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Alavi G, Engelbrecht V, Hemschemeier A, Happe T. The Alga Uronema belkae Has Two Structural Types of [FeFe]-Hydrogenases with Different Biochemical Properties. Int J Mol Sci 2023; 24:17311. [PMID: 38139142 PMCID: PMC10744039 DOI: 10.3390/ijms242417311] [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: 11/03/2023] [Revised: 11/30/2023] [Accepted: 12/07/2023] [Indexed: 12/24/2023] Open
Abstract
Several species of microalgae can convert light energy into molecular hydrogen (H2) by employing enzymes of early phylogenetic origin, [FeFe]-hydrogenases, coupled to the photosynthetic electron transport chain. Bacterial [FeFe]-hydrogenases consist of a conserved domain that harbors the active site cofactor, the H-domain, and an additional domain that binds electron-conducting FeS clusters, the F-domain. In contrast, most algal hydrogenases characterized so far have a structurally reduced, so-termed M1-type architecture, which consists only of the H-domain that interacts directly with photosynthetic ferredoxin PetF as an electron donor. To date, only a few algal species are known to contain bacterial-type [FeFe]-hydrogenases, and no M1-type enzymes have been identified in these species. Here, we show that the chlorophycean alga Uronema belkae possesses both bacterial-type and algal-type [FeFe]-hydrogenases. Both hydrogenase genes are transcribed, and the cells produce H2 under hypoxic conditions. The biochemical analyses show that the two enzymes show features typical for each of the two [FeFe]-hydrogenase types. Most notable in the physiological context is that the bacterial-type hydrogenase does not interact with PetF proteins, suggesting that the two enzymes are integrated differently into the alga's metabolism.
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Affiliation(s)
| | | | - Anja Hemschemeier
- Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr University Bochum, 44801 Bochum, Germany; (G.A.); (V.E.)
| | - Thomas Happe
- Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr University Bochum, 44801 Bochum, Germany; (G.A.); (V.E.)
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2
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Schumann C, Fernández Méndez J, Berggren G, Lindblad P. Novel concepts and engineering strategies for heterologous expression of efficient hydrogenases in photosynthetic microorganisms. Front Microbiol 2023; 14:1179607. [PMID: 37502399 PMCID: PMC10369191 DOI: 10.3389/fmicb.2023.1179607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Accepted: 06/09/2023] [Indexed: 07/29/2023] Open
Abstract
Hydrogen is considered one of the key enablers of the transition towards a sustainable and net-zero carbon economy. When produced from renewable sources, hydrogen can be used as a clean and carbon-free energy carrier, as well as improve the sustainability of a wide range of industrial processes. Photobiological hydrogen production is considered one of the most promising technologies, avoiding the need for renewable electricity and rare earth metal elements, the demands for which are greatly increasing due to the current simultaneous electrification and decarbonization goals. Photobiological hydrogen production employs photosynthetic microorganisms to harvest solar energy and split water into molecular oxygen and hydrogen gas, unlocking the long-pursued target of solar energy storage. However, photobiological hydrogen production has to-date been constrained by several limitations. This review aims to discuss the current state-of-the art regarding hydrogenase-driven photobiological hydrogen production. Emphasis is placed on engineering strategies for the expression of improved, non-native, hydrogenases or photosynthesis re-engineering, as well as their combination as one of the most promising pathways to develop viable large-scale hydrogen green cell factories. Herein we provide an overview of the current knowledge and technological gaps curbing the development of photobiological hydrogenase-driven hydrogen production, as well as summarizing the recent advances and future prospects regarding the expression of non-native hydrogenases in cyanobacteria and green algae with an emphasis on [FeFe] hydrogenases.
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Affiliation(s)
- Conrad Schumann
- Molecular Biomimetics, Department of Chemistry - Ångström, Uppsala University, Uppsala, Sweden
| | - Jorge Fernández Méndez
- Microbial Chemistry, Department of Chemistry - Ångström, Uppsala University, Uppsala, Sweden
| | - Gustav Berggren
- Molecular Biomimetics, Department of Chemistry - Ångström, Uppsala University, Uppsala, Sweden
| | - Peter Lindblad
- Microbial Chemistry, Department of Chemistry - Ångström, Uppsala University, Uppsala, Sweden
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3
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Milrad Y, Nagy V, Elman T, Fadeeva M, Tóth SZ, Yacoby I. A PSII photosynthetic control is activated in anoxic cultures of green algae following illumination. Commun Biol 2023; 6:514. [PMID: 37173420 PMCID: PMC10182038 DOI: 10.1038/s42003-023-04890-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 05/01/2023] [Indexed: 05/15/2023] Open
Abstract
Photosynthetic hydrogen production from microalgae is considered to have potential as a renewable energy source. Yet, the process has two main limitations holding it back from scaling up; (i) electron loss to competing processes, mainly carbon fixation and (ii) sensitivity to O2 which diminishes the expression and the activity of the hydrogenase enzyme catalyzing H2 production. Here we report a third, hitherto unknown challenge: We found that under anoxia, a slow-down switch is activated in photosystem II (PSII), diminishing the maximal photosynthetic productivity by three-fold. Using purified PSII and applying in vivo spectroscopic and mass spectrometric techniques on Chlamydomonas reinhardtii cultures, we show that this switch is activated under anoxia, within 10 s of illumination. Furthermore, we show that the recovery to the initial rate takes place following 15 min of dark anoxia, and propose a mechanism in which, modulation in electron transfer at the acceptor site of PSII diminishes its output. Such insights into the mechanism broaden our understanding of anoxic photosynthesis and its regulation in green algae and inspire new strategies to improve bio-energy yields.
