | - Carlo A Arcilla
- National Institute of Geological Sciences, University of the Philippines, Diliman, Quezon City, Philippines
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John M, Trzcinski AP, Zhou Y, Ng WJ. Microbial stress mediated intercellular nanotubes in an anaerobic microbial consortium digesting cellulose. Sci Rep 2017; 7:18006. [PMID: 29269771 PMCID: PMC5740137 DOI: 10.1038/s41598-017-18198-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 12/05/2017] [Indexed: 01/15/2023] Open
Abstract
The anaerobic digestion process is a multi - step reaction dependent on concerted activities such as exchange of metabolites among physiologically different microbial communities. This study investigated the impact of iron oxide nanoparticles on the anaerobic sludge microbiota. It was shown there were three distinct microbial phases following addition of the nanoparticles: microbial stress and cell death of approximately one log order of magnitude, followed by microbial rewiring, and recovery. Furthermore, it was noted that cellular stress led to the establishment of intercellular nanotubes within the microbial biomass. Intercellular nanotube - mediated communication among genetically engineered microorganisms and ad hoc assembled co - cultures have been previously reported. This study presents evidence of intercellular nanotube formation within an environmental sample - i.e., anaerobic sludge microbiota subjected to stress. Our observations suggested a mode of microbial communication in the anaerobic digestion process not previously explored and which may have implications on bioreactor design and microbial functions.
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Affiliation(s)
- Martina John
- Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, #06-08, Singapore, 637141, Singapore.
- Division of Environmental and Water Resources, School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
| | - Antoine Prandota Trzcinski
- Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, #06-08, Singapore, 637141, Singapore
| | - Yan Zhou
- Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, #06-08, Singapore, 637141, Singapore
| | - Wun Jern Ng
- Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, #06-08, Singapore, 637141, Singapore.
- Division of Environmental and Water Resources, School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
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Seviour TW, Hinks J. Bucking the current trend in bioelectrochemical systems: a case for bioelectroanalytics. Crit Rev Biotechnol 2017; 38:634-646. [DOI: 10.1080/07388551.2017.1380599] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Thomas William Seviour
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore
| | - Jamie Hinks
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore
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32
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Affiliation(s)
- Derek R. Lovley
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts 01003
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33
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Electrically conductive pili from pilin genes of phylogenetically diverse microorganisms. ISME JOURNAL 2017; 12:48-58. [PMID: 28872631 DOI: 10.1038/ismej.2017.141] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 06/17/2017] [Accepted: 07/25/2017] [Indexed: 11/08/2022]
Abstract
The possibility that bacteria other than Geobacter species might contain genes for electrically conductive pili (e-pili) was investigated by heterologously expressing pilin genes of interest in Geobacter sulfurreducens. Strains of G. sulfurreducens producing high current densities, which are only possible with e-pili, were obtained with pilin genes from Flexistipes sinusarabici, Calditerrivibrio nitroreducens and Desulfurivibrio alkaliphilus. The conductance of pili from these strains was comparable to native G. sulfurreducens e-pili. The e-pili derived from C. nitroreducens, and D. alkaliphilus pilin genes are the first examples of relatively long (>100 amino acids) pilin monomers assembling into e-pili. The pilin gene from Candidatus Desulfofervidus auxilii did not yield e-pili, suggesting that the hypothesis that this sulfate reducer wires itself with e-pili to methane-oxidizing archaea to enable anaerobic methane oxidation should be reevaluated. A high density of aromatic amino acids and a lack of substantial aromatic-free gaps along the length of long pilins may be important characteristics leading to e-pili. This study demonstrates a simple method to screen pilin genes from difficult-to-culture microorganisms for their potential to yield e-pili; reveals new sources for biologically based electronic materials; and suggests that a wide phylogenetic diversity of microorganisms may use e-pili for extracellular electron exchange.
