1
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You J, Ye L, Zhang S, Zhao J, Zhao Y, He Y, Chen J, Kennes C, Chen D. Electrode functional microorganisms in bioelectrochemical systems and its regulation: A review. Biotechnol Adv 2025; 79:108521. [PMID: 39814087 DOI: 10.1016/j.biotechadv.2025.108521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 12/03/2024] [Accepted: 01/12/2025] [Indexed: 01/18/2025]
Abstract
Bioelectrochemical systems (BES) as environmental remediation biotechnologies have boomed in the last two decades. Although BESs combined technologies with electro-chemistry, -biology, and -physics, microorganisms and biofilms remain at their core. In this review, various functional microorganisms in BESs for CO2 reduction, dehalogenation, nitrate, phosphate, and sulfate reduction, metal removal, and volatile organic compound oxidation are summarized and compared in detail. Moreover, interrelationship regulation approaches for functional microorganisms and methods for electroactive biofilm development, such as targeted electrode surface modification, chemical treatment, physical revealing, biological optimization, and genetic programming are pointed out. This review provides promising guidance and suggestions for the selection of microbial inoculants and provides an analysis of the role of individual microorganisms in mixed microbial communities and its metabolisms.
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Affiliation(s)
- Juping You
- Zhejiang Key Laboratory of Pullution control for Port-Petrochemical Industry, Zhejiang Ocean University, Zhoushan 316022, China; Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Zhejiang Shuren University, Hangzhou 312028, China
| | - Lei Ye
- Zhejiang Key Laboratory of Pullution control for Port-Petrochemical Industry, Zhejiang Ocean University, Zhoushan 316022, China
| | - Shihan Zhang
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jingkai Zhao
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Yan Zhao
- Zhejiang Key Laboratory of Pullution control for Port-Petrochemical Industry, Zhejiang Ocean University, Zhoushan 316022, China
| | - Yaxue He
- Zhejiang Key Laboratory of Pullution control for Port-Petrochemical Industry, Zhejiang Ocean University, Zhoushan 316022, China
| | - Jianmeng Chen
- School of Environment and Natural Resources, Zhejiang University of Science and Technology, Hangzhou 310018, China
| | - Christian Kennes
- Chemical Engineering Laboratory and Center for Advance Scientific Research (CICA), Faculty of Sciences, Universidade da Coruña, Spain
| | - Dongzhi Chen
- Zhejiang Key Laboratory of Pullution control for Port-Petrochemical Industry, Zhejiang Ocean University, Zhoushan 316022, China.
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2
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Galván FS, Alonso-Reyes DG, Albarracín VH. From genes to nanotubes: exploring the UV-resistome in the Andean extremophile Exiguobacterium sp. S17. Extremophiles 2025; 29:17. [PMID: 39964557 DOI: 10.1007/s00792-025-01383-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2024] [Accepted: 02/01/2025] [Indexed: 04/11/2025]
Abstract
Exiguobacterium sp. S17, a polyextremophile isolated from a High-Altitude Andean Lake, exhibits a multi-resistance profile against toxic arsenic concentrations, high UV radiation, and elevated salinity. Here, we characterize the mechanisms underlying the UV resistance of Exiguobacterium sp. S17 (UV-resistome) through comparative genomics within the Exiguobacterium genus and describe morphological and ultrastructural changes using Scanning (SEM) and Transmission (TEM) Electron Microscopy.UV-resistome in Exiguobacterium species ranges from 112 to 132 genes. While we anticipated Exiguobacterium sp. S17 to lead the non-HAAL UV-resistome, it ranked eleventh with 113 genes. This larger UV-resistome in Exiguobacterium spp. aligns with their known adaptation to extreme environments. With SEM/TEM analyses we observed the formation of nanotubes (NTs), a novel finding in Exiguobacterium spp., which increased with higher UV-B doses. These NTs, confirmed to be membranous structures through sensitivity studies and imaging, suggest a role in cellular communication and environmental sensing. Genomic evidence supports the presence of essential NT biogenesis genes in Exiguobacterium sp. S17, further elucidating its adaptive capabilities.Our study highlights the complex interplay of genetic and phenotypic adaptations enabling Exiguobacterium sp. S17 to thrive in extreme UV environments. The novel discovery of NTs under UV stress presents a new avenue for understanding bacterial survival strategies in harsh conditions.
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Affiliation(s)
- Fátima Silvina Galván
- Laboratorio de Microbiología Ultraestructural y Molecular, Centro Integral de Microscopía Electrónica (CIME), Facultad de Agronomía, Zootecnia y Veterinaria (FAZyV), UNT- CCT CONICET NOA SUR, CONICET, Tucumán, Argentina
| | - Daniel Gonzalo Alonso-Reyes
- Laboratorio de Microbiología Ultraestructural y Molecular, Centro Integral de Microscopía Electrónica (CIME), Facultad de Agronomía, Zootecnia y Veterinaria (FAZyV), UNT- CCT CONICET NOA SUR, CONICET, Tucumán, Argentina
| | - Virginia Helena Albarracín
- Laboratorio de Microbiología Ultraestructural y Molecular, Centro Integral de Microscopía Electrónica (CIME), Facultad de Agronomía, Zootecnia y Veterinaria (FAZyV), UNT- CCT CONICET NOA SUR, CONICET, Tucumán, Argentina.
- Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de Tucumán (UNT), Tucumán, Argentina.
- Centro Integral de Microscopía Electrónica (CIME, CONICET-UNT), Camino de Sirga S/N. FAZyV, Finca El Manantial, 4107, Yerba Buena, Tucumán, Argentina.
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3
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Perego C, König R, Cuomo M, Pianta E, Maye S, Di Maggio L, Moser M, Fischer F, Principi P. Shewanella oneidensis and Methanosarcina barkerii augmentation and conductive material effects on long-term anaerobic digestion performance. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2025; 18:10. [PMID: 39838449 PMCID: PMC11753057 DOI: 10.1186/s13068-025-02609-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2024] [Accepted: 01/08/2025] [Indexed: 01/23/2025]
Abstract
This study explores the use of conductive material in scaling up anaerobic digestion for enhanced biogas production. Focusing on Direct Interspecies Electron Transfer (DIET), the research employs a syntrophic DIET-able consortium formed by Shewanella oneidensis and Methanosarcina barkerii in 3.8-L experiments utilizing reticulated vitreous carbon (RVC) as conductive material. In short-term tests with acetate the syntrophic co-culture with RVC resulted in 86% higher maximum velocity of methane production, while in long term with real feed 13% increased rate was observed: the addition of 1.77 (S/m)*m2 RVC resulted in a faster methane production of 2.39 mL/gVS*h compared to 2.08 mL/gVS*h of the reference. The experimental conditions of syntrophic inoculum and RVC as conductive material gave a benefit in terms of process rate compared to the reference, considering the inoculum fate, Methanosarcina barkerii was among the dominant taxa at the end of the experiment, while Shewanella oneidensis was outcompeted. Among the methanogenesis production pathways, an increase of hydrogenotrophic methanogenesis has been observed in presence of conductive material. Further research is needed to understand the role of RVC in sulfur compounds production. Utilization of RVC to augment methane production yielded interesting results for real-scale application. As an added carrier, RVC remains unaltered and can be readily recuperated and reused multiple times.
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Affiliation(s)
- Camilla Perego
- Environmental Biotechnologies, Institute of Microbiology (IM) DACD Campus Mendrisio, University of Applied Sciences and Arts of Southern Switzerland SUPSI, Via Flora Ruchat-Roncati, 6850, Mendrisio, Switzerland
| | - Roger König
- Environmental Biotechnologies, Institute of Microbiology (IM) DACD Campus Mendrisio, University of Applied Sciences and Arts of Southern Switzerland SUPSI, Via Flora Ruchat-Roncati, 6850, Mendrisio, Switzerland
| | - Maurizio Cuomo
- Environmental Biotechnologies, Institute of Microbiology (IM) DACD Campus Mendrisio, University of Applied Sciences and Arts of Southern Switzerland SUPSI, Via Flora Ruchat-Roncati, 6850, Mendrisio, Switzerland
| | - Elisa Pianta
- Hygiene and the Environment, Institute of Microbiology (IM) DACD Campus Mendrisio, University of Applied Sciences and Arts of Southern Switzerland SUPSI, Via Flora Ruchat-Roncati, 6850, Mendrisio, Switzerland
| | - Sunny Maye
- Institute of Life Technologies, HES-SO Valais, University of Applied Sciences and Arts Western Switzerland Valais, Route du Rawyl 64, 1950, Sion, Switzerland
| | - Loredana Di Maggio
- Institute of Life Technologies, HES-SO Valais, University of Applied Sciences and Arts Western Switzerland Valais, Route du Rawyl 64, 1950, Sion, Switzerland
| | - Michel Moser
- Institute of Microbiology (IM) DACD Campus Mendrisio, University of Applied Sciences and Arts of Southern Switzerland SUPSI, Via Flora Ruchat-Roncati, 6850, Mendrisio, Switzerland
| | - Fabian Fischer
- Institute of Life Technologies, HES-SO Valais, University of Applied Sciences and Arts Western Switzerland Valais, Route du Rawyl 64, 1950, Sion, Switzerland
| | - Pamela Principi
- Environmental Biotechnologies, Institute of Microbiology (IM) DACD Campus Mendrisio, University of Applied Sciences and Arts of Southern Switzerland SUPSI, Via Flora Ruchat-Roncati, 6850, Mendrisio, Switzerland.
