1
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Florek LC, Lin X, Lin YC, Lin MH, Chakraborty A, Price-Whelan A, Tong L, Rahme L, Dietrich LEP. The L-lactate dehydrogenases of Pseudomonas aeruginosa are conditionally regulated but both contribute to survival during macrophage infection. mBio 2024; 15:e0085224. [PMID: 39162563 PMCID: PMC11389411 DOI: 10.1128/mbio.00852-24] [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: 03/20/2024] [Accepted: 07/09/2024] [Indexed: 08/21/2024] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that thrives in environments associated with human activity, including soil and water altered by agriculture or pollution. Because L-lactate is a significant product of plant and animal metabolism, it can serve as a carbon source for P. aeruginosa in the diverse settings that it inhabits. In this study, we evaluate the production and use of two redundant P. aeruginosa L-lactate dehydrogenases, termed LldD and LldA. We confirm that the protein LldR represses lldD and identify a new transcription factor, called LldS, that activates lldA; these distinct regulators and the genomic contexts of lldD and lldA contribute to their differential expression. We demonstrate that the lldD and lldA genes are conditionally controlled in response to lactate isomers as well as to glycolate and ɑ-hydroxybutyrate, which, like lactate, are ɑ-hydroxycarboxylates. We also show that lldA is induced when iron availability is low. Our examination of lldD and lldA expression across depth in biofilms indicates a complex pattern that is consistent with the effects of glycolate production, iron availability, and cross-regulation on enzyme preference. Finally, macrophage infection assays reveal that both lldD and lldA contribute to persistence within host cells, underscoring the potential role of L-lactate as a carbon source during P. aeruginosa-eukaryote interactions. Together, these findings help us understand the metabolism of a key resource that may promote P. aeruginosa's success as a resident of contaminated environments and animal hosts.IMPORTANCEPseudomonas aeruginosa is a major cause of lung infections in people with cystic fibrosis, of hospital-acquired infections, and of wound infections. It consumes L-lactate, which is found at substantial levels in human blood and tissues. In this study, we investigated the spatial regulation of two redundant enzymes, called LldD and LldA, which enable L-lactate metabolism in P. aeruginosa biofilms. We uncovered mechanisms and identified compounds that control the preference of P. aeruginosa for LldD versus LldA. We also showed that both enzymes contribute to its ability to survive within macrophages, a behavior that is thought to augment the chronicity and recalcitrance of infections. Our findings shed light on a key metabolic strategy used by P. aeruginosa and have the potential to inform the development of therapies targeting bacterial metabolism during infection.
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Affiliation(s)
- Lindsey C Florek
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Xi Lin
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Yu-Cheng Lin
- Department of Dentistry, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Min-Han Lin
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Arijit Chakraborty
- Department of Surgery, Massachusetts General Hospital, and Harvard Medical School, Boston, Massachusetts, USA
- Shriners Hospitals for Children Boston, Boston, Massachusetts, USA
| | - Alexa Price-Whelan
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Liang Tong
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Laurence Rahme
- Department of Surgery, Massachusetts General Hospital, and Harvard Medical School, Boston, Massachusetts, USA
- Shriners Hospitals for Children Boston, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Lars E P Dietrich
- Department of Biological Sciences, Columbia University, New York, New York, USA
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2
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Florek LC, Lin X, Lin YC, Lin MH, Chakraborty A, Price-Whelan A, Tong L, Rahme L, Dietrich LE. The L-lactate dehydrogenases of Pseudomonas aeruginosa are conditionally regulated but both contribute to survival during macrophage infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.21.586142. [PMID: 38562866 PMCID: PMC10983889 DOI: 10.1101/2024.03.21.586142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that thrives in environments associated with human activity, including soil and water altered by agriculture or pollution. Because L-lactate is a significant product of plant and animal metabolism, it is available to serve as a carbon source for P. aeruginosa in the diverse settings it inhabits. Here, we evaluate P. aeruginosa's production and use of its redundant L-lactate dehydrogenases, termed LldD and LldA. We confirm that the protein LldR represses lldD and identify a new transcription factor, called LldS, that activates lldA; these distinct regulators and the genomic contexts of lldD and lldA contribute to their differential expression. We demonstrate that the lldD and lldA genes are conditionally controlled in response to lactate isomers as well as to glycolate and - hydroxybutyrate, which, like lactate, are -hydroxycarboxylates. We also show that lldA is induced when iron availability is low. Our examination of lldD and lldA expression across depth in biofilms indicates a complex pattern that is consistent with the effects of glycolate production, iron availability, and cross-regulation on enzyme preference. Finally, macrophage infection assays revealed that both lldD and lldA contribute to persistence within host cells, underscoring the potential role of L-lactate as a carbon source during P. aeruginosa-eukaryote interactions. Together, these findings help us understand the metabolism of a key resource that may promote P. aeruginosa's success as a resident of contaminated environments and animal hosts.
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Affiliation(s)
- Lindsey C. Florek
- Department of Biological Sciences, Columbia University, New York, NY 10027
| | - Xi Lin
- Department of Biological Sciences, Columbia University, New York, NY 10027
| | - Yu-Cheng Lin
- Department of Dentistry, National Yang Ming Chiao Tung University, Taipei, Taiwan 112
| | - Min-Han Lin
- Department of Biological Sciences, Columbia University, New York, NY 10027
| | - Arijit Chakraborty
- Department of Surgery, Massachusetts General Hospital, and Harvard Medical School, Boston, Massachusetts, USA
- Shriners Hospitals for Children Boston, Boston, Massachusetts, USA
| | - Alexa Price-Whelan
- Department of Biological Sciences, Columbia University, New York, NY 10027
| | - Liang Tong
- Department of Biological Sciences, Columbia University, New York, NY 10027
| | - Laurence Rahme
- Department of Surgery, Massachusetts General Hospital, and Harvard Medical School, Boston, Massachusetts, USA
- Shriners Hospitals for Children Boston, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Lars E.P. Dietrich
- Department of Biological Sciences, Columbia University, New York, NY 10027
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3
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Mayo-Pérez S, Gama-Martínez Y, Dávila S, Rivera N, Hernández-Lucas I. LysR-type transcriptional regulators: state of the art. Crit Rev Microbiol 2023:1-33. [PMID: 37635411 DOI: 10.1080/1040841x.2023.2247477] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 08/03/2023] [Accepted: 08/08/2023] [Indexed: 08/29/2023]
Abstract
The LysR-type transcriptional regulators (LTTRs) are DNA-binding proteins present in bacteria, archaea, and in algae. Knowledge about their distribution, abundance, evolution, structural organization, transcriptional regulation, fundamental roles in free life, pathogenesis, and bacteria-plant interaction has been generated. This review focuses on these aspects and provides a current picture of LTTR biology.