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Affiliation(s)
- Yuval Milrad
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel
| | - Valéria Nagy
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - Tamar Elman
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel
| | - Maria Fadeeva
- Department of Biochemistry, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel
| | - Szilvia Z Tóth
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - Iftach Yacoby
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel.
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4
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Redding KE, Appel J, Boehm M, Schuhmann W, Nowaczyk MM, Yacoby I, Gutekunst K. Advances and challenges in photosynthetic hydrogen production. Trends Biotechnol 2022; 40:1313-1325. [PMID: 35581021 DOI: 10.1016/j.tibtech.2022.04.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 04/14/2022] [Accepted: 04/15/2022] [Indexed: 01/21/2023]
Abstract
The vision to replace coal with hydrogen goes back to Jules Verne in 1874. However, sustainable hydrogen production remains challenging. The most elegant approach is to utilize photosynthesis for water splitting and to subsequently save solar energy as hydrogen. Cyanobacteria and green algae are unicellular photosynthetic organisms that contain hydrogenases and thereby possess the enzymatic equipment for photosynthetic hydrogen production. These features of cyanobacteria and algae have inspired artificial and semi-artificial in vitro techniques, that connect photoexcited materials or enzymes with hydrogenases or mimics of these for hydrogen production. These in vitro methods have on their part been models for the fusion of cyanobacterial and algal hydrogenases to photosynthetic photosystem I (PSI) in vivo, which recently succeeded as proofs of principle.
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Affiliation(s)
- Kevin E Redding
- School of Molecular Sciences and Center for Bioenergy & Photosynthesis, Arizona State University, Tempe, AZ, USA
| | - Jens Appel
- Molecular Plant Physiology, Bioenergetics in Photoautotrophs, University Kassel, 34132 Kassel, Germany
| | - Marko Boehm
- Molecular Plant Physiology, Bioenergetics in Photoautotrophs, University Kassel, 34132 Kassel, Germany
| | - Wolfgang Schuhmann
- Analytical Chemistry - Center for Electrochemical Sciences (CES), Faculty of Chemistry and Biochemistry, Ruhr-University Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Marc M Nowaczyk
- Plant Biochemistry, Faculty of Biology and Biotechnology, Ruhr-University Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany
| | - Iftach Yacoby
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Ramat Aviv, 69978, Israel
| | - Kirstin Gutekunst
- Molecular Plant Physiology, Bioenergetics in Photoautotrophs, University Kassel, 34132 Kassel, Germany.
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5
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Ho TTH, Schwier C, Elman T, Fleuter V, Zinzius K, Scholz M, Yacoby I, Buchert F, Hippler M. Photosystem I light-harvesting proteins regulate photosynthetic electron transfer and hydrogen production. PLANT PHYSIOLOGY 2022; 189:329-343. [PMID: 35157085 PMCID: PMC9070821 DOI: 10.1093/plphys/kiac055] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 01/23/2022] [Indexed: 05/06/2023]
Abstract
Linear electron flow (LEF) and cyclic electron flow (CEF) compete for light-driven electrons transferred from the acceptor side of photosystem I (PSI). Under anoxic conditions, such highly reducing electrons also could be used for hydrogen (H2) production via electron transfer between ferredoxin and hydrogenase in the green alga Chlamydomonas reinhardtii. Partitioning between LEF and CEF is regulated through PROTON-GRADIENT REGULATION5 (PGR5). There is evidence that partitioning of electrons also could be mediated via PSI remodeling processes. This plasticity is linked to the dynamics of PSI-associated light-harvesting proteins (LHCAs) LHCA2 and LHCA9. These two unique light-harvesting proteins are distinct from all other LHCAs because they are loosely bound at the PSAL pole. Here, we investigated photosynthetic electron transfer and H2 production in single, double, and triple mutants deficient in PGR5, LHCA2, and LHCA9. Our data indicate that lhca2 and lhca9 mutants are efficient in photosynthetic electron transfer, that LHCA2 impacts the pgr5 phenotype, and that pgr5/lhca2 is a potent H2 photo-producer. In addition, pgr5/lhca2 and pgr5/lhca9 mutants displayed substantially different H2 photo-production kinetics. This indicates that the absence of LHCA2 or LHCA9 impacts H2 photo-production independently, despite both being attached at the PSAL pole, pointing to distinct regulatory capacities.