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4
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Li FH, Liang ZH, Sun H, Tang Q, Yu HQ. Engineering Programmable Electroactive Living Materials for Highly Efficient Uranium Capture and Accumulation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:23053-23063. [PMID: 39688929 DOI: 10.1021/acs.est.4c07276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2024]
Abstract
Uranium is the primary fuel for nuclear energy, critical for sustainable, carbon-neutral energy transitions. However, limited terrestrial resources and environmental risks from uranium contamination require innovative immobilization and recovery solutions. In this work, we present a novel uranium recovery method using programmable electroactive living materials (ELMs). Utilizing Shewanella oneidensis, this approach leverages the intrinsic extracellular electron transfer capability of exoelectrogenic species, combining their adaptability and programmability with the robustness of engineered multicellular systems. These exoelectrogenic cells were endowed to selectively capture and enhance U(VI) reduction by expressing uranyl-binding proteins, coupled with a reconfigured transmembrane Mtr electron nanoconduit. By incorporating biofilm-promoting circuits, we improved cell-to-cell interactions and biofilm formation, enabling the stable assembly of ELMs with robust structural integrity. The ELMs demonstrated superior electrogenic activity, achieving a 3.30-fold increase in current density and a 3.15-fold increase in voltage output compared to controls in microbial electrochemical and fuel cells. When applied for uranium recovery, the ELMs exhibited robust U(VI) capture, reduction, and accumulation capabilities, with a maximum capacity of 808.42 μmol/g. This work not only provides a versatile and environmentally friendly solution for uranium recovery, but also highlights the potential of ELMs in sustainable environmental and energy technologies.
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Affiliation(s)
- Feng-He Li
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
- School of Life Sciences, University of Science and Technology of China, Hefei 230026, China
- School of Pharmacy, The Second Affiliated Hospital of Anhui Medical University, Anhui Medical University, Hefei 230032, China
| | - Zi-Han Liang
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Hong Sun
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Qiang Tang
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Han-Qing Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
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Nash BW, Fernandes TM, Burton JAJ, Morgado L, van Wonderen JH, Svistunenko DA, Edwards MJ, Salgueiro CA, Butt JN, Clarke TA. Tethered heme domains in a triheme cytochrome allow for increased electron transport distances. Protein Sci 2024; 33:e5200. [PMID: 39470321 PMCID: PMC11520253 DOI: 10.1002/pro.5200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2024] [Revised: 10/08/2024] [Accepted: 10/12/2024] [Indexed: 10/30/2024]
Abstract
Decades of research describe myriad redox enzymes that contain cofactors arranged in tightly packed chains facilitating rapid and controlled intra-protein electron transfer. Many such enzymes participate in extracellular electron transfer (EET), a process which allows microorganisms to conserve energy in anoxic environments by exploiting mineral oxides and other extracellular substrates as terminal electron acceptors. In this work, we describe the properties of the triheme cytochrome PgcA from Geobacter sulfurreducens. PgcA has been shown to play an important role in EET but is unusual in containing three CXXCH heme binding motifs that are separated by repeated (PT)x motifs, suggested to enhance binding to mineral surfaces. Using a combination of structural, electrochemical, and biophysical techniques, we experimentally demonstrate that PgcA adopts numerous conformations stretching as far as 180 Å between the ends of domains I and III, without a tightly packed cofactor chain. Furthermore, we demonstrate a distinct role for its domain III as a mineral reductase that is recharged by domains I and II. These findings show PgcA to be the first of a new class of electron transfer proteins, with redox centers separated by some nanometers but tethered together by flexible linkers, facilitating electron transfer through a tethered diffusion mechanism rather than a fixed, closely packed electron transfer chain.
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Affiliation(s)
- Benjamin W. Nash
- Centre for Molecular and Structural BiochemistrySchool of Biological Sciences and School of Chemistry, University of East AngliaNorwichUK
| | - Tomás M. Fernandes
- Associate Laboratory i4HB – Institute for Health and BioeconomyNOVA School of Science and Technology, Universidade NOVA de LisboaCaparicaPortugal
- UCIBIO – Applied Molecular Biosciences Unit, Chemistry DepartmentNOVA School of Science and Technology, Universidade NOVA de LisboaCaparicaPortugal
| | - Joshua A. J. Burton
- Centre for Molecular and Structural BiochemistrySchool of Biological Sciences and School of Chemistry, University of East AngliaNorwichUK
| | - Leonor Morgado
- Associate Laboratory i4HB – Institute for Health and BioeconomyNOVA School of Science and Technology, Universidade NOVA de LisboaCaparicaPortugal
- UCIBIO – Applied Molecular Biosciences Unit, Chemistry DepartmentNOVA School of Science and Technology, Universidade NOVA de LisboaCaparicaPortugal
| | - Jessica H. van Wonderen
- Centre for Molecular and Structural BiochemistrySchool of Biological Sciences and School of Chemistry, University of East AngliaNorwichUK
