1
|
Li Y, Cao M, Gupta VK, Wang Y. Metabolic engineering strategies to enable microbial electrosynthesis utilization of CO 2: recent progress and challenges. Crit Rev Biotechnol 2024; 44:352-372. [PMID: 36775662 DOI: 10.1080/07388551.2023.2167065] [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: 06/04/2022] [Revised: 10/17/2022] [Accepted: 12/08/2022] [Indexed: 02/14/2023]
Abstract
Microbial electrosynthesis (MES) is a promising technology that mainly utilizes microbial cells to convert CO2 into value-added chemicals using electrons provided by the cathode. However, the low electron transfer rate is a solid bottleneck hindering the further application of MES. Thus, as an effective strategy, genetic tools play a key role in MES for enhancing the electron transfer rate and diversity of production. We describe a set of genetic strategies based on fundamental characteristics and current successes and discuss their functional mechanisms in driving microbial electrocatalytic reactions to fully comprehend the roles and uses of genetic tools in MES. This paper also analyzes the process of nanomaterial application in extracellular electron transfer (EET). It provides a technique that combines nanomaterials and genetic tools to increase MES efficiency, because nanoparticles have a role in the production of functional genes in EET although genetic tools can subvert MES, it still has issues with difficult transformation and low expression levels. Genetic tools remain one of the most promising future strategies for advancing the MES process despite these challenges.
Collapse
Affiliation(s)
- Yixin Li
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Key Laboratory for Chemical Biology of Fujian Province, Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, China
| | - Mingfeng Cao
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Key Laboratory for Chemical Biology of Fujian Province, Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, China
- Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen, China
| | - Vijai Kumar Gupta
- Biorefining and Advanced Materials Research Center, SRUC, Edinburgh, UK
| | - Yuanpeng Wang
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Key Laboratory for Chemical Biology of Fujian Province, Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, China
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
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.
Collapse
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.
| |
Collapse
|
4
|
Teixeira LR, Fernandes TM, Silva MA, Morgado L, Salgueiro CA. Characterization of a Novel Cytochrome Involved in
Geobacter sulfurreducens’
Electron Harvesting Pathways. Chemistry 2022; 28:e202202333. [DOI: 10.1002/chem.202202333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Indexed: 11/12/2022]
Affiliation(s)
- Liliana R. Teixeira
- Associate Laboratory i4HB-Institute for Health and Bioeconomy NOVA School of Science and Technology NOVA University Lisbon 2819-516 Caparica Portugal
- UCIBIO – Applied Molecular Biosciences Unit, Chemistry Department NOVA School of Science and Technology NOVA University Lisbon 2829-516 Caparica Portugal
| | - Tomás M. Fernandes
- Associate Laboratory i4HB-Institute for Health and Bioeconomy NOVA School of Science and Technology NOVA University Lisbon 2819-516 Caparica Portugal
- UCIBIO – Applied Molecular Biosciences Unit, Chemistry Department NOVA School of Science and Technology NOVA University Lisbon 2829-516 Caparica Portugal
| | - Marta A. Silva
- Associate Laboratory i4HB-Institute for Health and Bioeconomy NOVA School of Science and Technology NOVA University Lisbon 2819-516 Caparica Portugal
- UCIBIO – Applied Molecular Biosciences Unit, Chemistry Department NOVA School of Science and Technology NOVA University Lisbon 2829-516 Caparica Portugal
| | - Leonor Morgado
- Associate Laboratory i4HB-Institute for Health and Bioeconomy NOVA School of Science and Technology NOVA University Lisbon 2819-516 Caparica Portugal
- UCIBIO – Applied Molecular Biosciences Unit, Chemistry Department NOVA School of Science and Technology NOVA University Lisbon 2829-516 Caparica Portugal
| | - Carlos A. Salgueiro
- Associate Laboratory i4HB-Institute for Health and Bioeconomy NOVA School of Science and Technology NOVA University Lisbon 2819-516 Caparica Portugal