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Affiliation(s)
- S Mayo-Pérez
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Y Gama-Martínez
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - S Dávila
- Centro de Investigación en Dinámica Celular, Universidad Autónoma del Estado de Morelos, Cuernavaca, Mexico
| | - N Rivera
- IPN: CICATA, Unidad Morelos del Instituto Politécnico Nacional, Atlacholoaya, Mexico
| | - I Hernández-Lucas
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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4
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Jiang YJ, Hui S, Tian S, Chen Z, Chai Y, Jiang LP, Zhang JR, Zhu JJ. Enhanced transmembrane electron transfer in Shewanella oneidensis MR-1 using gold nanoparticles for high-performance microbial fuel cells. NANOSCALE ADVANCES 2022; 5:124-132. [PMID: 36605799 PMCID: PMC9765428 DOI: 10.1039/d2na00638c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Accepted: 11/09/2022] [Indexed: 06/17/2023]
Abstract
Low efficiency of extracellular electron transfer (EET) is a major bottleneck in developing high-performance microbial fuel cells (MFCs). Herein, we construct Shewanella oneidensis MR-1@Au for the bioanode of MFCs. Through performance recovery experiments of mutants, we proved that abundant Au nanoparticles not only tightly covered the bacteria surface, but were also distributed in the periplasm and cytoplasm, and even embedded in the outer and inner membranes of the cell. These Au nanoparticles could act as electron conduits to enable highly efficient electron transfer between S. oneidensis MR-1 and electrodes. Strikingly, the maximum power density of the S. oneidensis MR-1@Au bioanode reached up to 3749 mW m-2, which was 17.4 times higher than that with the native bacteria, reaching the highest performance yet reported in MFCs using Au or Au-based nanocomposites as the anode. This work elucidates the role of Au nanoparticles in promoting transmembrane and extracellular electron transfer from the perspective of molecular biology and electrochemistry, while alleviating bottlenecks in MFC performances.
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Affiliation(s)
- Yu-Jing Jiang
- State Key Laboratory of Analytical Chemistry for Life Science, State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 PR China
| | - Su Hui
- State Key Laboratory of Analytical Chemistry for Life Science, State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 PR China
| | - Shihao Tian
- State Key Laboratory of Analytical Chemistry for Life Science, State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 PR China
| | - Zixuan Chen
- State Key Laboratory of Analytical Chemistry for Life Science, State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 PR China
| | - Yifan Chai
- State Key Laboratory of Analytical Chemistry for Life Science, State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 PR China
| | - Li-Ping Jiang
- State Key Laboratory of Analytical Chemistry for Life Science, State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 PR China
| | - Jian-Rong Zhang
- State Key Laboratory of Analytical Chemistry for Life Science, State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 PR China
| | - Jun-Jie Zhu
- State Key Laboratory of Analytical Chemistry for Life Science, State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 PR China
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5
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Ford K, Kaste JAM, Shachar-Hill Y, TerAvest MA. Flux-Balance Analysis and Mobile CRISPRi-Guided Deletion of a Conditionally Essential Gene in Shewanella oneidensis MR-1. ACS Synth Biol 2022; 11:3405-3413. [PMID: 36219726 PMCID: PMC9595118 DOI: 10.1021/acssynbio.2c00323] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Indexed: 01/24/2023]
Abstract
Carbon-neutral production of valuable bioproducts is critical to sustainable development but remains limited by the slow engineering of photosynthetic organisms. Improving existing synthetic biology tools to engineer model organisms to fix carbon dioxide is one route to overcoming the limitations of photosynthetic organisms. In this work, we describe a pipeline that enabled the deletion of a conditionally essential gene from the Shewanella oneidensis MR-1 genome. S. oneidensis is a simple bacterial host that could be used for electricity-driven conversion of carbon dioxide in the future with further genetic engineering. We used Flux Balance Analysis (FBA) to model carbon and energy flows in central metabolism and assess the effects of single and double gene deletions. We modeled the growth of deletion strains under several alternative conditions to identify substrates that restore viability to an otherwise lethal gene knockout. These predictions were tested in vivo using a Mobile-CRISPRi gene knockdown system. The information learned from FBA and knockdown experiments informed our strategy for gene deletion, allowing us to successfully delete an "expected essential" gene, gpmA. FBA predicted, knockdown experiments supported, and deletion confirmed that the "essential" gene gpmA is not needed for survival, dependent on the medium used. Removal of gpmA is a first step toward driving electrode-powered CO2 fixation via RuBisCO. This work demonstrates the potential for broadening the scope of genetic engineering in S. oneidensis as a synthetic biology chassis. By combining computational analysis with a CRISPRi knockdown system in this way, one can systematically assess the impact of conditionally essential genes and use this knowledge to generate mutations previously thought unachievable.
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Affiliation(s)
- Kathryne
C. Ford
- Department
of Biochemistry and Molecular Biology, Michigan
State University, East Lansing, Michigan 48824, United States
- Department
of Microbiology and Molecular Genetics, Michigan State University, East
Lansing, Michigan 48824, United States
| | - Joshua A. M. Kaste
- Department
of Biochemistry and Molecular Biology, Michigan
State University, East Lansing, Michigan 48824, United States
- Department
of Plant Biology, Michigan State University, East Lansing, Michigan 48824, United States
| | - Yair Shachar-Hill
- Department
of Plant Biology, Michigan State University, East Lansing, Michigan 48824, United States
| | - Michaela A. TerAvest
- Department
of Biochemistry and Molecular Biology, Michigan
State University, East Lansing, Michigan 48824, United States
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6
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Yu YY, Zhen SH, Chao SL, Wu J, Cheng L, Li SW, Xiao X, Zhou X. Electrochemistry of newly isolated Gram-positive bacteria Paenibacillus lautus with starch as sole carbon source. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2022.140068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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7
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Partipilo G, Graham AJ, Belardi B, Keitz BK. Extracellular Electron Transfer Enables Cellular Control of Cu(I)-Catalyzed Alkyne-Azide Cycloaddition. ACS CENTRAL SCIENCE 2022; 8:246-257. [PMID: 35233456 PMCID: PMC8875427 DOI: 10.1021/acscentsci.1c01208] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Indexed: 05/03/2023]
Abstract
Extracellular electron transfer (EET) is an anaerobic respiration process that couples carbon oxidation to the reduction of metal species. In the presence of a suitable metal catalyst, EET allows for cellular metabolism to control a variety of synthetic transformations. Here, we report the use of EET from the electroactive bacterium Shewanella oneidensis for metabolic and genetic control over Cu(I)-catalyzed alkyne-azide cycloaddition (CuAAC). CuAAC conversion under anaerobic and aerobic conditions was dependent on live, actively respiring S. oneidensis cells. The reaction progress and kinetics were manipulated by tailoring the central carbon metabolism. Similarly, EET-CuAAC activity was dependent on specific EET pathways that could be regulated via inducible expression of EET-relevant proteins: MtrC, MtrA, and CymA. EET-driven CuAAC exhibited modularity and robustness in the ligand and substrate scope. Furthermore, the living nature of this system could be exploited to perform multiple reaction cycles without regeneration, something inaccessible to traditional chemical reductants. Finally, S. oneidensis enabled bioorthogonal CuAAC membrane labeling on live mammalian cells without affecting cell viability, suggesting that S. oneidensis can act as a dynamically tunable biocatalyst in complex environments. In summary, our results demonstrate how EET can expand the reaction scope available to living systems by enabling cellular control of CuAAC.