| | | | | | - Carlos A. Salgueiro
- Associate Laboratory i4HB – Institute for Health and BioeconomyNOVA School of Science and Technology, Universidade NOVA de LisboaCaparicaPortugal
- UCIBIO – Applied Molecular Biosciences Unit, Chemistry DepartmentNOVA School of Science and Technology, Universidade NOVA de LisboaCaparicaPortugal
| | - Julea N. Butt
- Centre for Molecular and Structural BiochemistrySchool of Biological Sciences and School of Chemistry, University of East AngliaNorwichUK
| | - Thomas A. Clarke
- Centre for Molecular and Structural BiochemistrySchool of Biological Sciences and School of Chemistry, University of East AngliaNorwichUK
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6
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Klein EM, Heintz H, Wurst R, Schuldt S, Hähl H, Jacobs K, Gescher J. Comparative analysis of the influence of BpfA and BpfG on biofilm development and current density in Shewanella oneidensis under oxic, fumarate- and anode-respiring conditions. Sci Rep 2024; 14:23174. [PMID: 39369013 PMCID: PMC11455927 DOI: 10.1038/s41598-024-73474-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2024] [Accepted: 09/17/2024] [Indexed: 10/07/2024] Open
Abstract
Biofilm formation by Shewanella oneidensis has been extensively studied under oxic conditions; however, relatively little is known about biofilm formation under anoxic conditions and how biofilm architecture and composition can positively influence current generation in bioelectrochemical systems. In this study, we utilized a recently developed microfluidic biofilm analysis setup with automated 3D imaging to investigate the effects of extracellular electron acceptors and synthetic modifications to the extracellular polymeric matrix on biofilm formation. Our results with the wild type strain demonstrate robust biofilm formation even under anoxic conditions when fumarate is used as the electron acceptor. However, this pattern shifts when a graphite electrode is employed as the electron acceptor, resulting in biofilm formation falling below the detection limit of the optical coherence tomography imaging system. To manipulate biofilm formation, we aimed to express BpfG with a single amino acid substitution in the catalytic center (C116S) and to overexpress bpfA. Our analyses indicate that, under oxic conditions, overarching mechanisms predominantly influence biofilm development, rather than the specific mutations we investigated. Under anoxic conditions, the bpfG mutation led to a quantitative increase in biofilm formation, but both strains exhibited significant qualitative changes in biofilm architecture compared to the controls. When an anode was used as the sole electron acceptor, both the bpfA and bpfG mutations positively impacted mean current density, yielding a 1.8-fold increase for each mutation.
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Affiliation(s)
- Edina Marlen Klein
- Institute of Technical Microbiology, University of Technology Hamburg, 21073, Hamburg, Germany
| | - Hannah Heintz
- Experimental Physics, Center for Biophysics, Saarland University, 66123, Saarbrücken, Germany
| | - René Wurst
- Institute of Technical Microbiology, University of Technology Hamburg, 21073, Hamburg, Germany
| | - Simon Schuldt
- Institute of Technical Microbiology, University of Technology Hamburg, 21073, Hamburg, Germany
| | - Hendrik Hähl
- Experimental Physics, Center for Biophysics, Saarland University, 66123, Saarbrücken, Germany
| | - Karin Jacobs
- Experimental Physics, Center for Biophysics, Saarland University, 66123, Saarbrücken, Germany
- Max Planck School Matter to Life, 69120, Heidelberg, Germany
| | - Johannes Gescher
- Institute of Technical Microbiology, University of Technology Hamburg, 21073, Hamburg, Germany.
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Morriss CE, Cheung CK, Nunn E, Parmeggiani F, Powell NA, Kimber RL, Haigh SJ, Lloyd JR. Biosynthesis Parameters Control the Physicochemical and Catalytic Properties of Microbially Supported Pd Nanoparticles. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2311016. [PMID: 38461530 DOI: 10.1002/smll.202311016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 02/12/2024] [Indexed: 03/12/2024]
Abstract
The biosynthesis of Pd nanoparticles supported on microorganisms (bio-Pd) is achieved via the enzymatic reduction of Pd(II) to Pd(0) under ambient conditions using inexpensive buffers and electron donors, like organic acids or hydrogen. Sustainable bio-Pd catalysts are effective for C-C coupling and hydrogenation reactions, but their industrial application is limited by challenges in controlling nanoparticle properties. Here, using the metal-reducing bacterium Geobacter sulfurreducens, it is demonstrated that synthesizing bio-Pd under different Pd loadings and utilizing different electron donors (acetate, formate, hydrogen, no e- donor) influences key properties such as nanoparticle size, Pd(II):Pd(0) ratio, and cellular location. Controlling nanoparticle size and location controls the activity of bio-Pd for the reduction of 4-nitrophenol, whereas high Pd loading on cells synthesizes bio-Pd with high activity, comparable to commercial Pd/C, for Suzuki-Miyaura coupling reactions. Additionally, the study demonstrates the novel synthesis of microbially-supported ≈2 nm PdO nanoparticles due to the hydrolysis of biosorbed Pd(II) in bicarbonate buffer. Bio-PdO nanoparticles show superior activity in 4-nitrophenol reduction compared to commercial Pd/C catalysts. Overall, controlling biosynthesis parameters, such as electron donor, metal loading, and solution chemistry, enables tailoring of bio-Pd physicochemical and catalytic properties.