- UCIBIO – Applied Molecular Biosciences Unit, Chemistry Department NOVA School of Science and Technology NOVA University Lisbon 2829-516 Caparica Portugal
| |
Collapse
|
5
|
Wu Y, Du Q, Wan Y, Zhao Q, Li N, Wang X. Autotrophic nitrate reduction to ammonium via reverse electron transfer in Geobacter dominated biofilm. Biosens Bioelectron 2022; 215:114578. [PMID: 35868120 DOI: 10.1016/j.bios.2022.114578] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 07/12/2022] [Accepted: 07/14/2022] [Indexed: 01/24/2023]
Abstract
Geobacter dominated electroactive biofilms (EABs) have been demonstrated to perform bidirectional extracellular electron transfer (EET) in bioelectrochemical systems, but it is largely unknown when nitrate is the electron acceptor at the cathode. If reverse EET occurs on biocathode, this EAB has to perform dissimilatory nitrate reduction to ammonia (DNRA) rather than denitrification according to genomes. Here, we have proven the feasibility of reverse bioelectron transfer in EAB, achieving a DNRA efficiency up to 93 ± 3% and high Faraday efficiency of 74 ± 1%. Constant current was found to be more effective than constant potential to maintain Geobacter on the cathode, which highly determines this electrotrophic respiration. The prevalent DNRA at constant current surpassed denitrification, demonstrated by the reverse tendencies of DNRA (nrfA) and denitrification (nirS and nirK) gene transcription. Metatranscriptomics further revealed the possible electron uptake mechanisms by which the outer membrane (OmcZ and OmcB) and periplasmic cytochromes (PpcB and PpcD) may be involved. These findings extend our understanding of the bidirectional electron transfer and advance the applications of EABs.
Collapse
Affiliation(s)
- Yue Wu
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, No. 38 Tongyan Road, Jinnan District, Tianjin, 300350, China
| | - Qing Du
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China
| | - Yuxuan Wan
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, No. 38 Tongyan Road, Jinnan District, Tianjin, 300350, China
| | - Qian Zhao
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, No. 38 Tongyan Road, Jinnan District, Tianjin, 300350, China
| | - Nan Li
- School of Environmental Science and Engineering, Tianjin University, No. 35 Yaguan Road, Jinnan District, Tianjin, 300350, China
| | - Xin Wang
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, No. 38 Tongyan Road, Jinnan District, Tianjin, 300350, China.
| |
Collapse
|
6
|
From iron to bacterial electroconductive filaments: Exploring cytochrome diversity using Geobacter bacteria. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2021.214284] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
|
7
|
Zhu X, Wang X, Li N, Wang Q, Liao C. Bioelectrochemical system for dehalogenation: A review. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 293:118519. [PMID: 34793908 DOI: 10.1016/j.envpol.2021.118519] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/26/2021] [Accepted: 11/13/2021] [Indexed: 06/13/2023]
Abstract
Halogenated organic compounds are persistent pollutants, whose persistent contamination and rapid spread seriously threaten human health and the safety of ecosystems. It is difficult to remove them completely by traditional physicochemical techniques. In-situ remediation utilizing bioelectrochemical technology represents a promising strategy for degradation of halogenated organic compounds, which can be achieved through potential modulation. In this review, we summarize the reactor configuration of microbial electrochemical dehalogenation systems and relevant organohalide-respiring bacteria. We also highlight the mechanisms of electrode potential regulation of microbial dehalogenation and the role of extracellular electron transfer in dehalogenation process, and further discuss the application of bioelectrochemical technology in bioremediation of halogenated organic compounds. Therefore, this review summarizes the status of research on microbial electrochemical dehalogenation systems from macroscopic to microscopic levels, providing theoretical support for the development of rapid and efficient in situ bioremediation technologies for halogenated organic compounds contaminated sites, as well as insights for the removal of refractory fluorides.