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Li C, Lesnik KL, Liu H. Stay connected: Electrical conductivity of microbial aggregates. Biotechnol Adv 2017; 35:669-680. [PMID: 28768145 DOI: 10.1016/j.biotechadv.2017.07.010] [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: 02/23/2017] [Revised: 07/25/2017] [Accepted: 07/27/2017] [Indexed: 01/01/2023]
Abstract
The discovery of direct extracellular electron transfer offers an alternative to the traditional understanding of diffusional electron exchange via small molecules. The establishment of electronic connections between electron donors and acceptors in microbial communities is critical to electron transfer via electrical currents. These connections are facilitated through conductivity associated with various microbial aggregates. However, examination of conductivity in microbial samples is still in its relative infancy and conceptual models in terms of conductive mechanisms are still being developed and debated. The present review summarizes the fundamental understanding of electrical conductivity in microbial aggregates (e.g. biofilms, granules, consortia, and multicellular filaments) highlighting recent findings and key discoveries. A greater understanding of electrical conductivity in microbial aggregates could facilitate the survey for additional microbial communities that rely on direct extracellular electron transfer for survival, inform rational design towards the aggregates-based production of bioenergy/bioproducts, and inspire the construction of new synthetic conductive polymers.
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Affiliation(s)
- Cheng Li
- Biological and Ecological Engineering, Oregon State University, Corvallis, OR 97333, USA
| | - Keaton Larson Lesnik
- Biological and Ecological Engineering, Oregon State University, Corvallis, OR 97333, USA
| | - Hong Liu
- Biological and Ecological Engineering, Oregon State University, Corvallis, OR 97333, USA.
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35
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Abstract
The growing ubiquity of electronic devices is increasingly consuming substantial energy and rare resources for materials fabrication, as well as creating expansive volumes of toxic waste. This is not sustainable. Electronic biological materials (e-biologics) that are produced with microbes, or designed with microbial components as the guide for synthesis, are a potential green solution. Some e-biologics can be fabricated from renewable feedstocks with relatively low energy inputs, often while avoiding the harsh chemicals used for synthesizing more traditional electronic materials. Several are completely free of toxic components, can be readily recycled, and offer unique features not found in traditional electronic materials in terms of size, performance, and opportunities for diverse functionalization. An appropriate investment in the concerted multidisciplinary collaborative research required to identify and characterize e-biologics and to engineer materials and devices based on e-biologics could be rewarded with a new "green age" of sustainable electronic materials and devices.
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Affiliation(s)
- Derek R Lovley
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA
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36
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Flemming HC, Wingender J, Szewzyk U, Steinberg P, Rice SA, Kjelleberg S. Biofilms: an emergent form of bacterial life. Nat Rev Microbiol 2017; 14:563-75. [PMID: 27510863 DOI: 10.1038/nrmicro.2016.94] [Citation(s) in RCA: 2762] [Impact Index Per Article: 394.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Bacterial biofilms are formed by communities that are embedded in a self-produced matrix of extracellular polymeric substances (EPS). Importantly, bacteria in biofilms exhibit a set of 'emergent properties' that differ substantially from free-living bacterial cells. In this Review, we consider the fundamental role of the biofilm matrix in establishing the emergent properties of biofilms, describing how the characteristic features of biofilms - such as social cooperation, resource capture and enhanced survival of exposure to antimicrobials - all rely on the structural and functional properties of the matrix. Finally, we highlight the value of an ecological perspective in the study of the emergent properties of biofilms, which enables an appreciation of the ecological success of biofilms as habitat formers and, more generally, as a bacterial lifestyle.