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Affiliation(s)
- Thi Thu Hoai Ho
- Institute of Plant Biology and Biotechnology, University of Münster, Münster 48143, Germany
- Faculty of Fisheries, University of Agriculture and Forestry, Hue University, Hue 530000, Vietnam
| | - Chris Schwier
- Institute of Plant Biology and Biotechnology, University of Münster, Münster 48143, Germany
| | - Tamar Elman
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Vera Fleuter
- Institute of Plant Biology and Biotechnology, University of Münster, Münster 48143, Germany
| | - Karen Zinzius
- Institute of Plant Biology and Biotechnology, University of Münster, Münster 48143, Germany
| | - Martin Scholz
- Institute of Plant Biology and Biotechnology, University of Münster, Münster 48143, Germany
| | - Iftach Yacoby
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Felix Buchert
- Institute of Plant Biology and Biotechnology, University of Münster, Münster 48143, Germany
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6
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King SJ, Jerkovic A, Brown LJ, Petroll K, Willows RD. Synthetic biology for improved hydrogen production in Chlamydomonas reinhardtii. Microb Biotechnol 2022; 15:1946-1965. [PMID: 35338590 PMCID: PMC9249334 DOI: 10.1111/1751-7915.14024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 02/09/2022] [Accepted: 02/11/2022] [Indexed: 12/04/2022] Open
Abstract
Hydrogen is a clean alternative to fossil fuels. It has applications for electricity generation and transportation and is used for the manufacturing of ammonia and steel. However, today, H2 is almost exclusively produced from coal and natural gas. As such, methods to produce H2 that do not use fossil fuels need to be developed and adopted. The biological manufacturing of H2 may be one promising solution as this process is clean and renewable. Hydrogen is produced biologically via enzymes called hydrogenases. There are three classes of hydrogenases namely [FeFe], [NiFe] and [Fe] hydrogenases. The [FeFe] hydrogenase HydA1 from the model unicellular algae Chlamydomonas reinhardtii has been studied extensively and belongs to the A1 subclass of [FeFe] hydrogenases that have the highest turnover frequencies amongst hydrogenases (21,000 ± 12,000 H2 s−1 for CaHydA from Clostridium acetobutyliticum). Yet to date, limitations in C. reinhardtii H2 production pathways have hampered commercial scale implementation, in part due to O2 sensitivity of hydrogenases and competing metabolic pathways, resulting in low H2 production efficiency. Here, we describe key processes in the biogenesis of HydA1 and H2 production pathways in C. reinhardtii. We also summarize recent advancements of algal H2 production using synthetic biology and describe valuable tools such as high‐throughput screening (HTS) assays to accelerate the process of engineering algae for commercial biological H2 production.
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Affiliation(s)
- Samuel J King
- Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - Ante Jerkovic
- Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - Louise J Brown
- Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - Kerstin Petroll
- Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - Robert D Willows
- Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia
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7
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Treves H, Küken A, Arrivault S, Ishihara H, Hoppe I, Erban A, Höhne M, Moraes TA, Kopka J, Szymanski J, Nikoloski Z, Stitt M. Carbon flux through photosynthesis and central carbon metabolism show distinct patterns between algae, C 3 and C 4 plants. NATURE PLANTS 2022; 8:78-91. [PMID: 34949804 PMCID: PMC8786664 DOI: 10.1038/s41477-021-01042-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 11/09/2021] [Indexed: 05/26/2023]
Abstract
Photosynthesis-related pathways are regarded as a promising avenue for crop improvement. Whilst empirical studies have shown that photosynthetic efficiency is higher in microalgae than in C3 or C4 crops, the underlying reasons remain unclear. Using a tailor-made microfluidics labelling system to supply 13CO2 at steady state, we investigated in vivo labelling kinetics in intermediates of the Calvin Benson cycle and sugar, starch, organic acid and amino acid synthesis pathways, and in protein and lipids, in Chlamydomonas reinhardtii, Chlorella sorokiniana and Chlorella ohadii, which is the fastest growing green alga on record. We estimated flux patterns in these algae and compared them with published and new data from C3 and C4 plants. Our analyses identify distinct flux patterns supporting faster growth in photosynthetic cells, with some of the algae exhibiting faster ribulose 1,5-bisphosphate regeneration and increased fluxes through the lower glycolysis and anaplerotic pathways towards the tricarboxylic acid cycle, amino acid synthesis and lipid synthesis than in higher plants.
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Affiliation(s)
- Haim Treves
- Max-Planck Institute for Molecular Plant Physiology, Potsdam, Germany.
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel.
| | - Anika Küken
- Max-Planck Institute for Molecular Plant Physiology, Potsdam, Germany
- Bioinformatics group, University of Potsdam, Potsdam, Germany
| | | | - Hirofumi Ishihara
- Max-Planck Institute for Molecular Plant Physiology, Potsdam, Germany
| | - Ines Hoppe
- Bioinformatics group, University of Potsdam, Potsdam, Germany
| | - Alexander Erban
- Max-Planck Institute for Molecular Plant Physiology, Potsdam, Germany
| | - Melanie Höhne
- Max-Planck Institute for Molecular Plant Physiology, Potsdam, Germany
| | - Thiago Alexandre Moraes
- Max-Planck Institute for Molecular Plant Physiology, Potsdam, Germany
- Crop Science Centre, University of Cambridge, Cambridge, UK
| | - Joachim Kopka
- Max-Planck Institute for Molecular Plant Physiology, Potsdam, Germany
| | - Jedrzej Szymanski
- Department of Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, OT Gatersleben, Germany
| | - Zoran Nikoloski
- Max-Planck Institute for Molecular Plant Physiology, Potsdam, Germany
- Bioinformatics group, University of Potsdam, Potsdam, Germany
| | - Mark Stitt
- Max-Planck Institute for Molecular Plant Physiology, Potsdam, Germany
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8
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Kosourov S, Böhm M, Senger M, Berggren G, Stensjö K, Mamedov F, Lindblad P, Allahverdiyeva Y. Photosynthetic hydrogen production: Novel protocols, promising engineering approaches and application of semi-synthetic hydrogenases. PHYSIOLOGIA PLANTARUM 2021; 173:555-567. [PMID: 33860946 DOI: 10.1111/ppl.13428] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 04/05/2021] [Indexed: 06/12/2023]
Abstract
Photosynthetic production of molecular hydrogen (H2 ) by cyanobacteria and green algae is a potential source of renewable energy. These organisms are capable of water biophotolysis by taking advantage of photosynthetic apparatus that links water oxidation at Photosystem II and reduction of protons to H2 downstream of Photosystem I. Although the process has a theoretical potential to displace fossil fuels, photosynthetic H2 production in its current state is not yet efficient enough for industrial applications due to a number of physiological, biochemical, and engineering barriers. This article presents a short overview of the metabolic pathways and enzymes involved in H2 photoproduction in cyanobacteria and green algae and our present understanding of the mechanisms of this process. We also summarize recent advances in engineering photosynthetic cell factories capable of overcoming the major barriers to efficient and sustainable H2 production.