Collapse
Affiliation(s)
- Xuemei Zhu
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, No. 38 Tongyan Road, Jinnan District, Tianjin, 300350, China
| | - Xin Wang
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, No. 38 Tongyan Road, Jinnan District, Tianjin, 300350, China
| | - Nan Li
- School of Environmental Science and Engineering, Tianjin University, No. 92 Weijin Road, Nankai District, Tianjin, 300072, China
| | - Qi Wang
- Beijing Construction Engineering Group Environmental Remediation Co. Ltd. and National Engineering Laboratory for Site Remediation Technologies, Beijing, 100015, China
| | - Chengmei Liao
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, No. 38 Tongyan Road, Jinnan District, Tianjin, 300350, China.
| |
Collapse
|
8
|
Structural and functional insights of GSU0105, a unique multiheme cytochrome from G. sulfurreducens. Biophys J 2021; 120:5395-5407. [PMID: 34688593 DOI: 10.1016/j.bpj.2021.10.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 10/01/2021] [Accepted: 10/19/2021] [Indexed: 11/22/2022] Open
Abstract
Geobacter sulfurreducens possesses over 100 cytochromes that assure an effective electron transfer to the cell exterior. The most abundant group of cytochromes in this microorganism is the PpcA family, composed of five periplasmic triheme cytochromes with high structural homology and identical heme coordination (His-His). GSU0105 is a periplasmic triheme cytochrome synthetized by G. sulfurreducens in Fe(III)-reducing conditions but is not present in cultures grown on fumarate. This cytochrome has a low sequence identity with the PpcA family cytochromes and a different heme coordination, based on the analysis of its amino acid sequence. In this work, amino acid sequence analysis, site-directed mutagenesis, and complementary biophysical techniques, including ultraviolet-visible, circular dichroism, electron paramagnetic resonance, and nuclear magnetic resonance spectroscopies, were used to characterize GSU0105. The cytochrome has a low percentage of secondary structural elements, with features of α-helices and β-sheets. Nuclear magnetic resonance shows that the protein contains three low-spin hemes (Fe(II), S = 0) in the reduced state. Electron paramagnetic resonance shows that, in the oxidized state, one of the hemes becomes high-spin (Fe(III), S = 5/2), whereas the two others remain low-spin (Fe(III), S = 1/2). The data obtained also indicate that the heme groups have distinct axial coordination. The apparent midpoint reduction potential of GSU0105 (-154 mV) is pH independent in the physiological range. However, the pH modulates the reduction potential of the heme that undergoes the low- to high-spin interconversion. The reduction potential values of cytochrome GSU0105 are more distinct compared to those of the PpcA family members, providing the protein with a larger functional working redox potential range. Overall, the results obtained, together with an amino acid sequence analysis of different multiheme cytochrome families, indicate that GSU0105 is a member of a new group of triheme cytochromes.
Collapse
|
9
|
Abstract
Extracellular electron transfer (EET) is an important biological process in microbial physiology as found in dissimilatory metal oxidation/reduction and interspecies electron transfer in syntrophy in natural environments. EET also plays a critical role in microorganisms relevant to environmental biotechnology in metal-contaminated areas, metal corrosion, bioelectrochemical systems, and anaerobic digesters. Geobacter species exist in a diversity of natural and artificial environments. One of the outstanding features of Geobacter species is the capability of direct EET with solid electron donors and acceptors, including metals, electrodes, and other cells. Therefore, Geobacter species are pivotal in environmental biogeochemical cycles and biotechnology applications. Geobacter sulfurreducens, a representative Geobacter species, has been studied for direct EET as a model microorganism. G. sulfurreducens employs electrically conductive pili (e-pili) and c-type cytochromes for the direct EET. The biological function and electronics applications of the e-pili have been reviewed recently, and this review focuses on the cytochromes. Geobacter species have an unusually large number of cytochromes encoded in their genomes. Unlike most other microorganisms, Geobacter species localize multiple cytochromes in each subcellular fraction, outer membrane, periplasm, and inner membrane, as well as in the extracellular space, and differentially utilize these cytochromes for EET with various electron donors and acceptors. Some of the cytochromes are functionally redundant. Thus, the EET in Geobacter is complicated. Geobacter coordinates the cytochromes with other cellular components in the elaborate EET system to flourish in the environment.
