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Lee WH, Yoon CK, Park H, Park GH, Jeong JH, Cha GD, Lee BH, Lee J, Lee CW, Bootharaju MS, Sunwoo SH, Ryu J, Lee C, Cho YJ, Nam TW, Ahn KH, Hyeon T, Seok YJ, Kim DH. Highly Efficient Nitrogen-Fixing Microbial Hydrogel Device for Sustainable Solar Hydrogen Production. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2306092. [PMID: 37739451 DOI: 10.1002/adma.202306092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 09/20/2023] [Indexed: 09/24/2023]
Abstract
Conversion of sunlight and organic carbon substrates to sustainable energy sources through microbial metabolism has great potential for the renewable energy industry. Despite recent progress in microbial photosynthesis, the development of microbial platforms that warrant efficient and scalable fuel production remains in its infancy. Efficient transfer and retrieval of gaseous reactants and products to and from microbes are particular hurdles. Here, inspired by water lily leaves floating on water, a microbial device designed to operate at the air-water interface and facilitate concomitant supply of gaseous reactants, smooth capture of gaseous products, and efficient sunlight delivery is presented. The floatable device carrying Rhodopseudomonas parapalustris, of which nitrogen fixation activity is first determined through this study, exhibits a hydrogen production rate of 104 mmol h-1 m-2 , which is 53 times higher than that of a conventional device placed at a depth of 2 cm in the medium. Furthermore, a scaled-up device with an area of 144 cm2 generates hydrogen at a high rate of 1.52 L h-1 m-2 . Efficient nitrogen fixation and hydrogen generation, low fabrication cost, and mechanical durability corroborate the potential of the floatable microbial device toward practical and sustainable solar energy conversion.
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Affiliation(s)
- Wang Hee Lee
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
| | - Chang-Kyu Yoon
- School of Biological Sciences and Institute of Microbiology, Seoul National University, Seoul, 08826, Republic of Korea
- Research Institute of Basic Science, Seoul National University, Seoul, 08826, Republic of Korea
| | - Hyunseo Park
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
| | - Ga-Hee Park
- School of Biological Sciences and Institute of Microbiology, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jae Hwan Jeong
- Department of Chemical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Gi Doo Cha
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
| | - Byoung-Hoon Lee
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
| | - Juri Lee
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
| | - Chan Woo Lee
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
| | - Megalamane S Bootharaju
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sung-Hyuk Sunwoo
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jaeyune Ryu
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
| | - Changha Lee
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
| | - Yong-Joon Cho
- Department of Molecular Bioscience, College of Biomedical Science, Kangwon National University, Chuncheon, Gangwon, 24341, Republic of Korea
- Multidimensional Genomics Research Center, Kangwon National University, Chuncheon, Gangwon, 24341, Republic of Korea
| | - Tae-Wook Nam
- School of Biological Sciences and Institute of Microbiology, Seoul National University, Seoul, 08826, Republic of Korea
- MightyBugs, Inc., Busan, 46918, Republic of Korea
| | - Kyung Hyun Ahn
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
| | - Taeghwan Hyeon
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
| | - Yeong-Jae Seok
- School of Biological Sciences and Institute of Microbiology, Seoul National University, Seoul, 08826, Republic of Korea
| | - Dae-Hyeong Kim
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
- Department of Materials Science and Engineering, Seoul National University, Seoul, 08826, Republic of Korea
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2
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Serdyuk OP, Abdullatypov AV, Smolygina LD, Ashikhmin AA, Bolshakov MA. Simultaneous functioning of different light-harvesting complexes-a strategy of adaptation of purple bacterium Rhodopseudomonas palustris to low illumination conditions. PeerJ 2023; 11:e14769. [PMID: 36743963 PMCID: PMC9897067 DOI: 10.7717/peerj.14769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 12/29/2022] [Indexed: 02/03/2023] Open
Abstract
Novel peripheral light-harvesting (LH) complex designated as LL LH2 was isolated along with LH4 complex from Rhodopseudomonas palustris cells grown under low light intensity (LL). FPLC-MS/MS allowed to reveal PucABd and PucBabc apoproteins in LL LH2 complex, which is different from previously described LH4 complex containing PucABd, PucABa and PucBb. The main carotenoids in LL LH2 complex were rhodopin and 3,4-didehydrorhodopin. Three-dimensional modeling demonstrated which amino acid residues of all the β-subunits could interact with carotenoids (Car) and bacteriochlorophyll a (BChl a). Analysis of amino acid sequences of α-subunits of both LL complexes showed presence of different C-terminal motifs, IESSVNVG in αa subunit and IESSIKAV in αd subunit, in the same positions of C-termini, which could reflect different retention force of LL LH2 and LH4 on hydroxyl apatite, facilitating successful isolation of these complexes. Differences of these LL complexes in protein and carotenoid composition, in efficiency of energy transfer from Car to BChl a, which is two times lower in LL LH2 than in LH4, allow to assign it to a novel type of light-harvesting complex in Rhodopseudomonas palustris.