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Affiliation(s)
- Sergey Kosourov
- Molecular Plant Biology, Department of Life Technologies, University of Turku, Turku, Finland
| | - Maximilian Böhm
- Molecular Biomimetics, Department of Chemistry-Ångström, Ångström Laboratory, Uppsala University, Uppsala, Sweden
| | - Moritz Senger
- Molecular Biomimetics, Department of Chemistry-Ångström, Ångström Laboratory, Uppsala University, Uppsala, Sweden
| | - Gustav Berggren
- Molecular Biomimetics, Department of Chemistry-Ångström, Ångström Laboratory, Uppsala University, Uppsala, Sweden
| | - Karin Stensjö
- Microbial Chemistry, Department of Chemistry-Ångström, Ångström Laboratory, Uppsala University, Uppsala, Sweden
| | - Fikret Mamedov
- Molecular Biomimetics, Department of Chemistry-Ångström, Ångström Laboratory, Uppsala University, Uppsala, Sweden
| | - Peter Lindblad
- Microbial Chemistry, Department of Chemistry-Ångström, Ångström Laboratory, Uppsala University, Uppsala, Sweden
| | - Yagut Allahverdiyeva
- Molecular Plant Biology, Department of Life Technologies, University of Turku, Turku, Finland
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9
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Improved photosynthetic capacity and photosystem I oxidation via heterologous metabolism engineering in cyanobacteria. Proc Natl Acad Sci U S A 2021; 118:2021523118. [PMID: 33836593 PMCID: PMC7980454 DOI: 10.1073/pnas.2021523118] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Cyanobacteria have been increasingly explored as a biotechnological platform, although their economic feasibility relies in part on the capacity to maximize their photosynthetic, solar-to-biomass energy conversion efficiency. Here we show that cyanobacterial photosynthetic capacity can be increased by diverting cellular resources toward heterologous, energy-storing metabolic pathways and by reducing electron flow to photoprotective, but energy-dissipating, oxygen reduction reactions. We further show that these heterologous sinks can partially contribute to photosystem I (PSI) oxidation, suggesting an engineering strategy to improve both energy storage capacity and robustness by selective diversion of excess photosynthetic capacity to productive processes. Cyanobacteria must prevent imbalances between absorbed light energy (source) and the metabolic capacity (sink) to utilize it to protect their photosynthetic apparatus against damage. A number of photoprotective mechanisms assist in dissipating excess absorbed energy, including respiratory terminal oxidases and flavodiiron proteins, but inherently reduce photosynthetic efficiency. Recently, it has been hypothesized that some engineered metabolic pathways may improve photosynthetic performance by correcting source/sink imbalances. In the context of this subject, we explored the interconnectivity between endogenous electron valves, and the activation of one or more heterologous metabolic sinks. We coexpressed two heterologous metabolic pathways that have been previously shown to positively impact photosynthetic activity in cyanobacteria, a sucrose production pathway (consuming ATP and reductant) and a reductant-only consuming cytochrome P450. Sucrose export was associated with improved quantum yield of phtotosystem II (PSII) and enhanced electron transport chain flux, especially at lower illumination levels, while cytochrome P450 activity led to photosynthetic enhancements primarily observed under high light. Moreover, coexpression of these two heterologous sinks showed additive impacts on photosynthesis, indicating that neither sink alone was capable of utilizing the full “overcapacity” of the electron transport chain. We find that heterologous sinks may partially compensate for the loss of photosystem I (PSI) oxidizing mechanisms even under rapid illumination changes, although this compensation is incomplete. Our results provide support for the theory that heterologous metabolism can act as a photosynthetic sink and exhibit some overlapping functionality with photoprotective mechanisms, while potentially conserving energy within useful metabolic products that might otherwise be “lost.”
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10
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Nagy V, Podmaniczki A, Vidal-Meireles A, Kuntam S, Herman É, Kovács L, Tóth D, Scoma A, Tóth SZ. Thin cell layer cultures of Chlamydomonas reinhardtii L159I-N230Y, pgrl1 and pgr5 mutants perform enhanced hydrogen production at sunlight intensity. BIORESOURCE TECHNOLOGY 2021; 333:125217. [PMID: 33951580 DOI: 10.1016/j.biortech.2021.125217] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/20/2021] [Accepted: 04/21/2021] [Indexed: 05/27/2023]
Abstract
Photobiological hydrogen (H2) production is a promising renewable energy source. HydA hydrogenases of green algae are efficient but O2-sensitive and compete for electrons with CO2-fixation. Recently, we established a photoautotrophic H2 production system based on anaerobic induction, where the Calvin-Benson cycle is inactive and O2 scavenged by an absorbent. Here, we employed thin layer cultures, resulting in a three-fold increase in H2 production relative to bulk CC-124 cultures (50 µg chlorophyll/ml, 350 µmol photons m-2 s-1). Productivity was maintained when increasing the light intensity to 1000 µmol photons m-2s-1 and the cell density to 150 µg chlorophyll/ml. Remarkably, the L159I-N230Y photosystem II mutant and the pgrl1 photosystem I cyclic electron transport mutant produced 50% more H2 than CC-124, while the pgr5 mutant generated 250% more (1.2 ml H2/ml culture in six days). The photosynthetic apparatus of the pgr5 mutant and its in vitro HydA activity remained remarkably stable.