Collapse
Affiliation(s)
- Toshiyuki Ueki
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA
| |
Collapse
|
10
|
Teixeira LR, Portela PC, Morgado L, Pantoja-Uceda D, Bruix M, Salgueiro CA. Backbone assignment of cytochrome PccH, a crucial protein for microbial electrosynthesis in Geobacter sulfurreducens. BIOMOLECULAR NMR ASSIGNMENTS 2019; 13:321-326. [PMID: 31119489 DOI: 10.1007/s12104-019-09899-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 05/17/2019] [Indexed: 06/09/2023]
Abstract
Microbial electrosynthesis is an emerging green technology that explores the capability of a particular group of microorganisms to drive their metabolism toward the production of hydrogen or value-added chemicals from electrons supplied by electrode surfaces. The cytochrome PccH showed the largest increase in transcription when electrons are supplied to Geobacter sulfurreducens biofilms. Gene knock-out experiments have shown that the electron transfer toward G. sulfurreducens cells was completely inhibited by the deletion of the gene encoding for cytochrome PccH. This identifies a crucial role for this protein in G. sulfurreducens microbial electrosynthesis mechanisms, which are currently unknown. In this work, we present the backbone (1H, 13C and 15N) and heme assignment for PccH in the oxidized state. The data obtained paves the way to identify and structurally map the molecular interaction regions between the cytochrome PccH and its physiological redox partners.
Collapse
Affiliation(s)
- Liliana R Teixeira
- UCIBIO-Requimte, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Campus Caparica, 2829-516, Caparica, Portugal
| | - Pilar C Portela
- UCIBIO-Requimte, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Campus Caparica, 2829-516, Caparica, Portugal
| | - Leonor Morgado
- UCIBIO-Requimte, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Campus Caparica, 2829-516, Caparica, Portugal
| | - David Pantoja-Uceda
- Departamento de Química Física Biológica, Instituto de Química-Física ''Rocasolano'', CSIC, Serrano 119, 28006, Madrid, Spain
| | - Marta Bruix
- Departamento de Química Física Biológica, Instituto de Química-Física ''Rocasolano'', CSIC, Serrano 119, 28006, Madrid, Spain.
| | - Carlos A Salgueiro
- UCIBIO-Requimte, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Campus Caparica, 2829-516, Caparica, Portugal.