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Affiliation(s)
- Hans-Curt Flemming
- University of Duisburg-Essen, Faculty of Chemistry, Biofilm Centre, Universitätsstrasse 5, D-45141 Essen, Germany
| | - Jost Wingender
- University of Duisburg-Essen, Faculty of Chemistry, Biofilm Centre, Universitätsstrasse 5, D-45141 Essen, Germany
| | - Ulrich Szewzyk
- Technical University of Berlin, Department of Environmental Microbiology, Ernst-Reuter-Platz 1, D-10587 Berlin, Germany
| | - Peter Steinberg
- The School of Biological, Earth and Environmental Sciences and The Centre for Marine Bio-Innovation, University of New South Wales, Sydney, NSW 2052, Australia
| | - Scott A Rice
- The Singapore Centre for Environmental Life Sciences Engineering and the School of Biological Sciences, Nanyang Technological University, Singapore 637551
| | - Staffan Kjelleberg
- The Singapore Centre for Environmental Life Sciences Engineering and the School of Biological Sciences, Nanyang Technological University, Singapore 637551
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37
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Grattieri M, Shivel ND, Sifat I, Bestetti M, Minteer SD. Sustainable Hypersaline Microbial Fuel Cells: Inexpensive Recyclable Polymer Supports for Carbon Nanotube Conductive Paint Anodes. CHEMSUSCHEM 2017; 10:2053-2058. [PMID: 28244231 DOI: 10.1002/cssc.201700099] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 02/26/2017] [Indexed: 06/06/2023]
Abstract
Microbial fuel cells are an emerging technology for wastewater treatment, but to be commercially viable and sustainable, the electrode materials must be inexpensive, recyclable, and reliable. In this study, recyclable polymeric supports were explored for the development of anode electrodes to be applied in single-chamber microbial fuel cells operated in field under hypersaline conditions. The support was covered with a carbon nanotube (CNT) based conductive paint, and biofilms were able to colonize the electrodes. The single-chamber microbial fuel cells with Pt-free cathodes delivered a reproducible power output after 15 days of operation to achieve 12±1 mW m-2 at a current density of 69±7 mA m-2 . The decrease of the performance in long-term experiments was mostly related to inorganic precipitates on the cathode electrode and did not affect the performance of the anode, as shown by experiments in which the cathode was replaced and the fuel cell performance was regenerated. The results of these studies show the feasibility of polymeric supports coated with CNT-based paint for microbial fuel cell applications.
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Affiliation(s)
- Matteo Grattieri
- Departments of Chemistry and Material Science and Engineering, University of Utah, 315 S 1400 E Rm 2020, Salt Lake City, UT, 84112, USA
| | - Nelson D Shivel
- Departments of Chemistry and Material Science and Engineering, University of Utah, 315 S 1400 E Rm 2020, Salt Lake City, UT, 84112, USA
| | - Iram Sifat
- Departments of Chemistry and Material Science and Engineering, University of Utah, 315 S 1400 E Rm 2020, Salt Lake City, UT, 84112, USA
- United States-Pakistan Centre for Advanced Studies in Water, Mehran University of Engineering and Technology, Jamshoro, 76090, Sindh, Pakistan
| | - Massimiliano Bestetti
- Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, Piazza L. da Vinci 32, 20133, Milano, Italy
| | - Shelley D Minteer
- Departments of Chemistry and Material Science and Engineering, University of Utah, 315 S 1400 E Rm 2020, Salt Lake City, UT, 84112, USA
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Ferousi C, Lindhoud S, Baymann F, Kartal B, Jetten MSM, Reimann J. Iron assimilation and utilization in anaerobic ammonium oxidizing bacteria. Curr Opin Chem Biol 2017; 37:129-136. [DOI: 10.1016/j.cbpa.2017.03.009] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 03/08/2017] [Accepted: 03/14/2017] [Indexed: 02/07/2023]
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Zhang X, Philips J, Roume H, Guo K, Rabaey K, Prévoteau A. Rapid and Quantitative Assessment of Redox Conduction Across Electroactive Biofilms by using Double Potential Step Chronoamperometry. ChemElectroChem 2017. [DOI: 10.1002/celc.201600853] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Xu Zhang
- Center for Microbial Ecology and Technology (cmet); Ghent University; Coupure Links 653 9000 Ghent Belgium
| | - Jo Philips
- Center for Microbial Ecology and Technology (cmet); Ghent University; Coupure Links 653 9000 Ghent Belgium
| | - Hugo Roume
- Center for Microbial Ecology and Technology (cmet); Ghent University; Coupure Links 653 9000 Ghent Belgium
- MetaGenoPolis; INRA; Université Paris-Saclay Domaine de Vilvert; Bâtiment 325 78350 Jouy-en-Josas France
| | - Kun Guo
- Center for Microbial Ecology and Technology (cmet); Ghent University; Coupure Links 653 9000 Ghent Belgium
| | - Korneel Rabaey
- Center for Microbial Ecology and Technology (cmet); Ghent University; Coupure Links 653 9000 Ghent Belgium
| | - Antonin Prévoteau