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Affiliation(s)
- Valéria Nagy
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - Anna Podmaniczki
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári krt. 62, H-6726 Szeged, Hungary; Doctoral School of Biology, University of Szeged, Közép fasor 52, H-6722 Szeged, Hungary
| | - André Vidal-Meireles
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - Soujanya Kuntam
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - Éva Herman
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - László Kovács
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - Dávid Tóth
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári krt. 62, H-6726 Szeged, Hungary; Doctoral School of Biology, University of Szeged, Közép fasor 52, H-6722 Szeged, Hungary
| | - Alberto Scoma
- Engineered Microbial Systems Laboratory (EMS-Lab), Department of Biological and Chemical Engineering, Aarhus University, Hangøvej 2, 8200 Aarhus, Denmark
| | - Szilvia Z Tóth
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári krt. 62, H-6726 Szeged, Hungary.
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11
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Milrad Y, Schweitzer S, Feldman Y, Yacoby I. Bi-directional electron transfer between H2 and NADPH mitigates light fluctuation responses in green algae. PLANT PHYSIOLOGY 2021; 186:168-179. [PMID: 33793951 PMCID: PMC8154092 DOI: 10.1093/plphys/kiab051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 01/21/2021] [Indexed: 05/05/2023]
Abstract
The metabolism of green algae has been the focus of much research over the last century. These photosynthetic organisms can thrive under various conditions and adapt quickly to changing environments by concomitant usage of several metabolic apparatuses. The main electron coordinator in their chloroplasts, nicotinamide adenine dinucleotide phosphate (NADPH), participates in many enzymatic activities and is also responsible for inter-organellar communication. Under anaerobic conditions, green algae also accumulate molecular hydrogen (H2), a promising alternative for fossil fuels. However, to scale-up its accumulation, a firm understanding of its integration in the photosynthetic apparatus is still required. While it is generally accepted that NADPH metabolism correlates to H2 accumulation, the mechanism of this collaboration is still vague and relies on indirect measurements. Here, we investigated this connection in Chlamydomonas reinhardtii using simultaneous measurements of both dissolved gases concentration, NADPH fluorescence and electrochromic shifts at 520-546 nm. Our results indicate that energy transfer between H2 and NADPH is bi-directional and crucial for the maintenance of redox balance under light fluctuations. At light onset, NADPH consumption initially eventuates in H2 evolution, which initiates the photosynthetic electron flow. Later on, as illumination continues the majority of NADPH is diverted to the Calvin-Benson-Bassham cycle. Dark onset triggers re-assimilation of H2, which produces NADPH and so, enables initiation of dark fermentative metabolism.
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Affiliation(s)
- Yuval Milrad
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Shira Schweitzer
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Yael Feldman
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Iftach Yacoby
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
- Author for communication: (I.Y.)
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Nagarajan D, Dong CD, Chen CY, Lee DJ, Chang JS. Biohydrogen production from microalgae-Major bottlenecks and future research perspectives. Biotechnol J 2021; 16:e2000124. [PMID: 33249754 DOI: 10.1002/biot.202000124] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 10/25/2020] [Indexed: 12/11/2022]
Abstract
The imprudent use of fossil fuels has resulted in high greenhouse gas (GHG) emissions, leading to climate change and global warming. Reduction in GHG emissions and energy insecurity imposed by the depleting fossil fuel reserves led to the search for alternative sustainable fuels. Hydrogen is a potential alternative energy carrier and is of particular interest because hydrogen combustion releases only water. Hydrogen is also an important industrial feedstock. As an alternative energy carrier, hydrogen can be used in fuel cells for power generation. Current hydrogen production mainly relies on fossil fuels and is usually energy and CO2 -emission intensive, thus the use of fossil fuel-derived hydrogen as a carbon-free fuel source is fallacious. Biohydrogen production can be achieved via microbial methods, and the use of microalgae for hydrogen production is outstanding due to the carbon mitigating effects and the utilization of solar energy as an energy source by microalgae. This review provides comprehensive information on the mechanisms of hydrogen production by microalgae and the enzymes involved. The major challenges in the commercialization of microalgae-based photobiological hydrogen production are critically analyzed and future research perspectives are discussed. Life cycle analysis and economic assessment of hydrogen production by microalgae are also presented.