| |
Collapse
|
11
|
Dantas JM, Portela PC, Fernandes AP, Londer YY, Yang X, Duke NEC, Schiffer M, Pokkuluri PR, Salgueiro CA. Structural and Functional Relevance of the Conserved Residue V13 in the Triheme Cytochrome PpcA from Geobacter sulfurreducens. J Phys Chem B 2019; 123:3050-3060. [PMID: 30875222 DOI: 10.1021/acs.jpcb.9b01214] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The triheme cytochrome PpcA from Geobacter sulfurreducens is highly abundant under several growth conditions and is important for extracellular electron transfer. PpcA plays a central role in transferring electrons resulting from the cytoplasmic oxidation of carbon compounds to the cell exterior. This cytochrome is designed to couple electron and proton transfer at physiological pH, a process achieved via the selection of dominant microstates during the redox cycle of the protein, which are ultimately regulated by a well-established order of oxidation of the heme groups. The three hemes are covered only by a polypeptide chain of 71 residues and are located in the small hydrophobic core of the protein. In this work, we used NMR and X-ray crystallography to investigate the structural and functional role of a conserved valine residue (V13) located within van der Waals contact of hemes III and IV. The residue was replaced by alanine (V13A), isoleucine (V13I), serine (V13S), and threonine (V13T) to probe the effects of the side chain volume and polarity. All mutants were found to be as equally thermally stable as the native protein. The V13A and V13T mutants produced crystals and their structures were determined. The side chain of the threonine residue introduced in V13T showed two conformations, but otherwise the two structures did not show significant changes from the native structure. Analysis of the redox behavior of the four mutants showed that for the hydrophobic replacements (V13A and V13I) the redox properties, and hence the order of oxidation of the hemes, were unaffected in spite of the larger side chain, isoleucine, showing two conformations with minor changes of the protein in the heme core. On the other hand, the polar replacements (V13S and V13T) showed the presence of two more distinctive conformations, and the oxidation order of the hemes was altered. Overall, it is striking that a single residue with proper size and polarity, V13, was naturally selected to ensure a unique conformation of the protein and the order of oxidation of the hemes, endowing the cytochrome PpcA with the optimal functional properties necessary to ensure effectiveness in the extracellular electron transfer respiratory pathways of G. sulfurreducens.
Collapse
Affiliation(s)
- Joana M Dantas
- UCIBIO-Requimte, Departamento de Química , Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa , Campus Caparica, 2829-516 Caparica , Portugal
| | - Pilar C Portela
- UCIBIO-Requimte, Departamento de Química , Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa , Campus Caparica, 2829-516 Caparica , Portugal
| | - Ana P Fernandes
- UCIBIO-Requimte, Departamento de Química , Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa , Campus Caparica, 2829-516 Caparica , Portugal
| | - Yuri Y Londer
- Biosciences Division , Argonne National Laboratory , 9700 South Cass Avenue , Argonne , Illinois 60439 , United States
| | - Xiaojing Yang
- Biosciences Division , Argonne National Laboratory , 9700 South Cass Avenue , Argonne , Illinois 60439 , United States
| | - Norma E C Duke
- Biosciences Division , Argonne National Laboratory , 9700 South Cass Avenue , Argonne , Illinois 60439 , United States
| | - Marianne Schiffer
- Biosciences Division , Argonne National Laboratory , 9700 South Cass Avenue , Argonne , Illinois 60439 , United States
| | - P Raj Pokkuluri
- Biosciences Division , Argonne National Laboratory , 9700 South Cass Avenue , Argonne , Illinois 60439 , United States
| | - Carlos A Salgueiro
- UCIBIO-Requimte, Departamento de Química , Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa , Campus Caparica, 2829-516 Caparica , Portugal
| |
Collapse
|
12
|
Zou L, Qiao Y, Li CM. Boosting Microbial Electrocatalytic Kinetics for High Power Density: Insights into Synthetic Biology and Advanced Nanoscience. ELECTROCHEM ENERGY R 2018. [DOI: 10.1007/s41918-018-0020-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
13
|
Silveira CM, Castro MA, Dantas JM, Salgueiro C, Murgida DH, Todorovic S. Structure, electrocatalysis and dynamics of immobilized cytochrome PccH and its microperoxidase. Phys Chem Chem Phys 2018; 19:8908-8918. [PMID: 28295106 DOI: 10.1039/c6cp08361g] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Geobacter sulfurreducens cells have the ability to exchange electrons with conductive materials, and the periplasmic cytochrome PccH plays an essential role in the direct electrode-to-cell electron transfer in this bacterium. It has atypically low redox potential and unique structural features that differ from those observed in other c-type cytochromes. We report surface enhanced resonance Raman spectroscopic and electrochemical characterization of the immobilized PccH, together with molecular dynamics simulations that allow for the rationalization of experimental observations. Upon attachment to electrodes functionalized with partially or fully hydrophobic self-assembled monolayers, PccH displays a distribution of native and non-native heme spin configurations, similar to those observed in horse heart cytochrome c. The native structural and thermodynamic features of PccH are preserved upon attachment mixed hydrophobic (-CH3/-NH2) surfaces, while pure -OH, -NH2 and -COOH surfaces do not provide suitable platforms for its adsorption, indicating that its still unknown physiological redox partner might be membrane integrated. Neither of the employed immobilization strategies results in electrocatalytically active PccH capable of the reduction of hydrogen peroxide. Pseudoperoxidase activity is observed in immobilized microperoxidase, which is enzymatically produced from PccH and spectroscopically characterized. Further improvement of PccH microperoxidase stability is required for its application in electrochemical biosensing of hydrogen peroxide.