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Affiliation(s)
- Gina Partipilo
- McKetta
Department of Chemical Engineering, University
of Texas at Austin, Austin, Texas 78712, United States
- Center
for Dynamics and Control of Materials, University
of Texas at Austin, Austin, Texas 78712, United States
| | - Austin J. Graham
- McKetta
Department of Chemical Engineering, University
of Texas at Austin, Austin, Texas 78712, United States
- Center
for Dynamics and Control of Materials, University
of Texas at Austin, Austin, Texas 78712, United States
| | - Brian Belardi
- McKetta
Department of Chemical Engineering, University
of Texas at Austin, Austin, Texas 78712, United States
| | - Benjamin K. Keitz
- McKetta
Department of Chemical Engineering, University
of Texas at Austin, Austin, Texas 78712, United States
- Center
for Dynamics and Control of Materials, University
of Texas at Austin, Austin, Texas 78712, United States
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8
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Augustiniene E, Malys N. Identification and characterization of L- and D-lactate-inducible systems from Escherichia coli MG1655, Cupriavidus necator H16 and Pseudomonas species. Sci Rep 2022; 12:2123. [PMID: 35136142 PMCID: PMC8827060 DOI: 10.1038/s41598-022-06028-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 01/17/2022] [Indexed: 12/22/2022] Open
Abstract
Lactic acid is an important platform chemical used for the production of various compounds including polylactic acid (PLA). Optically pure L- and D-lactic acids are required to obtain high quality PLA. To advance the development and selection of microbial strains for improved production of lactic acid enantiomers, a high-throughput screening, dynamic pathway control, or real-time monitoring are often applied. Inducible gene expression systems and their application in the genetically encoded biosensors contribute to the development of these techniques and are important devices for the advancement of lactic acid biotechnology. Here, we identify and characterize eleven lactate-inducible systems from Escherichia coli, Cupriavidus necator, and Pseudomonas spp. The specificity and dynamics of these systems in response to L- and D-lactate, or structurally similar compounds are investigated. We demonstrate that the inducible systems EcLldR/PlldP and CnGntR/PH16_RS19190 respond only to the L-lactate, exhibiting approximately 19- and 24-fold induction, respectively. Despite neither of the examined bacteria possess the D-lactate-specific inducible system, the PaPdhR/PlldP and PfPdhR/PlldP are induced approximately 37- and 366-fold, respectively, by D-lactate and can be used for developing biosensor with improved specificity. The findings of this study provide an insight into understanding of L- and D-lactate-inducible systems that can be employed as sensing and tuneable devices in synthetic biology.
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Affiliation(s)
- Ernesta Augustiniene
- Bioprocess Research Centre, Faculty of Chemical Technology, Kaunas University of Technology, Radvilėnų pl. 19, Kaunas, LT-50254, Lithuania
| | - Naglis Malys
- Bioprocess Research Centre, Faculty of Chemical Technology, Kaunas University of Technology, Radvilėnų pl. 19, Kaunas, LT-50254, Lithuania. .,Department of Organic Chemistry, Faculty of Chemical Technology, Kaunas University of Technology, Radvilėnų pl. 19, Kaunas, LT-50254, Lithuania.
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9
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Cao B, Zhao Z, Peng L, Shiu HY, Ding M, Song F, Guan X, Lee CK, Huang J, Zhu D, Fu X, Wong GCL, Liu C, Nealson K, Weiss PS, Duan X, Huang Y. Silver nanoparticles boost charge-extraction efficiency in Shewanella microbial fuel cells. Science 2021; 373:1336-1340. [PMID: 34529487 DOI: 10.1126/science.abf3427] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Bocheng Cao
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA.,Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Zipeng Zhao
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Lele Peng
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Hui-Ying Shiu
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Mengning Ding
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Frank Song
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Xun Guan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Calvin K Lee
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Jin Huang
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Dan Zhu
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Xiaoyang Fu
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Gerard C L Wong
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Chong Liu
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Kenneth Nealson
- Department of Earth Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Paul S Weiss
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA.,Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA.,Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90095, USA.,California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Xiangfeng Duan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA.,California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Yu Huang
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA.,California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
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10
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Kees ED, Levar CE, Miller SP, Bond DR, Gralnick JA, Dean AM. Survival of the first rather than the fittest in a Shewanella electrode biofilm. Commun Biol 2021; 4:536. [PMID: 33958697 PMCID: PMC8102560 DOI: 10.1038/s42003-021-02040-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 03/22/2021] [Indexed: 11/09/2022] Open
Abstract
For natural selection to operate there must exist heritable variation among individuals that affects their survival and reproduction. Among free-living microbes, where differences in growth rates largely define selection intensities, competitive exclusion is common. However, among surface attached communities, these dynamics become less predictable. If extreme circumstances were to dictate that a surface population is immortal and all offspring must emigrate, the offspring would be unable to contribute to the composition of the population. Meanwhile, the immortals, regardless of reproductive capacity, would remain unchanged in relative abundance. The normal cycle of birth, death, and competitive exclusion would be broken. We tested whether conditions required to set up this idealized scenario can be approximated in a microbial biofilm. Using two differentially-reproducing strains of Shewanella oneidensis grown on an anode as the sole terminal electron acceptor - a system in which metabolism is obligately tied to surface attachment - we found that selection against a slow-growing competitor is drastically reduced. This work furthers understanding of natural selection dynamics in sessile microbial communities, and provides a framework for designing stable microbial communities for industrial and experimental applications.