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Affiliation(s)
- Christopher Egan Morriss
- Department of Earth and Environmental Sciences, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
- Department of Materials, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Casey K Cheung
- Department of Materials, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Elliot Nunn
- Department of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Fabio Parmeggiani
- Dipartimento di Chimica, Materiali ed Ingegneria Chimica "Giulio Natta", Politecnico di Milano, Piazza Leonardo da Vinci, Milan, 20133, Italy
| | | | - Richard L Kimber
- Department of Earth and Environmental Sciences, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Sarah J Haigh
- Department of Materials, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Jonathan R Lloyd
- Department of Earth and Environmental Sciences, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
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8
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Ao TJ, Liu CG, Sun ZY, Zhao XQ, Tang YQ, Bai FW. Anaerobic digestion integrated with microbial electrolysis cell to enhance biogas production and upgrading in situ. Biotechnol Adv 2024; 73:108372. [PMID: 38714276 DOI: 10.1016/j.biotechadv.2024.108372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 04/22/2024] [Accepted: 05/01/2024] [Indexed: 05/09/2024]
Abstract
Anaerobic digestion (AD) is an effective and applicable technology for treating organic wastes to recover bioenergy, but it is limited by various drawbacks, such as long start-up time for establishing a stable process, the toxicity of accumulated volatile fatty acids and ammonia nitrogen to methanogens resulting in extremely low biogas productivities, and a large amount of impurities in biogas for upgrading thereafter with high cost. Microbial electrolysis cell (MEC) is a device developed for electrosynthesis from organic wastes by electroactive microorganisms, but MEC alone is not practical for production at large scales. When AD is integrated with MEC, not only can biogas production be enhanced substantially, but also upgrading of the biogas product performed in situ. In this critical review, the state-of-the-art progress in developing AD-MEC systems is commented, and fundamentals underlying methanogenesis and bioelectrochemical reactions, technological innovations with electrode materials and configurations, designs and applications of AD-MEC systems, and strategies for their enhancement, such as driving the MEC device by electricity that is generated by burning the biogas to improve their energy efficiencies, are specifically addressed. Moreover, perspectives and challenges for the scale up of AD-MEC systems are highlighted for in-depth studies in the future to further improve their performance.
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Affiliation(s)
- Tian-Jie Ao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Chen-Guang Liu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
| | - Zhao-Yong Sun
- College of Architecture & Environment, Sichuan University, Chengdu 610000, China
| | - Xin-Qing Zhao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
| | - Yue-Qin Tang
- College of Architecture & Environment, Sichuan University, Chengdu 610000, China
| | - Feng-Wu Bai
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
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9
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Lin T, Ding W, Zhang D, You Z, Yang Y, Li F, Xu D, Lovley DR, Song H. Expression of filaments of the Geobacter extracellular cytochrome OmcS in Shewanella oneidensis. Biotechnol Bioeng 2024; 121:2002-2012. [PMID: 38555482 DOI: 10.1002/bit.28702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 03/01/2024] [Accepted: 03/11/2024] [Indexed: 04/02/2024]
Abstract
The physiological role of Geobacter sulfurreducens extracellular cytochrome filaments is a matter of debate and the development of proposed electronic device applications of cytochrome filaments awaits methods for large-scale cytochrome nanowire production. Functional studies in G. sulfurreducens are stymied by the broad diversity of redox-active proteins on the outer cell surface and the redundancy and plasticity of extracellular electron transport routes. G. sulfurreducens is a poor chassis for producing cytochrome nanowires for electronics because of its slow, low-yield, anaerobic growth. Here we report that filaments of the G. sulfurreducens cytochrome OmcS can be heterologously expressed in Shewanella oneidensis. Multiple lines of evidence demonstrated that a strain of S. oneidensis, expressing the G. sulfurreducens OmcS gene on a plasmid, localized OmcS on the outer cell surface. Atomic force microscopy revealed filaments with the unique morphology of OmcS filaments emanating from cells. Electron transfer to OmcS appeared to require a functional outer-membrane porin-cytochrome conduit. The results suggest that S. oneidensis, which grows rapidly to high culture densities under aerobic conditions, may be suitable for the development of a chassis for producing cytochrome nanowires for electronics applications and may also be a good model microbe for elucidating cytochrome filament function in anaerobic extracellular electron transfer.