Collapse
Affiliation(s)
- Célia M Silveira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Av. da República, 2780-157 Oeiras, Portugal. and UCIBIO, REQUIMTE, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Monte de Caparica, Portugal
| | - María A Castro
- Departamento de Química Inorgánica, Analítica y Química Física and INQUIMAE (CONICET-UBA), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina
| | - Joana M Dantas
- UCIBIO, REQUIMTE, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Monte de Caparica, Portugal
| | - Carlos Salgueiro
- UCIBIO, REQUIMTE, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Monte de Caparica, Portugal
| | - Daniel H Murgida
- Departamento de Química Inorgánica, Analítica y Química Física and INQUIMAE (CONICET-UBA), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina
| | - Smilja Todorovic
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Av. da República, 2780-157 Oeiras, Portugal.
| |
Collapse
|
14
|
Shin HJ, Jung KA, Nam CW, Park JM. A genetic approach for microbial electrosynthesis system as biocommodities production platform. BIORESOURCE TECHNOLOGY 2017; 245:1421-1429. [PMID: 28550992 DOI: 10.1016/j.biortech.2017.05.077] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 05/12/2017] [Accepted: 05/14/2017] [Indexed: 06/07/2023]
Abstract
Microbial electrosynthesis is a process that can produce biocommodities from the reduction of substrates with microbial catalysts and an external electron supply. This process is expected to become a new application of a cell factory for novel chemical production, wastewater treatment, and carbon capture and utilization. However, microbial electrosynthesis is still subject to several problems that need to be overcome for commercialization, so continuous development such as metabolic engineering is essential. The development of microbial electrosynthesis can open up new opportunities for sustainable biocommodities production platforms. This review provides significant information on the current state of MES development, focusing on extracellularly electron transfer and metabolic engineering.
Collapse
Affiliation(s)
- Hyo Jeong Shin
- Department of Chemical Engineering, POSTECH, 77 Cheongam-ro, Nam-gu, Pohang 37673, South Korea
| | - Kyung A Jung
- Bioenergy Research Center, POSTECH, 77 Cheongam-ro, Nam-gu, Pohang 37673, South Korea
| | - Chul Woo Nam
- Department of Chemical Engineering, POSTECH, 77 Cheongam-ro, Nam-gu, Pohang 37673, South Korea
| | - Jong Moon Park
- Department of Chemical Engineering, POSTECH, 77 Cheongam-ro, Nam-gu, Pohang 37673, South Korea; Bioenergy Research Center, POSTECH, 77 Cheongam-ro, Nam-gu, Pohang 37673, South Korea; Division of Advanced Nuclear Engineering, POSTECH, 77 Cheongam-ro, Nam-gu, Pohang 37673, South Korea.