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Affiliation(s)
- Olga Petrovna Serdyuk
- Institute of Basic Biological Problems of the Russian Academy of Sciences—A Separate Subdivision of PSCBR RAS (IBBP RAS), Pushchino, Moscow Region, Russian Federation
| | - Azat Vadimovich Abdullatypov
- Institute of Basic Biological Problems of the Russian Academy of Sciences—A Separate Subdivision of PSCBR RAS (IBBP RAS), Pushchino, Moscow Region, Russian Federation
| | - Lidiya Dmitrievna Smolygina
- Institute of Basic Biological Problems of the Russian Academy of Sciences—A Separate Subdivision of PSCBR RAS (IBBP RAS), Pushchino, Moscow Region, Russian Federation
| | - Aleksandr Aleksandrovich Ashikhmin
- Institute of Basic Biological Problems of the Russian Academy of Sciences—A Separate Subdivision of PSCBR RAS (IBBP RAS), Pushchino, Moscow Region, Russian Federation
| | - Maxim Alexandrovich Bolshakov
- Institute of Basic Biological Problems of the Russian Academy of Sciences—A Separate Subdivision of PSCBR RAS (IBBP RAS), Pushchino, Moscow Region, Russian Federation
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du Toit JP, Lea-Smith DJ, Git A, Hervey JRD, Howe CJ, Pott RWM. Expression of Alternative Nitrogenases in Rhodopseudomonas palustris Is Enhanced Using an Optimized Genetic Toolset for Rapid, Markerless Modifications. ACS Synth Biol 2021; 10:2167-2178. [PMID: 34431288 DOI: 10.1021/acssynbio.0c00496] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The phototrophic bacterium Rhodopseudomonas palustris is emerging as a promising biotechnological chassis organism, due to its resilience to a range of harsh conditions, a wide metabolic repertoire, and the ability to quickly regenerate ATP using light. However, realization of this promise is impeded by a lack of efficient, rapid methods for genetic modification. Here, we present optimized tools for generating chromosomal insertions and deletions employing electroporation as a means of transformation. Generation of markerless strains can be completed in 12 days, approximately half the time for previous conjugation-based methods. This system was used for overexpression of alternative nitrogenase isozymes with the aim of improving biohydrogen productivity. Insertion of the pucBa promoter upstream of vnf and anf nitrogenase operons drove robust overexpression up to 4000-fold higher than wild-type. Transcript quantification was facilitated by an optimized high-quality RNA extraction protocol employing lysis using detergent and heat. Overexpression resulted in increased nitrogenase protein levels, extending to superior hydrogen productivity in bioreactor studies under nongrowing conditions, where promoter-modified strains better utilized the favorable energy state created by reduced competition from cell division. Robust heterologous expression driven by the pucBa promoter is thus attractive for energy-intensive biosyntheses suited to the capabilities of R. palustris. Development of this genetic modification toolset will accelerate the advancement of R. palustris as a biotechnological chassis organism, and insights into the effects of nitrogenase overexpression will guide future efforts in engineering strains for improved hydrogen production.
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Affiliation(s)
- Jan-Pierre du Toit
- Department of Process Engineering, Stellenbosch University, Banghoek Road, Stellenbosch, 7600, South Africa
| | - David J. Lea-Smith
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom
- Department of Biochemistry, University of Cambridge, Hopkins Building, Downing Site, Tennis Court Road, Cambridge, CB2 1QW, United Kingdom
| | - Anna Git
- Department of Biochemistry, University of Cambridge, Hopkins Building, Downing Site, Tennis Court Road, Cambridge, CB2 1QW, United Kingdom
| | - John R. D. Hervey
- Department of Biochemistry, University of Cambridge, Hopkins Building, Downing Site, Tennis Court Road, Cambridge, CB2 1QW, United Kingdom
| | - Christopher J. Howe
- Department of Biochemistry, University of Cambridge, Hopkins Building, Downing Site, Tennis Court Road, Cambridge, CB2 1QW, United Kingdom
| | - Robert W. M. Pott
- Department of Process Engineering, Stellenbosch University, Banghoek Road, Stellenbosch, 7600, South Africa
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Jung JH, Jeong S, Im S, Kim MK, Seo HS, Lim S. Lack of the Bacterial Phytochrome Protein Decreases Deinococcus radiodurans Resistance to Mitomycin C. Front Microbiol 2021; 12:659233. [PMID: 34394020 PMCID: PMC8363230 DOI: 10.3389/fmicb.2021.659233] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 07/12/2021] [Indexed: 11/13/2022] Open
Abstract