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Affiliation(s)
- Dillirani Nagarajan
- Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan.,Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan
| | - Cheng-Di Dong
- Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Nanzih District, Kaohsiung, Taiwan
| | - Chun-Yen Chen
- Center for Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan
| | - Duu-Jong Lee
- Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan
| | - Jo-Shu Chang
- Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan.,Department of Chemical and Materials Engineering, College of Engineering, Tunghai University, Taichung, Taiwan.,Research Center for Smart Sustainable Circular Economy, Tunghai University, Taichung, Taiwan
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Water oxidation by photosystem II is the primary source of electrons for sustained H 2 photoproduction in nutrient-replete green algae. Proc Natl Acad Sci U S A 2020; 117:29629-29636. [PMID: 33168746 PMCID: PMC7703569 DOI: 10.1073/pnas.2009210117] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Photosynthetic H2 production in the green alga Chlamydomonas reinhardtii is catalyzed by O2-sensitive [FeFe]-hydrogenases, which accept electrons from photosynthetically reduced ferredoxin and reduce protons to H2. Since the process occurs downstream of photosystem I, the contribution of photosystem II (PSII) in H2 photoproduction has long been a subject of debate. Indeed, water oxidation by PSII results in O2 accumulation in chloroplasts, which inhibits H2 evolution. Therefore, clear evidence for direct water biophotolysis resulting in simultaneous H2 and O2 releases in algae has never been presented. This paper demonstrates that sustained H2 photoproduction in C. reinhardtii is directly linked to PSII-dependent water oxidation and brings insights into regulation of PSII activity and H2 production by CO2/HCO3– under microoxic conditions. The unicellular green alga Chlamydomonas reinhardtii is capable of photosynthetic H2 production. H2 evolution occurs under anaerobic conditions and is difficult to sustain due to 1) competition between [FeFe]-hydrogenase (H2ase), the key enzyme responsible for H2 metabolism in algae, and the Calvin–Benson–Bassham (CBB) cycle for photosynthetic reductants and 2) inactivation of H2ase by O2 coevolved in photosynthesis. Recently, we achieved sustainable H2 photoproduction by shifting algae from continuous illumination to a train of short (1 s) light pulses, interrupted by longer (9 s) dark periods. This illumination regime prevents activation of the CBB cycle and redirects photosynthetic electrons to H2ase. Employing membrane-inlet mass spectrometry and H218O, we now present clear evidence that efficient H2 photoproduction in pulse-illuminated algae depends primarily on direct water biophotolysis, where water oxidation at the donor side of photosystem II (PSII) provides electrons for the reduction of protons by H2ase downstream of photosystem I. This occurs exclusively in the absence of CO2 fixation, while with the activation of the CBB cycle by longer (8 s) light pulses the H2 photoproduction ceases and instead a slow overall H2 uptake is observed. We also demonstrate that the loss of PSII activity in DCMU-treated algae or in PSII-deficient mutant cells can be partly compensated for by the indirect (PSII-independent) H2 photoproduction pathway, but only for a short (<1 h) period. Thus, PSII activity is indispensable for a sustained process, where it is responsible for more than 92% of the final H2 yield.
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Burlacot A, Li-Beisson Y, Peltier G. Membrane Inlet Mass Spectrometry at the Crossroads of Photosynthesis, Biofuel, and Climate Research. PLANT PHYSIOLOGY 2020; 183:451-454. [PMID: 32317361 PMCID: PMC7271806 DOI: 10.1104/pp.20.00368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 03/26/2020] [Indexed: 05/02/2023]
Abstract
Advances in algal biology have built on gas exchange measurements by MIMS in the fields of photosynthesis, biofuel production, and climate research.
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Affiliation(s)
- Adrien Burlacot
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, Saint Paul-Lez-Durance, France F-13108
| | - Yonghua Li-Beisson
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, Saint Paul-Lez-Durance, France F-13108
| | - Gilles Peltier
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, Saint Paul-Lez-Durance, France F-13108
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15
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Algae-Bacteria Consortia as a Strategy to Enhance H 2 Production. Cells 2020; 9:cells9061353. [PMID: 32486026 PMCID: PMC7348838 DOI: 10.3390/cells9061353] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 05/25/2020] [Accepted: 05/26/2020] [Indexed: 12/11/2022] Open
Abstract
Biological hydrogen production by microalgae is a potential sustainable, renewable and clean source of energy. However, many barriers limiting photohydrogen production in these microorganisms remain unsolved. In order to explore this potential and make biohydrogen industrially affordable, the unicellular microalga Chlamydomonas reinhardtii is used as a model system to solve barriers and identify new approaches that can improve hydrogen production. Recently, Chlamydomonas–bacteria consortia have opened a new window to improve biohydrogen production. In this study, we review the different consortia that have been successfully employed and analyze the factors that could be behind the improved H2 production.
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16
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Wei L, Fan B, Yi J, Xie T, Liu K, Ma W. Mechanistic insights into pH-dependent H 2 photoproduction in bisulfite-treated Chlamydomonas cells. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:64. [PMID: 32280372 PMCID: PMC7132995 DOI: 10.1186/s13068-020-01704-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 03/27/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Bisulfite addition is an important H2 photoproduction strategy that removes O2 and activates hydrogenase. The pH values of cell cultures can change the ratio of bisulfite to sulfite, which may affect H2 photoproduction. However, little is known regarding the pH effect of bisulfite addition on H2 photoproduction and relevant underlying mechanism. RESULTS Here, changes in H2 photoproduction with different initial extracellular pH values showed a parabolic distribution and a pH of 8.0 is an optimal value for H2 photoproduction in Chlamydomonas reinhardtii cells treated with bisulfite. Compared to the growth pH (pH 7.3), increased photoproduction of H2 at this optimal pH was primarily caused by a relatively high residual activity of photosystem II (PSII), which provides a relatively plentiful source of electrons for H2 photoproduction. Such increased H2 photoproduction was most likely a result of decreased the ratio of bisulfite to sulfite, consistent with the result that the toxicity of bisulfite on PSII was much more than that of sulfite. This possibility was corroborated by the result that treatment with a combination of 7 mM bisulfite and 6 mM sulfite further enhanced H2 photoproduction compared with 13 mM bisulfite alone. CONCLUSIONS Collectively, our findings provide novel mechanistic insights into pH-dependent H2 photoproduction in C. reinhardtii cells treated with bisulfite, and demonstrate that sulfite addition is another important strategy for H2 photoproduction, just like bisulfite addition.