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Affiliation(s)
- Eric D Kees
- BioTechnology Institute, University of Minnesota, St Paul, MN, USA
- Department of Plant and Microbial Biology, University of Minnesota, St Paul, MN, USA
| | - Caleb E Levar
- BioTechnology Institute, University of Minnesota, St Paul, MN, USA
- Department of Plant and Microbial Biology, University of Minnesota, St Paul, MN, USA
| | - Stephen P Miller
- BioTechnology Institute, University of Minnesota, St Paul, MN, USA
- Department of Ecology, Evolution and Behavior, University of Minnesota, St Paul, MN, USA
| | - Daniel R Bond
- BioTechnology Institute, University of Minnesota, St Paul, MN, USA
- Department of Plant and Microbial Biology, University of Minnesota, St Paul, MN, USA
| | - Jeffrey A Gralnick
- BioTechnology Institute, University of Minnesota, St Paul, MN, USA.
- Department of Plant and Microbial Biology, University of Minnesota, St Paul, MN, USA.
| | - Antony M Dean
- BioTechnology Institute, University of Minnesota, St Paul, MN, USA.
- Department of Ecology, Evolution and Behavior, University of Minnesota, St Paul, MN, USA.
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11
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Hirose A, Kouzuma A, Watanabe K. Towards development of electrogenetics using electrochemically active bacteria. Biotechnol Adv 2019; 37:107351. [DOI: 10.1016/j.biotechadv.2019.02.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 01/09/2019] [Accepted: 02/15/2019] [Indexed: 12/20/2022]
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12
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Development of a longevous two-species biophotovoltaics with constrained electron flow. Nat Commun 2019; 10:4282. [PMID: 31537786 PMCID: PMC6753107 DOI: 10.1038/s41467-019-12190-w] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Accepted: 08/27/2019] [Indexed: 01/07/2023] Open
Abstract
Microbial biophotovoltaics (BPV) offers a biological solution for renewable energy production by using photosynthetic microorganisms as light absorbers. Although abiotic engineering approaches, e.g., electrode modification and device optimization, can enhance the electrochemical communication between living cells and electrodes, the power densities of BPV are still low due to the weak exoelectrogenic activity of photosynthetic microorganisms. Here, we develop a BPV based on a D-lactate mediated microbial consortium consisting of photosynthetic cyanobacteria and exoelectrogenic Shewanella. By directing solar energy from photons to D-lactate, then to electricity, this BPV generates a power density of over 150 mW·m-2 in a temporal separation setup. Furthermore, a spatial-temporal separation setup with medium replenishment enables stable operation for over 40 days with an average power density of 135 mW·m-2. These results demonstrate the electron flow constrained microbial consortium can facilitate electron export from photosynthetic cells and achieve an efficient and durable power output.
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13
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Singh K, Ainala SK, Kim Y, Park S. A novel D(-)-lactic acid-inducible promoter regulated by the GntR-family protein D-LldR of Pseudomonas fluorescens. Synth Syst Biotechnol 2019; 4:157-164. [PMID: 31517075 PMCID: PMC6731338 DOI: 10.1016/j.synbio.2019.08.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 08/23/2019] [Accepted: 08/26/2019] [Indexed: 11/26/2022] Open
Abstract
Lactic acid has two stereoisomers of D(-)- and L(+)-forms, both of which are important monomers of biodegradable plastic, poly-lactic acid. In this study, a novel d-lactate inducible system was identified in Pseudomonas fluorescens A506, partially characterized and tested as biosensor. The d-lactate catabolic operon (lldP-dld-II) was negatively regulated through the inversely transcribed D-lldR (encoding a GntR-type regulator), where the repression is relieved by addition of d-lactate. The derepression was specific to d-lactate and marginally affected by l-lactate. The D-LldR-responsive operator, showing dyad symmetry and separated by one base, was located between +11 and + 27 from the transcription start site of the lldP-dld-II operon. By site-directed mutagenesis, a motif with a dyad symmetry (AATTGGTAtTACCAATT), present in the upstream region of lldP, was identified as essential for the binding of LldR. d-lactate biosensors were developed by connecting the upregulation by d-lactate to a green fluorescent readout. About ~6.0-fold induction by 100 mM d-lactate was observed compared to l-lactate.
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Affiliation(s)
- Kalpana Singh
- School of Energy and Chemical Engineering, UNIST, Ulsan, 44919, Republic of Korea
| | - Satish Kumar Ainala
- School of Energy and Chemical Engineering, UNIST, Ulsan, 44919, Republic of Korea
| | - Yeonhee Kim
- School of Energy and Chemical Engineering, UNIST, Ulsan, 44919, Republic of Korea
- School of Chemical and Biomolecular Engineering, Pusan National University, Busan, 46241, Republic of Korea
| | - Sunghoon Park
- School of Energy and Chemical Engineering, UNIST, Ulsan, 44919, Republic of Korea
- School of Chemical and Biomolecular Engineering, Pusan National University, Busan, 46241, Republic of Korea
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14
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Rajeev L, Luning EG, Zane GM, Juba TR, Kazakov AE, Novichkov PS, Wall JD, Mukhopadhyay A. LurR is a regulator of the central lactate oxidation pathway in sulfate-reducing Desulfovibrio species. PLoS One 2019; 14:e0214960. [PMID: 30964892 PMCID: PMC6456213 DOI: 10.1371/journal.pone.0214960] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 03/22/2019] [Indexed: 11/18/2022] Open
Abstract
The central carbon/lactate utilization pathway in the model sulfate-reducing bacterium, Desulfovibrio vulgaris Hildenborough, is encoded by the highly conserved operon DVU3025-3033. Our earlier in vitro genome-wide study had suggested a network of four two-component system regulators that target this large operon; however, how these four regulators control this operon was not known. Here, we probe the regulation of the lactate utilization operon with mutant strains and DNA-protein binding assays. We show that the LurR response regulator is required for optimal growth and complete lactate utilization, and that it activates the DVU3025-3033 lactate oxidation operon as well as DVU2451, a lactate permease gene, in the presence of lactate. We show by electrophoretic mobility shift assays that LurR binds to three sites in the upstream region of DVU3025, the first gene of the operon. NrfR, a response regulator that is activated under nitrite stress, and LurR share similar binding site motifs and bind the same sites upstream of DVU3025. The DVU3025 promoter also has a binding site motif (Pho box) that is bound by PhoB, a two-component response regulator activated under phosphate limitation. The lactate utilization operon, the regulator LurR, and LurR binding sites are conserved across the order Desulfovibrionales whereas possible modulation of the lactate utilization genes by additional regulators such as NrfR and PhoB appears to be limited to D. vulgaris.