Deinococcus radiodurans known for its extraordinary resistance to ionizing radiation contains bacterial phytochrome (BphP), a member of the family of red/far-red light-sensing proteins. In this study, we constructed a bphP mutant strain (ΔbphP) to investigate the role of D. radiodurans BphP (DrBphP) in the DNA damage response. When cells were incubated under light and dark conditions following exposure to DNA damaging agents, such as γ- and UV-radiation and mitomycin C (MMC), no significant difference in cell survival was observed between the wild-type D. radiodurans strain (WT) and ΔbphP. However, when continuously exposed to MMC under light conditions, the WT strain notably exhibited increased survival compared to cells grown in the dark. The increased survival was not observed in the ΔbphP strain. These results are indicative of the protective role of light-activated DrBphP in the presence of MMC. Site-directed mutagenesis revealed that the conserved amino acids Cys-24 and His-532 involved in chromophore binding and signal transduction, respectively, were essential for the protective function of DrBphP. Inactivation of the cognate response regulator (RR; DrBphR) of DrBphP increased MMC resistance in the dark. In trans complementation of the bphP bphR double mutant strain (ΔbphPR) with DrBphR decreased MMC resistance. Considering that DrBphP acts as a light-activated phosphatase that dephosphorylates DrBphR, it appears that phosphorylated DrBphR exerts a negative effect on cell survival in the presence of MMC. DrBphP overexpression resulted in an increase in MMC resistance of ΔbphPR, implying that other RRs might be involved in the DrBphP-mediated signaling pathway. A mutant lacking the dr_0781 gene (Δdr_0781) demonstrated the same MMC phenotype as ΔbphR. Survival was further increased in the bphR dr_0781 double mutant strain compared to each single mutant ΔbphR or Δdr_0781, suggesting that DR_0781 is also involved in the DrBphP-dependent MMC sensitivity. This study uncovered a previously unknown phenomenon of red/far-red light-dependent DNA damage survival mediated by BphP by identifying the conditions under which DrBphP exhibits a fitness advantage.
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Affiliation(s)
- Jong-Hyun Jung
- Radiation Research Division, Korea Atomic Energy Research Institute, Jeongeup, South Korea.,Department of Radiation Science and Technology, University of Science and Technology, Daejeon, South Korea
| | - Soyoung Jeong
- Radiation Research Division, Korea Atomic Energy Research Institute, Jeongeup, South Korea.,Department of Food and Animal Biotechnology, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
| | - Seonghun Im
- Radiation Research Division, Korea Atomic Energy Research Institute, Jeongeup, South Korea
| | - Min-Kyu Kim
- Radiation Research Division, Korea Atomic Energy Research Institute, Jeongeup, South Korea
| | - Ho Seong Seo
- Radiation Research Division, Korea Atomic Energy Research Institute, Jeongeup, South Korea.,Department of Radiation Science and Technology, University of Science and Technology, Daejeon, South Korea
| | - Sangyong Lim
- Radiation Research Division, Korea Atomic Energy Research Institute, Jeongeup, South Korea.,Department of Radiation Science and Technology, University of Science and Technology, Daejeon, South Korea
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Stephens S, Mahadevan R, Allen DG. Engineering Photosynthetic Bioprocesses for Sustainable Chemical Production: A Review. Front Bioeng Biotechnol 2021; 8:610723. [PMID: 33490053 PMCID: PMC7820810 DOI: 10.3389/fbioe.2020.610723] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 12/01/2020] [Indexed: 11/13/2022] Open
Abstract
Microbial production of chemicals using renewable feedstocks such as glucose has emerged as a green alternative to conventional chemical production processes that rely primarily on petroleum-based feedstocks. The carbon footprint of such processes can further be reduced by using engineered cells that harness solar energy to consume feedstocks traditionally considered to be wastes as their carbon sources. Photosynthetic bacteria utilize sophisticated photosystems to capture the energy from photons to generate reduction potential with such rapidity and abundance that cells often cannot use it fast enough and much of it is lost as heat and light. Engineering photosynthetic organisms could enable us to take advantage of this energy surplus by redirecting it toward the synthesis of commercially important products such as biofuels, bioplastics, commodity chemicals, and terpenoids. In this work, we review photosynthetic pathways in aerobic and anaerobic bacteria to better understand how these organisms have naturally evolved to harness solar energy. We also discuss more recent attempts at engineering both the photosystems and downstream reactions that transfer reducing power to improve target chemical production. Further, we discuss different methods for the optimization of photosynthetic bioprocess including the immobilization of cells and the optimization of light delivery. We anticipate this review will serve as an important resource for future efforts to engineer and harness photosynthetic bacteria for chemical production.