| |
Collapse
|
15
|
Choi O, Sang BI. Extracellular electron transfer from cathode to microbes: application for biofuel production. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:11. [PMID: 27034716 PMCID: PMC4717640 DOI: 10.1186/s13068-016-0426-0] [Citation(s) in RCA: 135] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 01/05/2016] [Indexed: 05/07/2023]
Abstract
Extracellular electron transfer in microorganisms has been applied for bioelectrochemical synthesis utilizing microbes to catalyze anodic and/or cathodic biochemical reactions. Anodic reactions (electron transfer from microbe to anode) are used for current production and cathodic reactions (electron transfer from cathode to microbe) have recently been applied for current consumption for valuable biochemical production. The extensively studied exoelectrogenic bacteria Shewanella and Geobacter showed that both directions for electron transfer would be possible. It was proposed that gram-positive bacteria, in the absence of cytochrome C, would accept electrons using a cascade of membrane-bound complexes such as membrane-bound Fe-S proteins, oxidoreductase, and periplasmic enzymes. Modification of the cathode with the addition of positive charged species such as chitosan or with an increase of the interfacial area using a porous three-dimensional scaffold electrode led to increased current consumption. The extracellular electron transfer from the cathode to the microbe could catalyze various bioelectrochemical reductions. Electrofermentation used electrons from the cathode as reducing power to produce more reduced compounds such as alcohols than acids, shifting the metabolic pathway. Electrofuel could be generated through artificial photosynthesis using electrical energy instead of solar energy in the process of carbon fixation.
Collapse
Affiliation(s)
- Okkyoung Choi
- Department of Chemical Engineering, Hanyang University, 222 Wangshimni-ro, Seongdong-gu, Seoul, 04763 South Korea
| | - Byoung-In Sang
- Department of Chemical Engineering, Hanyang University, 222 Wangshimni-ro, Seongdong-gu, Seoul, 04763 South Korea
| |
Collapse
|
16
|
Santos TC, de Oliveira AR, Dantas JM, Salgueiro CA, Cordas CM. Thermodynamic and kinetic characterization of PccH, a key protein in microbial electrosynthesis processes in Geobacter sulfurreducens. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:1113-8. [DOI: 10.1016/j.bbabio.2015.06.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 05/29/2015] [Accepted: 06/07/2015] [Indexed: 10/23/2022]
|
17
|
Dantas JM, Campelo LM, Duke NEC, Salgueiro CA, Pokkuluri PR. The structure of PccH from Geobacter sulfurreducens - a novel low reduction potential monoheme cytochrome essential for accepting electrons from an electrode. FEBS J 2015; 282:2215-31. [PMID: 25786707 DOI: 10.1111/febs.13269] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 02/09/2015] [Accepted: 03/13/2015] [Indexed: 11/27/2022]
Abstract
The structure of cytochrome c (GSU3274) designated as PccH from Geobacter sulfurreducens was determined at a resolution of 2.0 Å. PccH is a small (15 kDa) cytochrome containing one c-type heme, found to be essential for the growth of G. sulfurreducens with respect to accepting electrons from graphite electrodes poised at -300 mV versus standard hydrogen electrode. with fumarate as the terminal electron acceptor. The structure of PccH is unique among the monoheme cytochromes described to date. The structural fold of PccH can be described as forming two lobes with the heme sandwiched in a cleft between the two lobes. In addition, PccH has a low reduction potential of -24 mV at pH 7, which is unusual for monoheme cytochromes. Based on difference in structure, together with sequence phylogenetic analysis, we propose that PccH can be regarded as a first characterized example of a new subclass of class I monoheme cytochromes. The low reduction potential of PccH may enable the protein to be redox active at the typically negative potential ranges encountered by G. sulfurreducens. Because PccH is predicted to be located in the periplasm of this bacterium, it could not be involved in the first step of accepting electrons from the electrode but is very likely involved in the downstream electron transport events in the periplasm.
Collapse
Affiliation(s)
- Joana M Dantas
- UCIBIO - REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Luísa M Campelo
- UCIBIO - REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Norma E C Duke
- Biosciences Division, Argonne National Laboratory, Lemont, IL, USA
| | - Carlos A Salgueiro
- UCIBIO - REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - P Raj Pokkuluri
- Biosciences Division, Argonne National Laboratory, Lemont, IL, USA
| |
Collapse
|