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Affiliation(s)
- Lara Rajeev
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Eric G. Luning
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Grant M. Zane
- Department of Biochemistry, University of Missouri, Columbia, Missouri, United States of America
| | - Thomas R. Juba
- Department of Biochemistry, University of Missouri, Columbia, Missouri, United States of America
| | - Alexey E. Kazakov
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Pavel S. Novichkov
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Judy D. Wall
- Department of Biochemistry, University of Missouri, Columbia, Missouri, United States of America
| | - Aindrila Mukhopadhyay
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- * E-mail:
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15
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Hirose A, Kasai T, Koga R, Suzuki Y, Kouzuma A, Watanabe K. Understanding and engineering electrochemically active bacteria for sustainable biotechnology. BIORESOUR BIOPROCESS 2019. [DOI: 10.1186/s40643-019-0245-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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16
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Lienemann M, TerAvest MA, Pitkänen J, Stuns I, Penttilä M, Ajo‐Franklin CM, Jäntti J. Towards patterned bioelectronics: facilitated immobilization of exoelectrogenic Escherichia coli with heterologous pili. Microb Biotechnol 2018; 11:1184-1194. [PMID: 30296001 PMCID: PMC6196383 DOI: 10.1111/1751-7915.13309] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 07/02/2018] [Accepted: 08/07/2018] [Indexed: 12/01/2022] Open
Abstract
Biosensors detect signals using biological sensing components such as redox enzymes and biological cells. Although cellular versatility can be beneficial for different applications, limited stability and efficiency in signal transduction at electrode surfaces represent a challenge. Recent studies have shown that the Mtr electron conduit from Shewanella oneidensis MR-1 can be produced in Escherichia coli to generate an exoelectrogenic model system with well-characterized genetic tools. However, means to specifically immobilize this organism at solid substrates as electroactive biofilms have not been tested previously. Here, we show that mannose-binding Fim pili can be produced in exoelectrogenic E. coli and can be used to selectively attach cells to a mannose-coated material. Importantly, cells expressing fim genes retained current production by the heterologous Mtr electron conduit. Our results demonstrate the versatility of the exoelectrogenic E. coli system and motivate future work that aims to produce patterned biofilms for bioelectronic devices that can respond to various biochemical signals.
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Affiliation(s)
| | - Michaela A. TerAvest
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMIUSA
- The Molecular FoundryLawrence Berkeley National LaboratoryMolecular Biophysics and Integrated Bioimaging DivisionSynthetic Biology InstituteBerkeleyCAUSA
| | - Juha‐Pekka Pitkänen
- VTT Technical Research Centre of Finland LtdEspooFinland
- Current affiliation: Solar Foods LtdHelsinkiFinland
| | - Ingmar Stuns
- VTT Technical Research Centre of Finland LtdEspooFinland
| | - Merja Penttilä
- VTT Technical Research Centre of Finland LtdEspooFinland
| | - Caroline M. Ajo‐Franklin
- The Molecular FoundryLawrence Berkeley National LaboratoryMolecular Biophysics and Integrated Bioimaging DivisionSynthetic Biology InstituteBerkeleyCAUSA
| | - Jussi Jäntti
- VTT Technical Research Centre of Finland LtdEspooFinland
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17
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Beblawy S, Bursac T, Paquete C, Louro R, Clarke TA, Gescher J. Extracellular reduction of solid electron acceptors by Shewanella oneidensis. Mol Microbiol 2018; 109:571-583. [PMID: 29995975 DOI: 10.1111/mmi.14067] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/26/2018] [Indexed: 12/11/2022]
Abstract
Shewanella oneidensis is the best understood model organism for the study of dissimilatory iron reduction. This review focuses on the current state of our knowledge regarding this extracellular respiratory process and highlights its physiologic, regulatory and biochemical requirements. It seems that we have widely understood how respiratory electrons can reach the cell surface and what the minimal set of electron transport proteins to the cell surface is. Nevertheless, even after decades of work in different research groups around the globe there are still several important questions that were not answered yet. In particular, the physiology of this organism, the possible evolutionary benefit of some responses to anoxic conditions, as well as the exact mechanism of electron transfer onto solid electron acceptors are yet to be addressed. The elucidation of these questions will be a great challenge for future work and important for the application of extracellular respiration in biotechnological processes.
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Affiliation(s)
- Sebastian Beblawy
- Department of Applied Biology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (CS), Karlsruhe, Germany
| | - Thea Bursac
- Department of Applied Biology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (CS), Karlsruhe, Germany
| | - Catarina Paquete
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Av. da República-EAN, Oeiras, 2780-157, Portugal
| | - Ricardo Louro
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Av. da República-EAN, Oeiras, 2780-157, Portugal
| | - Thomas A Clarke
- Centre for Molecular and Structural Biochemistry, School of Biological Sciences and School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Johannes Gescher
- Department of Applied Biology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (CS), Karlsruhe, Germany.,Institute for Biological Interfaces, Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany
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18
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Shewanella oneidensis MR-1 Utilizes both Sodium- and Proton-Pumping NADH Dehydrogenases during Aerobic Growth. Appl Environ Microbiol 2018; 84:AEM.00415-18. [PMID: 29654176 PMCID: PMC5981069 DOI: 10.1128/aem.00415-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 04/05/2018] [Indexed: 02/02/2023] Open
Abstract
Shewanella oneidensis MR-1 is a metal-reducing bacterium with the ability to utilize many different terminal electron acceptors, including oxygen and solid-metal oxides. Both metal oxide reduction and aerobic respiration have been studied extensively in this organism. However, electron transport chain processes upstream of the terminal oxidoreductases have been relatively understudied in this organism, especially electron transfer from NADH to respiratory quinones. Genome annotation indicates that S. oneidensis MR-1 encodes four NADH dehydrogenases, a proton-translocating dehydrogenase (Nuo), two sodium ion-translocating dehydrogenases (Nqr1 and Nqr2), and an “uncoupling” dehydrogenase (Ndh), but none of these complexes have been studied. Therefore, we conducted a study specifically focused on the effects of individual NADH dehydrogenase knockouts in S. oneidensis MR-1. We observed that two of the single-mutant strains, the ΔnuoN and ΔnqrF1 mutants, exhibited significant growth defects compared with the wild type. However, the defects were minor and only apparent under certain growth conditions. Further testing of the ΔnuoN ΔnqrF1 double-mutant strain yielded no growth in minimal medium under oxic conditions, indicating that Nuo and Nqr1 have overlapping functions, but at least one is necessary for aerobic growth. Coutilization of proton- and sodium ion-dependent energetics has important implications for the growth of this organism in environments with varied pH and salinity, including microbial electrochemical systems. IMPORTANCE Bacteria utilize a wide variety of metabolic pathways that allow them to take advantage of different energy sources, and to do so with varied efficiency. The efficiency of a metabolic process determines the growth yield of an organism, or the amount of biomass it produces per amount of substrate consumed. This parameter has important implications in biotechnology and wastewater treatment, where low growth yields are often preferred to minimize the production of microbial biomass. In this study, we investigated respiratory pathways containing NADH dehydrogenases with varied efficiency (i.e., the number of ions translocated per NADH oxidized) in the metal-reducing bacterium Shewanella oneidensis MR-1. We observed that two different respiratory pathways are used concurrently, and at least one pathway must be functional for growth under oxic conditions.