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Affiliation(s)
- Tong Lin
- Frontiers Science Centre for Synthetic Biology (Ministry of Education), and Key Laboratory of Systems Bioengineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
- College of Life Science, Langfang Normal University, Langfang, Hebei, China
| | - Wenqi Ding
- Frontiers Science Centre for Synthetic Biology (Ministry of Education), and Key Laboratory of Systems Bioengineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Danni Zhang
- Shenyang National Laboratory for Materials Science, Northeastern University, Shenyang, China
- Electrobiomaterials Institute, Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang, China
| | - Zixuan You
- Frontiers Science Centre for Synthetic Biology (Ministry of Education), and Key Laboratory of Systems Bioengineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Yun Yang
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Engineering Medicine, Beihang University, Beijing, China
| | - Feng Li
- Frontiers Science Centre for Synthetic Biology (Ministry of Education), and Key Laboratory of Systems Bioengineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Dake Xu
- Shenyang National Laboratory for Materials Science, Northeastern University, Shenyang, China
- Electrobiomaterials Institute, Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang, China
| | - Derek R Lovley
- Shenyang National Laboratory for Materials Science, Northeastern University, Shenyang, China
- Electrobiomaterials Institute, Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang, China
| | - Hao Song
- Frontiers Science Centre for Synthetic Biology (Ministry of Education), and Key Laboratory of Systems Bioengineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
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10
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Portela PC, Shipps CC, Shen C, Srikanth V, Salgueiro CA, Malvankar NS. Widespread extracellular electron transfer pathways for charging microbial cytochrome OmcS nanowires via periplasmic cytochromes PpcABCDE. Nat Commun 2024; 15:2434. [PMID: 38509081 PMCID: PMC10954620 DOI: 10.1038/s41467-024-46192-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 02/19/2024] [Indexed: 03/22/2024] Open
Abstract
Extracellular electron transfer (EET) via microbial nanowires drives globally-important environmental processes and biotechnological applications for bioenergy, bioremediation, and bioelectronics. Due to highly-redundant and complex EET pathways, it is unclear how microbes wire electrons rapidly (>106 s-1) from the inner-membrane through outer-surface nanowires directly to an external environment despite a crowded periplasm and slow (<105 s-1) electron diffusion among periplasmic cytochromes. Here, we show that Geobacter sulfurreducens periplasmic cytochromes PpcABCDE inject electrons directly into OmcS nanowires by binding transiently with differing efficiencies, with the least-abundant cytochrome (PpcC) showing the highest efficiency. Remarkably, this defined nanowire-charging pathway is evolutionarily conserved in phylogenetically-diverse bacteria capable of EET. OmcS heme reduction potentials are within 200 mV of each other, with a midpoint 82 mV-higher than reported previously. This could explain efficient EET over micrometres at ultrafast (<200 fs) rates with negligible energy loss. Engineering this minimal nanowire-charging pathway may yield microbial chassis with improved performance.
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Affiliation(s)
- Pilar C Portela
- Microbial Sciences Institute, Yale University, West Haven, CT, USA
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal
- UCIBIO - Applied Molecular Biosciences Unit, Department of Chemistry, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Catharine C Shipps
- Microbial Sciences Institute, Yale University, West Haven, CT, USA
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Cong Shen
- Microbial Sciences Institute, Yale University, West Haven, CT, USA
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Vishok Srikanth
- Microbial Sciences Institute, Yale University, West Haven, CT, USA
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Carlos A Salgueiro
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal.
- UCIBIO - Applied Molecular Biosciences Unit, Department of Chemistry, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal.
| | - Nikhil S Malvankar
- Microbial Sciences Institute, Yale University, West Haven, CT, USA.
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA.
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11
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van Wonderen JH, Crack JC, Edwards MJ, Clarke TA, Saalbach G, Martins C, Butt JN. Liquid-chromatography mass spectrometry describes post-translational modification of Shewanella outer membrane proteins. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184221. [PMID: 37673350 DOI: 10.1016/j.bbamem.2023.184221] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 08/09/2023] [Accepted: 08/30/2023] [Indexed: 09/08/2023]
Abstract
Electrogenic bacteria deliver excess respiratory electrons to externally located metal oxide particles and electrodes. The biochemical basis for this process is arguably best understood for species of Shewanella where the integral membrane complex termed MtrCAB is key to electron transfer across the bacterial outer membranes. A crystal structure was recently resolved for MtrCAB from S. baltica OS185. However, X-ray diffraction did not resolve the N-terminal residues so that the lipidation status of proteins in the mature complex was poorly described. Here we report liquid chromatography mass spectrometry revealing the intact mass values for all three proteins in the MtrCAB complexes purified from Shewanella oneidensis MR-1 and S. baltica OS185. The masses of MtrA and MtrB are consistent with both proteins being processed by Signal Peptidase I and covalent attachment of ten c-type hemes to MtrA. The mass of MtrC is most reasonably interpreted as arising from protein processed by Signal Peptidase II to produce a diacylated lipoprotein containing ten c-type hemes. Our two-step protocol for liquid-chromatography mass spectrometry used a reverse phase column to achieve on-column detergent removal prior to gradient protein resolution and elution. We envisage the method will be capable of simultaneously resolving the intact mass values for multiple proteins in other membrane protein complexes.
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Affiliation(s)
- Jessica H van Wonderen
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
| | - Jason C Crack
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Marcus J Edwards
- School of Biological Sciences, University of East Anglia, , Norwich Research Park, Norwich NR4 7TJ, UK; School of Life Sciences, University of Essex, Colchester CO4 3SQ, UK
| | - Thomas A Clarke
- School of Biological Sciences, University of East Anglia, , Norwich Research Park, Norwich NR4 7TJ, UK
| | - Gerhard Saalbach
- Proteomics Facility, The John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Carlo Martins
- Proteomics Facility, The John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Julea N Butt
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK; School of Biological Sciences, University of East Anglia, , Norwich Research Park, Norwich NR4 7TJ, UK.