- Center for Microbial Ecology and Technology (cmet); Ghent University; Coupure Links 653 9000 Ghent Belgium
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Expressing the Geobacter metallireducens PilA in Geobacter sulfurreducens Yields Pili with Exceptional Conductivity. mBio 2017; 8:mBio.02203-16. [PMID: 28096491 PMCID: PMC5241403 DOI: 10.1128/mbio.02203-16] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The electrically conductive pili (e-pili) of Geobacter sulfurreducens serve as a model for a novel strategy for long-range extracellular electron transfer. e-pili are also a new class of bioelectronic materials. However, the only other Geobacter pili previously studied, which were from G. uraniireducens, were poorly conductive. In order to obtain more information on the range of pili conductivities in Geobacter species, the pili of G. metallireducens were investigated. Heterologously expressing the PilA gene of G. metallireducens in G. sulfurreducens yielded a G. sulfurreducens strain, designated strain MP, that produced abundant pili. Strain MP exhibited phenotypes consistent with the presence of e-pili, such as high rates of Fe(III) oxide reduction and high current densities on graphite anodes. Individual pili prepared at physiologically relevant pH 7 had conductivities of 277 ± 18.9 S/cm (mean ± standard deviation), which is 5,000-fold higher than the conductivity of G. sulfurreducens pili at pH 7 and nearly 1 million-fold higher than the conductivity of G. uraniireducens pili at the same pH. A potential explanation for the higher conductivity of the G. metallireducens pili is their greater density of aromatic amino acids, which are known to be important components in electron transport along the length of the pilus. The G. metallireducens pili represent the most highly conductive pili found to date and suggest strategies for designing synthetic pili with even higher conductivities. IMPORTANCE e-pili are a remarkable electrically conductive material that can be sustainably produced without harsh chemical processes from renewable feedstocks and that contain no toxic components in the final product. Thus, e-pili offer an unprecedented potential for developing novel materials, electronic devices, and sensors for diverse applications with a new "green" technology. Increasing e-pili conductivity will even further expand their potential applications. A proven strategy is to design synthetic e-pili that contain tryptophan, an aromatic amino acid not found in previously studied e-pili. The studies reported here demonstrate that a productive alternative approach is to search more broadly in the microbial world. Surprisingly, even though G. metallireducens and G. sulfurreducens are closely related, the conductivities of their e-pili differ by more than 3 orders of magnitude. The ability to produce e-pili with high conductivity without generating a genetically modified product enhances the attractiveness of this novel electronic material.
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Shu C, Xiao K, Yan Q, Sun X. Comparative Analysis of Type IV Pilin in Desulfuromonadales. Front Microbiol 2016; 7:2080. [PMID: 28066394 PMCID: PMC5174107 DOI: 10.3389/fmicb.2016.02080] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 12/08/2016] [Indexed: 12/24/2022] Open
Abstract
During anaerobic respiration, the bacteria Geobacter sulfurreducens can transfer electrons to extracellular electron accepters through its pilus. G. sulfurreducens pili have been reported to have metallic-like conductivity that is similar to doped organic semiconductors. To study the characteristics and origin of conductive pilin proteins found in the pilus structure, their genetic, structural, and phylogenetic properties were analyzed. The genetic relationships, and conserved structures and sequences that were obtained were used to predict the evolution of the pilins. Homologous genes that encode conductive pilin were found using PilFind and Cluster. Sequence characteristics and protein tertiary structures were analyzed with MAFFT and QUARK, respectively. The origin of conductive pilins was explored by building a phylogenetic tree. Truncation is a characteristic of conductive pilin. The structures of truncated pilins and their accompanying proteins were found to be similar to the N-terminal and C-terminal ends of full-length pilins respectively. The emergence of the truncated pilins can probably be ascribed to the evolutionary pressure of their extracellular electron transporting function. Genes encoding truncated pilins and proteins similar to the C-terminal of full-length pilins, which contain a group of consecutive anti-parallel beta-sheets, are adjacent in bacterial genomes. According to the genetic, structure, and phylogenetic analyses performed in this study, we inferred that the truncated pilins and their accompanying proteins probably evolved from full-length pilins by gene fission through duplication, degeneration, and separation. These findings provide new insights about the molecular mechanisms involved in long-range electron transport along the conductive pili of Geobacter species.