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Lee S, Kim DH, Kim KW. The enhancement and inhibition of mercury reduction by natural organic matter in the presence of Shewanella oneidensis MR-1. CHEMOSPHERE 2018; 194:515-522. [PMID: 29241125 DOI: 10.1016/j.chemosphere.2017.12.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 11/29/2017] [Accepted: 12/02/2017] [Indexed: 06/07/2023]
Abstract
Reduction-oxidation (Redox) processes of mercury (Hg) are of significant importance in influencing Hg speciation, bioavailability, and fate in anoxic environments where natural organic matter (NOM) and dissimilatory metal reducing bacteria (DMRB) are widely observed. However, the redox reaction between Hg and NOM, has not yet been studied in the presence of S. oneidensis MR-1 in anoxic environments. We have found that the reduction rate of mercuric mercury [Hg(II)] in the presence of Elliott soil humic acid (ESHA) was 0.02 h-1. It was faster than the rate (0.01 h-1) in the direct microbial Hg(II) reduction, suggesting that ESHA acts as an electron transfer mediator between cells and Hg, which enhances Hg(II) reduction under anoxic conditions. The overall rate of Hg(II) reduction in the presence of ESHA is determined by the rate of electron transfer from S. oneidensis MR-1 to ESHA (rate-limiting step) since the rate of electron transfer from reduced ESHA to Hg(II) was so rapid. In the reaction between S. oneidensis MR-1 and a variety of NOM analogs, the production rate of elemental mercury [Hg (0)] was linearly correlated with the free radical concentrations and aromaticities in reduced NOM analogs. However, at the high ESHA concentrations or cell contents, Hg(II) reduction might be inhibited by thiol functional groups in reduced ESHA and on cells. We suggest that the presence of NOM, cell concentration and NOM source can significantly affect the redox processes of Hg and therefore, have important implications for elucidating Hg redox processes under environmentally relevant complex conditions.
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Affiliation(s)
- Seyong Lee
- Center for Environmental Assessment Monitoring, Korea Environment Institute (KEI), 370 Sicheong-daero, Sejong, 30147, Republic of Korea
| | - Dong-Hun Kim
- Groundwater and Ecohydrology Research Center, Korea Institute of Geoscience and Mineral Resources (KIGAM), Gwahak-ro, Yuseoung-gu, Daejeon, 34132, Republic of Korea
| | - Kyoung-Woong Kim
- School of Earth Sciences & Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea.
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20
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Dong Z, Guo S, Fu H, Gao H. Investigation of a spontaneous mutant reveals novel features of iron uptake in Shewanella oneidensis. Sci Rep 2017; 7:11788. [PMID: 28924168 PMCID: PMC5603553 DOI: 10.1038/s41598-017-11987-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 08/30/2017] [Indexed: 12/03/2022] Open
Abstract
Shewanella oneidensis is among the first and the best studied bacteria capable of respiring minerals as terminal electron acceptors (EAs), including a variety of iron ores. This respiration process relies on a large number of c-type cytochromes, which per se are iron-containing proteins. Thus, iron plays an essential and special role in iron respiration of S. oneidensis, prompting extensive investigations into iron physiology. Despite this, we still know surprisingly little about the components and characteristics of iron transport in this bacterium. Here, we report that TonB-dependent receptor PutA (SO_3033) is specific to the siderophore-mediated iron uptake. Although homologs of PutA are abundant, none of them can function as a replacement. In the absence of PutA, S. oneidensis suffers from an iron shortage, which leads to a severe defect in production of cytochrome c. However, proteins requiring other types of cytochromes, such as b and d, do not appear to be significantly impacted. Intriguingly, lactate, but not other carbon sources that are routinely used to support growth, is able to promote iron uptake when PutA is missing. We further show that the lactate-mediated iron import is independent of lactate permeases. Overall, our results suggest that in S. oneidensis the siderophore-dependent pathway plays a key role in iron uptake when iron is limited, but many alternative routes exist.
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Affiliation(s)
- Ziyang Dong
- Institute of Microbiology and College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Shupan Guo
- Institute of Microbiology and College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Huihui Fu
- Institute of Microbiology and College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Haichun Gao
- Institute of Microbiology and College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
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21
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Dose-Dependent Prebiotic Effect of Lactulose in a Computer-Controlled In Vitro Model of the Human Large Intestine. Nutrients 2017; 9:nu9070767. [PMID: 28718839 PMCID: PMC5537881 DOI: 10.3390/nu9070767] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 07/10/2017] [Accepted: 07/14/2017] [Indexed: 02/08/2023] Open
Abstract
Lactulose, a disaccharide of galactose and fructose, used as a laxative or ammonia-lowering drug and as a functional food ingredient, enhances growth of Bifidobacterium and Lactobacillus at clinically relevant dosages. The prebiotic effect of subclinical dosages of Lactulose, however, remains to be elucidated. This study analyses changes in the microbiota and their metabolites after a 5 days Lactulose treatment using the TIM-2 system, a computer-controlled model of the proximal large intestine representing a complex, high density, metabolically active, anaerobic microbiota of human origin. Subclinical dosages of 2–5 g Lactulose were used. While 2 g Lactulose already increased the short-chain fatty acid levels of the intestinal content, 5 g Lactulose were required daily for 5 days in this study to exert the full beneficial prebiotic effect consisting of higher bacterial counts of Bifidobacterium, Lactobacillus, and Anaerostipes, a rise in acetate, butyrate and lactate, as well as a decrease in branched-chain fatty acids, pH (suggested by an increase in NaOH usage), and ammonia.