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Affiliation(s)
- Lanzhen Wei
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Guilin Road 100, Shanghai, 200234 China
| | - Baoqiang Fan
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Guilin Road 100, Shanghai, 200234 China
| | - Jing Yi
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Guilin Road 100, Shanghai, 200234 China
| | - Tianqun Xie
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Guilin Road 100, Shanghai, 200234 China
| | - Kun Liu
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Guilin Road 100, Shanghai, 200234 China
| | - Weimin Ma
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Guilin Road 100, Shanghai, 200234 China
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17
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Ben-Zvi O, Dafni E, Feldman Y, Yacoby I. Re-routing photosynthetic energy for continuous hydrogen production in vivo. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:266. [PMID: 31737095 PMCID: PMC6844042 DOI: 10.1186/s13068-019-1608-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Accepted: 11/04/2019] [Indexed: 05/09/2023]
Abstract
BACKGROUND Hydrogen is considered a promising energy vector that can be produced from sustainable resources such as sunlight and water. In green algae, such as Chlamydomonas reinhardtii, photoproduction of hydrogen is catalyzed by the enzyme [FeFe]-hydrogenase (HydA). Although highly efficient, this process is transitory and thought to serve as a release valve for excess reducing power. Up to date, prolonged production of hydrogen was achieved by the deprivation of either nutrients or light, thus, hindering the full potential of photosynthetic hydrogen production. Previously we showed that the enzyme superoxide dismutase (SOD) can enhance HydA activity in vitro, specifically when tied together to a fusion protein. RESULTS In this work, we explored the in vivo hydrogen production phenotype of HydA-SOD fusion. We found a sustained hydrogen production, which is dependent on linear electron flow, although other pathways feed it as well. In addition, other characteristics such as slower growth and oxygen production were also observed in Hyd-SOD-expressing algae. CONCLUSIONS The Hyd-SOD fusion manages to outcompete the Calvin-Benson cycle, allowing sustained hydrogen production for up to 14 days in non-limiting conditions.
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Affiliation(s)
- Oren Ben-Zvi
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978 Israel
| | - Eyal Dafni
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978 Israel
| | - Yael Feldman
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978 Israel
| | - Iftach Yacoby
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978 Israel
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19
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Mellor SB, Vinde MH, Nielsen AZ, Hanke GT, Abdiaziz K, Roessler MM, Burow M, Motawia MS, Møller BL, Jensen PE. Defining optimal electron transfer partners for light-driven cytochrome P450 reactions. Metab Eng 2019; 55:33-43. [PMID: 31091467 DOI: 10.1016/j.ymben.2019.05.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 05/02/2019] [Accepted: 05/04/2019] [Indexed: 12/16/2022]
Abstract
Plants and cyanobacteria are promising heterologous hosts for metabolic engineering, and particularly suited for expression of cytochrome P450 (P450s), enzymes that catalyse key steps in biosynthetic pathways leading to valuable natural products such as alkaloids, terpenoids and phenylpropanoids. P450s are often difficult to express and require a membrane-bound NADPH-dependent reductase, complicating their use in metabolic engineering and bio-production. We previously demonstrated targeting of heterologous P450s to thylakoid membranes both in N. benthamiana chloroplasts and cyanobacteria, and functional substitution of their native reductases with the photosynthetic apparatus via the endogenous soluble electron carrier ferredoxin. However, because ferredoxin acts as a sorting hub for photosynthetic reducing power, there is fierce competition for reducing equivalents, which limits photosynthesis-driven P450 output. This study compares the ability of four electron carriers to increase photosynthesis-driven P450 activity. These carriers, three plant ferredoxins and a flavodoxin-like engineered protein derived from cytochrome P450 reductase, show only modest differences in their electron transfer to our model P450, CYP79A1 in vitro. However, only the flavodoxin-like carrier supplies appreciable reducing power in the presence of competition for reduced ferredoxin, because it possesses a redox potential that renders delivery of reducing equivalents to endogenous processes inefficient. We further investigate the efficacy of these electron carrier proteins in vivo by expressing them transiently in N. benthamiana fused to CYP79A1. All but one of the fusion enzymes show improved sequestration of photosynthetic reducing power. Fusion with the flavodoxin-like carrier offers the greatest improvement in this comparison - nearly 25-fold on a per protein basis. Thus, this study demonstrates that synthetic electron transfer pathways with optimal redox potentials can alleviate the problem of endogenous competition for reduced ferredoxin and sets out a new metabolic engineering strategy useful for producing valuable natural products.
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Affiliation(s)
- Silas Busck Mellor
- Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
| | - Marcos Hamborg Vinde
- Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
| | - Agnieszka Zygadlo Nielsen
- Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
| | - Guy Thomas Hanke
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, United Kingdom
| | - Kaltum Abdiaziz
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, United Kingdom
| | - Maxie M Roessler
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, United Kingdom
| | - Meike Burow
- DyNaMo Center of Excellence, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
| | - Mohammed Saddik Motawia
- Villum Research Center for Plant Plasticity, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
| | - Birger Lindberg Møller
- Villum Research Center for Plant Plasticity, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
| | - Poul Erik Jensen
- Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark.
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20
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Biological hydrogen production: molecular and electrolytic perspectives. World J Microbiol Biotechnol 2019; 35:116. [PMID: 31332538 DOI: 10.1007/s11274-019-2692-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 07/07/2019] [Indexed: 10/26/2022]
Abstract
Exploration of renewable energy sources is an imperative task in order to replace fossil fuels and to diminish atmospheric pollution. Hydrogen is considered one of the most promising fuels for the future and implores further investigation to find eco-friendly ways toward viable production. Expansive processes like electrolysis and fossil fuels are currently being used to produce hydrogen. Biological hydrogen production (BHP) displays recyclable and economical traits, and is thus imperative for hydrogen economy. Three basic modes of BHP were investigated, including bio photolysis, photo fermentation and dark fermentation. Photosynthetic microorganisms could readily serve as powerhouses to successively produce this type of energy. Cyanobacteria, blue green algae (bio photolysis) and some purple non-sulfur bacteria (Photo fermentation) utilize solar energy and produce hydrogen during their metabolic processes. Ionic species, including hydrogen (H+) and electrons (e-) are combined into hydrogen gas (H2), with the use of special enzymes called hydrogenases in the case of bio photolysis, and nitrogenases catalyze the formation of hydrogen in the case of photo fermentation. Nevertheless, oxygen sensitivity of these enzymes is a drawback for bio photolysis and photo fermentation, whereas, the amount of hydrogen per unit substrate produced appears insufficient for dark fermentation. This review focuses on innovative advances in the bioprocess research, genetic engineering and bioprocess technologies such as microbial fuel cell technology, in developing bio hydrogen production.