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12
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Pimenta AI, Paquete CM, Morgado L, Edwards MJ, Clarke TA, Salgueiro CA, Pereira IAC, Duarte AG. Characterization of the inner membrane cytochrome ImcH from Geobacter reveals its importance for extracellular electron transfer and energy conservation. Protein Sci 2023; 32:e4796. [PMID: 37779214 PMCID: PMC10601379 DOI: 10.1002/pro.4796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 08/30/2023] [Accepted: 09/16/2023] [Indexed: 10/03/2023]
Abstract
Electroactive bacteria combine the oxidation of carbon substrates with an extracellular electron transfer (EET) process that discharges electrons to an electron acceptor outside the cell. This process involves electron transfer through consecutive redox proteins that efficiently connect the inner membrane to the cell exterior. In this study, we isolated and characterized the quinone-interacting membrane cytochrome c ImcH from Geobacter sulfurreducens, which is involved in the EET process to high redox potential acceptors. Spectroscopic and electrochemical studies show that ImcH hemes have low midpoint redox potentials, ranging from -150 to -358 mV, and connect the oxidation of the quinol-pool to EET, transferring electrons to the highly abundant periplasmic cytochrome PpcA with higher affinity than to its homologues. Despite the larger number of hemes and transmembrane helices, the ImcH structural model has similarities with the NapC/NirT/NrfH superfamily, namely the presence of a quinone-binding site on the P-side of the membrane. In addition, the first heme, likely involved on the quinol oxidation, has apparently an unusual His/Gln coordination. Our work suggests that ImcH is electroneutral and transfers electrons and protons to the same side of the membrane, contributing to the maintenance of a proton motive force and playing a central role in recycling the menaquinone pool.
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Affiliation(s)
- Andreia I. Pimenta
- Instituto de Tecnologia Química e Biológica António XavierUniversidade Nova de LisboaOeirasPortugal
| | - Catarina M. Paquete
- Instituto de Tecnologia Química e Biológica António XavierUniversidade Nova de LisboaOeirasPortugal
| | - Leonor Morgado
- Associate Laboratory i4HB—Institute for Health and Bioeconomy, NOVA School of Science and TechnologyUniversidade NOVA de LisboaCaparicaPortugal
- UCIBIO—Applied Molecular Biosciences Unit, Department of Chemistry, NOVA School of Science and TechnologyUniversidade NOVA de LisboaCaparicaPortugal
| | | | - Thomas A. Clarke
- Centre for Molecular and Structural Biochemistry, School of Biological SciencesUniversity of East AngliaNorwichUK
| | - Carlos A. Salgueiro
- Associate Laboratory i4HB—Institute for Health and Bioeconomy, NOVA School of Science and TechnologyUniversidade NOVA de LisboaCaparicaPortugal
- UCIBIO—Applied Molecular Biosciences Unit, Department of Chemistry, NOVA School of Science and TechnologyUniversidade NOVA de LisboaCaparicaPortugal
| | - Inês A. C. Pereira
- Instituto de Tecnologia Química e Biológica António XavierUniversidade Nova de LisboaOeirasPortugal
| | - Américo G. Duarte
- Instituto de Tecnologia Química e Biológica António XavierUniversidade Nova de LisboaOeirasPortugal
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13
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Fernandes TM, Silva MA, Morgado L, Salgueiro CA. Hemes on a string: insights on the functional mechanisms of PgcA from Geobacter sulfurreducens. J Biol Chem 2023; 299:105167. [PMID: 37595873 PMCID: PMC10570954 DOI: 10.1016/j.jbc.2023.105167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 08/05/2023] [Accepted: 08/10/2023] [Indexed: 08/20/2023] Open
Abstract
Microbial extracellular reduction of insoluble compounds requires soluble electron shuttles that diffuse in the environment, freely diffusing cytochromes, or direct contact with cellular conductive appendages that release or harvest electrons to assure a continuous balance between cellular requirements and environmental conditions. In this work, we produced and characterized the three cytochrome domains of PgcA, an extracellular triheme cytochrome that contributes to Fe(III) and Mn(IV) oxides reduction in Geobacter sulfurreducens. The three monoheme domains are structurally homologous, but their heme groups show variable axial coordination and reduction potential values. Electron transfer experiments monitored by NMR and visible spectroscopy show the variable extent to which the domains promiscuously exchange electrons while reducing different electron acceptors. The results suggest that PgcA is part of a new class of cytochromes - microbial heme-tethered redox strings - that use low-complexity protein stretches to bind metals and promote intra- and intermolecular electron transfer events through its cytochrome domains.
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Affiliation(s)
- Tomás M Fernandes
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal; UCIBIO - Applied Molecular Biosciences Unit, Chemistry Department, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Marta A Silva
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal; UCIBIO - Applied Molecular Biosciences Unit, Chemistry Department, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Leonor Morgado
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal; UCIBIO - Applied Molecular Biosciences Unit, Chemistry Department, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal.
| | - Carlos A Salgueiro
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal; UCIBIO - Applied Molecular Biosciences Unit, Chemistry Department, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal.