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22
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Desguin B, Soumillion P, Hausinger RP, Hols P. Unexpected complexity in the lactate racemization system of lactic acid bacteria. FEMS Microbiol Rev 2017; 41:S71-S83. [DOI: 10.1093/femsre/fux021] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 04/11/2017] [Indexed: 12/30/2022] Open
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23
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Kasai T, Kouzuma A, Watanabe K. CRP Regulates D-Lactate Oxidation in Shewanella oneidensis MR-1. Front Microbiol 2017; 8:869. [PMID: 28559887 PMCID: PMC5432575 DOI: 10.3389/fmicb.2017.00869] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 04/28/2017] [Indexed: 01/11/2023] Open
Abstract
Shewanella oneidensis MR-1 is a heterotrophic facultative anaerobe that respires using various organic and inorganic compounds. This organism has served as a model to study bacterial metabolic and regulatory systems that facilitate their survival in redox-stratified environments. The expression of many anaerobic respiratory genes in MR-1, including those for the reduction of fumarate, dimethyl sulfoxide, and metal oxides, is regulated by cyclic AMP receptor protein (CRP). However, relatively little is known about how this organism regulates the expression of catabolic enzymes catalyzing the oxidation of organic compounds, including lactate. Here, we investigated transcriptional mechanisms for the lldP (SO_1522) and dld (SO_1521) genes, which encode putative lactate permease and D-lactate dehydrogenase, respectively, and demonstrate that CRP regulates their expression in MR-1. We found that a crp-deletion mutant of MR-1 (Δcrp) showed impaired growth on D-lactate. Complementary expression of dld in Δcrp restored the ability to grow on D-lactate, indicating that the deficient growth of Δcrp on D-lactate is attributable to decreased expression of dld. In vivo transcription and in vitro electrophoretic mobility shift assays reveal that CRP positively regulates the expression of the lldP and dld genes by directly binding to an upstream region of lldP. Taken together, these results indicate that CRP is a global transcriptional regulator that coordinately regulates the expression of catabolic and respiratory pathways in MR-1, including D-lactate dehydrogenase and anaerobic terminal reductases.
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Affiliation(s)
- Takuya Kasai
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences,Hachioji, Japan
| | - Atsushi Kouzuma
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences,Hachioji, Japan
| | - Kazuya Watanabe
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences,Hachioji, Japan
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Formate Metabolism in Shewanella oneidensis Generates Proton Motive Force and Prevents Growth without an Electron Acceptor. J Bacteriol 2016; 198:1337-46. [PMID: 26883823 DOI: 10.1128/jb.00927-15] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 02/08/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Shewanella oneidensis strain MR-1 is a facultative anaerobe that thrives in redox-stratified environments due to its ability to utilize a wide array of terminal electron acceptors. Conversely, the electron donors utilized by S. oneidensis are more limited and include products of primary fermentation such as lactate, pyruvate, formate, and hydrogen. Lactate, pyruvate, and hydrogen metabolisms inS. oneidensis have been described previously, but little is known about the role of formate oxidation in the ecophysiology of these bacteria. Formate is produced by S. oneidensis through pyruvate formate lyase during anaerobic growth on carbon sources that enter metabolism at or above the level of pyruvate, and the genome contains three gene clusters predicted to encode three complete formate dehydrogenase complexes. To determine the contribution of each complex to formate metabolism, strains lacking one, two, or all three annotated formate dehydrogenase gene clusters were generated and examined for growth rates and yields on a variety of carbon sources. Here, we report that formate oxidation contributes to both the growth rate and yield of S. oneidensis through the generation of proton motive force. Exogenous formate also greatly accelerated growth on N-acetylglucosamine, a carbon source normally utilized very slowly by S. oneidensis under anaerobic conditions. Surprisingly, deletion of all three formate dehydrogenase gene clusters enabled growth of S. oneidensis using pyruvate in the absence of a terminal electron acceptor, a mode of growth never before observed in these bacteria. Our results demonstrate that formate oxidation is a fundamental strategy under anaerobic conditions for energy conservation inS. oneidensis. IMPORTANCE Shewanella species have garnered interest in biotechnology applications for their ability to respire extracellular terminal electron acceptors, such as insoluble iron oxides and electrodes. While much effort has gone into studying the proteins for extracellular electron transport, how electrons generated through the oxidation of organic carbon sources enter this pathway remains understudied. Here, we quantify the role of formate oxidation in the anaerobic physiology of Shewanella oneidensis Formate oxidation contributes to both the growth rate and yield on a variety of carbon sources through the generation of proton motive force. Advances in our understanding of the anaerobic metabolism of S. oneidensis are important for our ability to utilize and engineer this organism for applications in bioenergy, biocatalysis, and bioremediation.
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Metabolic Characteristics of a Glucose-Utilizing Shewanella oneidensis Strain Grown under Electrode-Respiring Conditions. PLoS One 2015; 10:e0138813. [PMID: 26394222 PMCID: PMC4579138 DOI: 10.1371/journal.pone.0138813] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 09/03/2015] [Indexed: 12/18/2022] Open
Abstract
In bioelectrochemical systems, the electrode potential is an important parameter affecting the electron flow between electrodes and microbes and microbial metabolic activities. Here, we investigated the metabolic characteristics of a glucose-utilizing strain of engineered Shewanella oneidensis under electrode-respiring conditions in electrochemical reactors for gaining insight into how metabolic pathways in electrochemically active bacteria are affected by the electrode potential. When an electrochemical reactor was operated with its working electrode poised at +0.4 V (vs. an Ag/AgCl reference electrode), the engineered S. oneidensis strain, carrying a plasmid encoding a sugar permease and glucose kinase of Escherichia coli, generated current by oxidizing glucose to acetate and produced D-lactate as an intermediate metabolite. However, D-lactate accumulation was not observed when the engineered strain was grown with a working electrode poised at 0 V. We also found that transcription of genes involved in pyruvate and D-lactate metabolisms was upregulated at a high electrode potential compared with their transcription at a low electrode potential. These results suggest that the carbon catabolic pathway of S. oneidensis can be modified by controlling the potential of a working electrode in an electrochemical bioreactor.
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26
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Kouzuma A, Kasai T, Hirose A, Watanabe K. Catabolic and regulatory systems in Shewanella oneidensis MR-1 involved in electricity generation in microbial fuel cells. Front Microbiol 2015; 6:609. [PMID: 26136738 PMCID: PMC4468914 DOI: 10.3389/fmicb.2015.00609] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 06/02/2015] [Indexed: 12/12/2022] Open
Abstract
Shewanella oneidensis MR-1 is a facultative anaerobe that respires using a variety of inorganic and organic compounds. MR-1 is also capable of utilizing extracellular solid materials, including anodes in microbial fuel cells (MFCs), as electron acceptors, thereby enabling electricity generation. As MFCs have the potential to generate electricity from biomass waste and wastewater, MR-1 has been extensively studied to identify the molecular systems that are involved in electricity generation in MFCs. These studies have demonstrated the importance of extracellular electron-transfer (EET) pathways that electrically connect the quinone pool in the cytoplasmic membrane to extracellular electron acceptors. Electricity generation is also dependent on intracellular catabolic pathways that oxidize electron donors, such as lactate, and regulatory systems that control the expression of genes encoding the components of catabolic and electron-transfer pathways. In addition, recent findings suggest that cell-surface polymers, e.g., exopolysaccharides, and secreted chemicals, which function as electron shuttles, are also involved in electricity generation. Despite these advances in our knowledge on the EET processes in MR-1, further efforts are necessary to fully understand the underlying intra- and extracellular molecular systems for electricity generation in MFCs. We suggest that investigating how MR-1 coordinates these systems to efficiently transfer electrons to electrodes and conserve electrochemical energy for cell proliferation is important for establishing the biological basis for MFCs.