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Affiliation(s)
- Sheida Stephens
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada
| | - Radhakrishnan Mahadevan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada.,Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - D Grant Allen
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada
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6
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Swainsbury DJK, Qian P, Jackson PJ, Faries KM, Niedzwiedzki DM, Martin EC, Farmer DA, Malone LA, Thompson RF, Ranson NA, Canniffe DP, Dickman MJ, Holten D, Kirmaier C, Hitchcock A, Hunter CN. Structures of Rhodopseudomonas palustris RC-LH1 complexes with open or closed quinone channels. SCIENCE ADVANCES 2021; 7:7/3/eabe2631. [PMID: 33523887 PMCID: PMC7806223 DOI: 10.1126/sciadv.abe2631] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 11/18/2020] [Indexed: 05/23/2023]
Abstract
The reaction-center light-harvesting complex 1 (RC-LH1) is the core photosynthetic component in purple phototrophic bacteria. We present two cryo-electron microscopy structures of RC-LH1 complexes from Rhodopseudomonas palustris A 2.65-Å resolution structure of the RC-LH114-W complex consists of an open 14-subunit LH1 ring surrounding the RC interrupted by protein-W, whereas the complex without protein-W at 2.80-Å resolution comprises an RC completely encircled by a closed, 16-subunit LH1 ring. Comparison of these structures provides insights into quinone dynamics within RC-LH1 complexes, including a previously unidentified conformational change upon quinone binding at the RC QB site, and the locations of accessory quinone binding sites that aid their delivery to the RC. The structurally unique protein-W prevents LH1 ring closure, creating a channel for accelerated quinone/quinol exchange.
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Affiliation(s)
- David J K Swainsbury
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK.
| | - Pu Qian
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG Eindhoven, Netherlands
| | - Philip J Jackson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, S1 3JD, UK
| | - Kaitlyn M Faries
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Dariusz M Niedzwiedzki
- Center for Solar Energy and Energy Storage, Washington University in St. Louis, St. Louis, MO 63130, USA
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Elizabeth C Martin
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - David A Farmer
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Lorna A Malone
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Rebecca F Thompson
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Neil A Ranson
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Daniel P Canniffe
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Mark J Dickman
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, S1 3JD, UK
| | - Dewey Holten
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Christine Kirmaier
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Andrew Hitchcock
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK.
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7
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Luxem KE, Kraepiel AML, Zhang L, Waldbauer JR, Zhang X. Carbon substrate re-orders relative growth of a bacterium using Mo-, V-, or Fe-nitrogenase for nitrogen fixation. Environ Microbiol 2020; 22:1397-1408. [PMID: 32090445 PMCID: PMC7187303 DOI: 10.1111/1462-2920.14955] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 02/07/2020] [Indexed: 01/21/2023]
Abstract
Biological nitrogen fixation is catalyzed by the molybdenum (Mo), vanadium (V) and iron (Fe)‐only nitrogenase metalloenzymes. Studies with purified enzymes have found that the ‘alternative’ V‐ and Fe‐nitrogenases generally reduce N2 more slowly and produce more byproduct H2 than the Mo‐nitrogenase, leading to an assumption that their usage results in slower growth. Here we show that, in the metabolically versatile photoheterotroph Rhodopseudomonas palustris, the type of carbon substrate influences the relative rates of diazotrophic growth based on different nitrogenase isoforms. The V‐nitrogenase supports growth as fast as the Mo‐nitrogenase on acetate but not on the more oxidized substrate succinate. Our data suggest that this is due to insufficient electron flux to the V‐nitrogenase isoform on succinate compared with acetate. Despite slightly faster growth based on the V‐nitrogenase on acetate, the wild‐type strain uses exclusively the Mo‐nitrogenase on both carbon substrates. Notably, the differences in H2:N2 stoichiometry by alternative nitrogenases (~1.5 for V‐nitrogenase, ~4–7 for Fe‐nitrogenase) and Mo‐nitrogenase (~1) measured here are lower than prior in vitro estimates. These results indicate that the metabolic costs of V‐based nitrogen fixation could be less significant for growth than previously assumed, helping explain why alternative nitrogenase genes persist in diverse diazotroph lineages and are broadly distributed in the environment.
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Affiliation(s)
- Katja E Luxem
- Department of Geosciences, Princeton University, Princeton, NJ, 08544, USA
| | - Anne M L Kraepiel
- Princeton Environmental Institute, Princeton University, Princeton, NJ, 08544, USA
| | - Lichun Zhang
- Department of the Geophysical Sciences, University of Chicago, Chicago, IL, 60637, USA
| | - Jacob R Waldbauer
- Department of the Geophysical Sciences, University of Chicago, Chicago, IL, 60637, USA
| | - Xinning Zhang
- Department of Geosciences, Princeton University, Princeton, NJ, 08544, USA.,Princeton Environmental Institute, Princeton University, Princeton, NJ, 08544, USA
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