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Affiliation(s)
| | | | | | - Xiao Sun
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast UniversityNanjing, China
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42
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Grattieri M, Hasan K, Minteer SD. Bioelectrochemical Systems as a Multipurpose Biosensing Tool: Present Perspective and Future Outlook. ChemElectroChem 2016. [DOI: 10.1002/celc.201600507] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Matteo Grattieri
- Departments of Chemistry and Materials Science & Engineering University of Utah 315 S 1400 E Salt Lake City UT 84112 USA
| | - Kamrul Hasan
- Departments of Chemistry and Materials Science & Engineering University of Utah 315 S 1400 E Salt Lake City UT 84112 USA
| | - Shelley D. Minteer
- Departments of Chemistry and Materials Science & Engineering University of Utah 315 S 1400 E Salt Lake City UT 84112 USA
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Lovley DR. Happy together: microbial communities that hook up to swap electrons. ISME JOURNAL 2016; 11:327-336. [PMID: 27801905 DOI: 10.1038/ismej.2016.136] [Citation(s) in RCA: 179] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 08/29/2016] [Accepted: 09/04/2016] [Indexed: 12/22/2022]
Abstract
The discovery of direct interspecies electron transfer (DIET) and cable bacteria has demonstrated that microbial cells can exchange electrons over long distances (μm-cm) through electrical connections. For example, in the presence of cable bacteria electrons are rapidly transported over centimeter distances, coupling the oxidation of reduced sulfur compounds in anoxic sediments to oxygen reduction in overlying surficial sediments. Bacteria and archaea wired for DIET are found in anaerobic methane-producing and methane-consuming communities. Electrical connections between gut microbes and host cells have also been proposed. Iterative environmental and defined culture studies on methanogenic communities revealed the importance of electrically conductive pili and c-type cytochromes in natural electrical grids, and demonstrated that conductive carbon materials and magnetite can substitute for these biological connectors to facilitate DIET. This understanding has led to strategies to enhance and stabilize anaerobic digestion. Key unknowns warranting further investigation include elucidation of the archaeal electrical connections facilitating DIET-based methane production and consumption; and the mechanisms for long-range electron transfer through cable bacteria. A better understanding of mechanisms for cell-to-cell electron transfer could facilitate the hunt for additional electrically connected microbial communities with omics approaches and could advance spin-off applications such as the development of sustainable bioelectronics materials and bioelectrochemical technologies.
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Affiliation(s)
- Derek R Lovley
- Department of Microbiology, Morrill IV N Science Center, University of Massachusetts, Amherst, MA, USA
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Holmes DE, Dang Y, Walker DJF, Lovley DR. The electrically conductive pili of Geobacter species are a recently evolved feature for extracellular electron transfer. Microb Genom 2016; 2:e000072. [PMID: 28348867 DOI: 10.1099/mgen.0.000072] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 05/31/2016] [Indexed: 12/14/2022] Open
Abstract
The electrically conductive pili (e-pili) of Geobactersulfurreducens have environmental and practical significance because they can facilitate electron transfer to insoluble Fe(III) oxides; to other microbial species; and through electrically conductive biofilms. E-pili conductivity has been attributed to the truncated PilA monomer, which permits tight packing of aromatic amino acids to form a conductive path along the length of e-pili. In order to better understand the evolution and distribution of e-pili in the microbial world, type IVa PilA proteins from various Gram-negative and Gram-positive bacteria were examined with a particular emphasis on Fe(III)-respiring bacteria. E-pilin genes are primarily restricted to a tight phylogenetic group in the order Desulfuromonadales. The downstream gene in all but one of the Desulfuromonadales that possess an e-pilin gene is a gene previously annotated as 'pilA-C' that has characteristics suggesting that it may encode an outer-membrane protein. Other genes associated with pilin function are clustered with e-pilin and 'pilA-C' genes in the Desulfuromonadales. In contrast, in the few bacteria outside the Desulfuromonadales that contain e-pilin genes, the other genes required for pilin function may have been acquired through horizontal gene transfer. Of the 95 known Fe(III)-reducing micro-organisms for which genomes are available, 80 % lack e-pilin genes, suggesting that e-pili are just one of several mechanisms involved in extracellular electron transport. These studies provide insight into where and when e-pili are likely to contribute to extracellular electron transport processes that are biogeochemically important and involved in bioenergy conversions.