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Affiliation(s)
- Atsushi Kouzuma
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences , Hachioji, Japan
| | - Takuya Kasai
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences , Hachioji, Japan
| | - Atsumi Hirose
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences , Hachioji, Japan
| | - Kazuya Watanabe
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences , Hachioji, Japan
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27
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Enantioselective regulation of lactate racemization by LarR in Lactobacillus plantarum. J Bacteriol 2014; 197:219-30. [PMID: 25349156 DOI: 10.1128/jb.02192-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Lactobacillus plantarum is a lactic acid bacterium that produces a racemic mixture of l- and d-lactate from sugar fermentation. The interconversion of lactate isomers is performed by a lactate racemase (Lar) that is transcriptionally controlled by the l-/d-lactate ratio and maximally induced in the presence of l-lactate. We previously reported that the Lar activity depends on the expression of two divergently oriented operons: (i) the larABCDE operon encodes the nickel-dependent lactate racemase (LarA), its maturases (LarBCE), and a lactic acid channel (LarD), and (ii) the larR(MN)QO operon encodes a transcriptional regulator (LarR) and a four-component ABC-type nickel transporter [Lar(MN), in which the M and N components are fused, LarQ, and LarO]. LarR is a novel regulator of the Crp-Fnr family (PrfA group). Here, the role of LarR was further characterized in vivo and in vitro. We show that LarR is a positive regulator that is absolutely required for the expression of Lar activity. Using gel retardation experiments, we demonstrate that LarR binds to a 16-bp palindromic sequence (Lar box motif) that is present in the larR-larA intergenic region. Mutations in the Lar box strongly affect LarR binding and completely abolish transcription from the larA promoter (PlarA). Two half-Lar boxes located between the Lar box and the -35 box of PlarA promote LarR multimerization on DNA, and point mutations within one or both half-Lar boxes inhibit PlarA induction by l-lactate. Gel retardation and footprinting experiments indicate that l-lactate has a positive effect on the binding and multimerization of LarR, while d-lactate antagonizes the positive effect of l-lactate. A possible mechanism of LarR regulation by lactate enantiomers is proposed.
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Iwatani S, Nagashima H, Reddy R, Shiota S, Graham DY, Yamaoka Y. Identification of the genes that contribute to lactate utilization in Helicobacter pylori. PLoS One 2014; 9:e103506. [PMID: 25078575 PMCID: PMC4117512 DOI: 10.1371/journal.pone.0103506] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 06/30/2014] [Indexed: 02/07/2023] Open
Abstract
Helicobacter pylori are Gram-negative, spiral-shaped microaerophilic bacteria etiologically related to gastric cancer. Lactate utilization has been implicated although no corresponding genes have been identified in the H. pylori genome. Here, we report that gene products of hp0137–0139 (lldEFG), hp0140–0141 (lctP), and hp1222 (dld) contribute to D- and L-lactate utilization in H. pylori. The three-gene unit hp0137–0139 in H. pylori 26695 encodes L-lactate dehydrogenase (LDH) that catalyzes the conversion of lactate to pyruvate in an NAD-dependent manner. Isogenic mutants of these genes were unable to grow on L-lactate-dependent medium. The hp1222 gene product functions as an NAD-independent D-LDH and also contributes to the oxidation of L-lactate; the isogenic mutant of this gene failed to grow on D-lactate-dependent medium. The parallel genes hp0140–0141 encode two nearly identical lactate permeases (LctP) that promote uptake of both D- and L-lactate. Interestingly an alternate route must also exist for lactate transport as the knockout of genes did not completely prevent growth on D- or L-lactate. Gene expression levels of hp0137–0139 and hp1222 were not enhanced by lactate as the carbon source. Expression of hp0140–0141 was slightly suppressed in the presence of L-lactate but not D-lactate. This study identified the genes contributing to the lactate utilization and demonstrated the ability of H. pylori to utilize both D- and L-lactate.
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Affiliation(s)
- Shun Iwatani
- Department of Medicine-Gastroenterology, Baylor College of Medicine and Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas, United States of America
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Oita, Japan
| | - Hiroyuki Nagashima
- Department of Medicine-Gastroenterology, Baylor College of Medicine and Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas, United States of America
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Oita, Japan
| | - Rita Reddy
- Department of Medicine-Gastroenterology, Baylor College of Medicine and Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas, United States of America
| | - Seiji Shiota
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Oita, Japan
| | - David Y. Graham
- Department of Medicine-Gastroenterology, Baylor College of Medicine and Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas, United States of America
| | - Yoshio Yamaoka
- Department of Medicine-Gastroenterology, Baylor College of Medicine and Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas, United States of America
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Oita, Japan
- * E-mail:
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Jiang T, Gao C, Ma C, Xu P. Microbial lactate utilization: enzymes, pathogenesis, and regulation. Trends Microbiol 2014; 22:589-99. [PMID: 24950803 DOI: 10.1016/j.tim.2014.05.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Revised: 05/21/2014] [Accepted: 05/23/2014] [Indexed: 11/17/2022]
Abstract
Lactate utilization endows microbes with the ability to use lactate as a carbon source. Lactate oxidizing enzymes play key roles in the lactate utilization pathway. Various types of these enzymes have been characterized, but novel ones remain to be identified. Lactate determination techniques and biocatalysts have been developed based on these enzymes. Lactate utilization has also been found to induce pathogenicity of several microbes, and the mechanisms have been investigated. More recently, studies on the structure and organization of operons of lactate utilization have been carried out. This review focuses on the recent progress and future perspectives in understanding microbial lactate utilization.
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Affiliation(s)
- Tianyi Jiang
- State Key Laboratory of Microbial Metabolism and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China; State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People's Republic of China; School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan 250101, People's Republic of China
| | - Chao Gao
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People's Republic of China
| | - Cuiqing Ma
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, People's Republic of China.
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China.
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