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14
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Risgaard-Petersen N, Rotaru AE. Editorial: Electromicrobiology-from electrons to ecosystems, volume II. Front Microbiol 2023; 14:1253550. [PMID: 37555070 PMCID: PMC10405929 DOI: 10.3389/fmicb.2023.1253550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 07/11/2023] [Indexed: 08/10/2023] Open
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15
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Uras IS, Karsli B, Konuklugil B, Ocsoy I, Demirbas A. Organic–Inorganic Nanocomposites of Aspergillus terreus Extract and Its Compounds with Antimicrobial Properties. SUSTAINABILITY 2023; 15:4638. [DOI: 10.3390/su15054638] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/29/2025]
Abstract
Due to its distinct, atypical features and possible applications, three-dimensional (3D) hierarchical nanoflowers have sparked considerable interest. Copper (II) ions were employed as inorganic components in this study, whereas various extracts from Aspergillus terreus and their extracted main components were used as organic components. Extracts from A. terreus and its isolated principal component molecules can first form complexes with copper ions, and these complexes subsequently become nucleation sites for primary copper phosphate crystals, showing interactions using an easy and successful self-assembly template synthesis technique. Therefore, the process results in the formation of 3D nanoflowers among the A. terreus extract and its remoted important additives in addition to copper ions, ensuing in a completely unique round flower-like shape containing loads of nanopetals under the most excellent conditions along with pH, attention of organic–inorganic additives, temperature, and the quantity of copper nitrate on nanoflower formation. Furthermore, A. terreus and its isolated major components, Cu3(PO4)2 nanoflowers, seemed to have a remarkable antibacterial effect. Our findings highlight the benefits of nanoflowers made with A. terreus and its isolated secondary metabolites of inorganic structures, which could be used in industrial biocatalysts, biosensors, and environmental chemistry.
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Affiliation(s)
- Ibrahim Seyda Uras
- Department of Pharmacognosy, Faculty of Pharmacy, Ankara University, Ankara 06560, Turkey
- Department of Pharmacognosy, Faculty of Pharmacy, Agri Ibrahim Cecen University, Agri 04100, Turkey
| | - Baris Karsli
- Department of Seafood Processing Technology, Faculty of Fisheries, Recep Tayyip Erdogan University, Rize 53100, Turkey
| | - Belma Konuklugil
- Department of Pharmacognosy, Faculty of Pharmacy, Ankara University, Ankara 06560, Turkey
- Department of Pharmacognosy, Faculty of Pharmacy, Lokman Hekim University, Ankara 06510, Turkey
| | - Ismail Ocsoy
- Department of Analytical Chemistry, Faculty of Pharmacy, Erciyes University, Kayseri 38039, Turkey
| | - Ayse Demirbas
- Department of Seafood Processing Technology, Faculty of Fisheries, Recep Tayyip Erdogan University, Rize 53100, Turkey
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16
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Wang S, Zhang X, Marsili E. Electrochemical Characteristics of Shewanella loihica PV-4 on Reticulated Vitreous Carbon (RVC) with Different Potentials Applied. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27165330. [PMID: 36014568 PMCID: PMC9413302 DOI: 10.3390/molecules27165330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 08/12/2022] [Accepted: 08/17/2022] [Indexed: 12/24/2022]
Abstract
The current output of an anodic bioelectrochemical system (BES) depends upon the extracellular electron transfer (EET) rate from electricigens to the electrodes. Thus, investigation of EET mechanisms between electricigens and solid electrodes is essential. Here, reticulated vitreous carbon (RVC) electrodes are used to increase the surface available for biofilm formation of the known electricigen Shewanella loihica PV-4, which is limited in conventional flat electrodes. S. loihica PV-4 utilizes flavin-mediated EET at potential lower than the outer membrane cytochromes (OMC), while at higher potential, both direct electron transfer (DET) and mediated electron transfer (MET) contribute to the current output. Results show that high electrode potential favors cell attachment on RVC, which enhances the current output. DET is the prevailing mechanism in early biofilm, while the contribution of MET to current output increased as the biofilm matured. Electrochemical analysis under starvation shows that the mediators could be confined in the biofilm. The morphology of biofilm shows bacteria distributed on the top layer of honeycomb structures, preferentially on the flat areas. This study provides insights into the EET pathways of S. loihica PV-4 on porous RVC electrodes at different biofilm ages and different set potential, which is important for the design of real-world BES.
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Affiliation(s)
- Shixin Wang
- School of Science, Minzu University of China, Beijing 100081, China
| | - Xiaoming Zhang
- School of Science, Minzu University of China, Beijing 100081, China
- Correspondence: (X.Z.); (E.M.)
| | - Enrico Marsili
- Department of Chemical and Materials Engineering, School of Engineering and Digital Sciences, Nazarbayev University, Nur-Sultan 010000, Kazakhstan
- Correspondence: (X.Z.); (E.M.)
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