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Affiliation(s)
- Dawn E Holmes
- 1Department of Microbiology, University of Massachusetts Amherst, Amherst, MA, USA.,2Department of Physical and Biological Sciences, Western New England University, Springfield, MA, USA
| | - Yan Dang
- 1Department of Microbiology, University of Massachusetts Amherst, Amherst, MA, USA
| | - David J F Walker
- 1Department of Microbiology, University of Massachusetts Amherst, Amherst, MA, USA
| | - Derek R Lovley
- 1Department of Microbiology, University of Massachusetts Amherst, Amherst, MA, USA
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Abstract
A sufficiently complex set of molecules, if subject to perturbation, will self-organize and show emergent behaviour. If such a system can take on information it will become subject to natural selection. This could explain how self-replicating molecules evolved into life and how intelligence arose. A pivotal step in this evolutionary process was of course the emergence of the eukaryote and the advent of the mitochondrion, which both enhanced energy production per cell and increased the ability to process, store and utilize information. Recent research suggest that from its inception life embraced quantum effects such as 'tunnelling' and 'coherence' while competition and stressful conditions provided a constant driver for natural selection. We believe that the biphasic adaptive response to stress described by hormesis-a process that captures information to enable adaptability, is central to this whole process. Critically, hormesis could improve mitochondrial quantum efficiency, improving the ATP/ROS ratio, whereas inflammation, which is tightly associated with the aging process, might do the opposite. This all suggests that to achieve optimal health and healthy aging, one has to sufficiently stress the system to ensure peak mitochondrial function, which itself could reflect selection of optimum efficiency at the quantum level.
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Affiliation(s)
- Alistair V W Nunn
- Research Centre for Optimal Health, Department of Life Sciences, University of Westminster, London W1W 6UW, U.K.
| | - Geoffrey W Guy
- GW Pharmaceuticals, Porton Down, Salisbury, Wiltshire SP4 0JQ, U.K
| | - Jimmy D Bell
- Research Centre for Optimal Health, Department of Life Sciences, University of Westminster, London W1W 6UW, U.K
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Xiao K, Malvankar NS, Shu C, Martz E, Lovley DR, Sun X. Low Energy Atomic Models Suggesting a Pilus Structure that could Account for Electrical Conductivity of Geobacter sulfurreducens Pili. Sci Rep 2016; 6:23385. [PMID: 27001169 PMCID: PMC4802205 DOI: 10.1038/srep23385] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Accepted: 03/03/2016] [Indexed: 12/18/2022] Open
Abstract
The metallic-like electrical conductivity of Geobacter sulfurreducens pili has been documented with multiple lines of experimental evidence, but there is only a rudimentary understanding of the structural features which contribute to this novel mode of biological electron transport. In order to determine if it was feasible for the pilin monomers of G. sulfurreducens to assemble into a conductive filament, theoretical energy-minimized models of Geobacter pili were constructed with a previously described approach, in which pilin monomers are assembled using randomized structural parameters and distance constraints. The lowest energy models from a specific group of predicted structures lacked a central channel, in contrast to previously existing pili models. In half of the no-channel models the three N-terminal aromatic residues of the pilin monomer are arranged in a potentially electrically conductive geometry, sufficiently close to account for the experimentally observed metallic like conductivity of the pili that has been attributed to overlapping pi-pi orbitals of aromatic amino acids. These atomic resolution models capable of explaining the observed conductive properties of Geobacter pili are a valuable tool to guide further investigation of the metallic-like conductivity of the pili, their role in biogeochemical cycling, and applications in bioenergy and bioelectronics.
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Affiliation(s)
- Ke Xiao
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China.,Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA
| | - Nikhil S Malvankar
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA
| | - Chuanjun Shu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| | - Eric Martz
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA
| | - Derek R Lovley
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA
| | - Xiao Sun
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
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Vassallo CN, Wall D. Tissue repair in myxobacteria: A cooperative strategy to heal cellular damage. Bioessays 2016; 38:306-15. [PMID: 26898360 DOI: 10.1002/bies.201500132] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Damage repair is a fundamental requirement of all life as organisms find themselves in challenging and fluctuating environments. In particular, damage to the barrier between an organism and its environment (e.g. skin, plasma membrane, bacterial cell envelope) is frequent because these organs/organelles directly interact with the external world. Here, we discuss the general strategies that bacteria use to cope with damage to their cell envelope and their repair limits. We then describe a novel damage-coping mechanism used by multicellular myxobacteria. We propose that cell-cell transfer of membrane material within a population serves as a wound-healing strategy and provide evidence for its utility. We suggest that--similar to how tissues in eukaryotes have evolved cooperative methods of damage repair--so too have some bacteria that live a multicellular lifestyle.
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Affiliation(s)
| | - Daniel Wall
- Department of Molecular Biology, University of Wyoming, Laramie, WY, USA
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Adhikari RY, Malvankar NS, Tuominen MT, Lovley DR. Conductivity of individual Geobacter pili. RSC Adv 2016. [DOI: 10.1039/c5ra28092c] [Citation(s) in RCA: 133] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Measurements of the conductivity of hydrated individual pili of Geobacter sulfurreducens that were not subjected to chemical fixation revealed conductivity along cytochrome-free regions comparable to conducting organic polymer nanowires of similar diameter.
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Affiliation(s)
| | - Nikhil S. Malvankar
- Department of Physics
- University of Massachusetts
- Amherst
- USA
- Department of Microbiology
| | | | - Derek R. Lovley
- Department of Microbiology
- University of Massachusetts
- Amherst
- USA
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Kalathil S, Pant D. Nanotechnology to rescue bacterial bidirectional extracellular electron transfer in bioelectrochemical systems. RSC Adv 2016. [DOI: 10.1039/c6ra04734c] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Advanced nanostructured electrode materials largely improve the bacterial bidirectional extracellular electron transfer in bioelectrochemical systems.
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Affiliation(s)
- Shafeer Kalathil
- Division of Biological and Environmental Science & Engineering
- King Abdullah University of Science and Technology
- Thuwal 23955-6900
- Saudi Arabia
| | - Deepak Pant
- Separation and Conversion Technology
- VITO – Flemish Institute for Technological Research
- 2400 Mol
- Belgium
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Dopson M, Ni G, Sleutels THJA. Possibilities for extremophilic microorganisms in microbial electrochemical systems. FEMS Microbiol Rev 2015; 40:164-81. [PMID: 26474966 PMCID: PMC4802824 DOI: 10.1093/femsre/fuv044] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2015] [Indexed: 11/12/2022] Open
Abstract
Microbial electrochemical systems exploit the metabolism of microorganisms to generate electrical energy or a useful product. In the past couple of decades, the application of microbial electrochemical systems has increased from the use of wastewaters to produce electricity to a versatile technology that can use numerous sources for the extraction of electrons on the one hand, while on the other hand these electrons can be used to serve an ever increasing number of functions. Extremophilic microorganisms grow in environments that are hostile to most forms of life and their utilization in microbial electrochemical systems has opened new possibilities to oxidize substrates in the anode and produce novel products in the cathode. For example, extremophiles can be used to oxidize sulfur compounds in acidic pH to remediate wastewaters, generate electrical energy from marine sediment microbial fuel cells at low temperatures, desalinate wastewaters and act as biosensors of low amounts of organic carbon. In this review, we will discuss the recent advances that have been made in using microbial catalysts under extreme conditions and show possible new routes that extremophilic microorganisms open for microbial electrochemical systems.
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Affiliation(s)
- Mark Dopson
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, SE-391 82 Kalmar, Sweden
| | - Gaofeng Ni
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, SE-391 82 Kalmar, Sweden
| | - Tom H J A Sleutels
- Wetsus, European Centre of Excellence for Sustainable Water Technology, 8911 MA Leeuwarden, The Netherlands
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