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21
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Tóth SZ, Yacoby I. Paradigm Shift in Algal H 2 Production: Bypassing Competitive Processes. Trends Biotechnol 2019; 37:1159-1163. [PMID: 31174881 DOI: 10.1016/j.tibtech.2019.05.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 04/29/2019] [Accepted: 05/03/2019] [Indexed: 12/26/2022]
Abstract
Hydrogen is a promising energy carrier, but producing it sustainably remains a challenge. Green algae can produce hydrogen photosynthetically using their efficient but oxygen-sensitive hydrogenases. Recent strategies aiming to bypass competing processes provide a promising route for scaling up algal hydrogen production.
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Affiliation(s)
- Szilvia Z Tóth
- Institute of Plant Biology, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Temesvári krt. 62, H-6726 Szeged, Hungary.
| | - Iftach Yacoby
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Ramat Aviv, 69978, Israel.
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Jokel M, Nagy V, Tóth SZ, Kosourov S, Allahverdiyeva Y. Elimination of the flavodiiron electron sink facilitates long-term H 2 photoproduction in green algae. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:280. [PMID: 31827608 PMCID: PMC6894204 DOI: 10.1186/s13068-019-1618-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 11/23/2019] [Indexed: 05/14/2023]
Abstract
BACKGROUND The development of renewable and sustainable biofuels to cover the future energy demand is one of the most challenging issues of our time. Biohydrogen, produced by photosynthetic microorganisms, has the potential to become a green biofuel and energy carrier for the future sustainable world, since it provides energy without CO2 emission. The recent development of two alternative protocols to induce hydrogen photoproduction in green algae enables the function of the O2-sensitive [FeFe]-hydrogenases, located at the acceptor side of photosystem I, to produce H2 for several days. These protocols prevent carbon fixation and redirect electrons toward H2 production. In the present work, we employed these protocols to a knockout Chlamydomonas reinhardtii mutant lacking flavodiiron proteins (FDPs), thus removing another possible electron competitor with H2 production. RESULTS The deletion of the FDP electron sink resulted in the enhancement of H2 photoproduction relative to wild-type C. reinhardtii. Additionally, the lack of FDPs leads to a more effective obstruction of carbon fixation even under elongated light pulses. CONCLUSIONS We demonstrated that the rather simple adjustment of cultivation conditions together with genetic manipulation of alternative electron pathways of photosynthesis results in efficient re-routing of electrons toward H2 photoproduction. Furthermore, the introduction of a short recovery phase by regular switching from H2 photoproduction to biomass accumulation phase allows to maintain cell fitness and use photosynthetic cells as long-term H2-producing biocatalysts.
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Affiliation(s)
- Martina Jokel
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014 Turku, Finland
| | - Valéria Nagy
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014 Turku, Finland
| | - Szilvia Z. Tóth
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári krt. 62, Szeged, 6726 Hungary
| | - Sergey Kosourov
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014 Turku, Finland
| | - Yagut Allahverdiyeva
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014 Turku, Finland
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Burlacot A, Sawyer A, Cuiné S, Auroy-Tarrago P, Blangy S, Happe T, Peltier G. Flavodiiron-Mediated O 2 Photoreduction Links H 2 Production with CO 2 Fixation during the Anaerobic Induction of Photosynthesis. PLANT PHYSIOLOGY 2018; 177:1639-1649. [PMID: 29976836 PMCID: PMC6084654 DOI: 10.1104/pp.18.00721] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 06/25/2018] [Indexed: 05/04/2023]
Abstract
Some microalgae, such as Chlamydomonas reinhardtii, harbor a highly flexible photosynthetic apparatus capable of using different electron acceptors, including carbon dioxide (CO2), protons, or oxygen (O2), allowing survival in diverse habitats. During anaerobic induction of photosynthesis, molecular O2 is produced at photosystem II, while at the photosystem I acceptor side, the reduction of protons into hydrogen (H2) by the plastidial [FeFe]-hydrogenases primes CO2 fixation. Although the interaction between H2 production and CO2 fixation has been studied extensively, their interplay with O2 produced by photosynthesis has not been considered. By simultaneously measuring gas exchange and chlorophyll fluorescence, we identified an O2 photoreduction mechanism that functions during anaerobic dark-to-light transitions and demonstrate that flavodiiron proteins (Flvs) are the major players involved in light-dependent O2 uptake. We further show that Flv-mediated O2 uptake is critical for the rapid induction of CO2 fixation but is not involved in the creation of the micro-oxic niches proposed previously to protect the [FeFe]-hydrogenase from O2 By studying a mutant lacking both hydrogenases (HYDA1 and HYDA2) and both Flvs (FLVA and FLVB), we show that the induction of photosynthesis is strongly delayed in the absence of both sets of proteins. Based on these data, we propose that Flvs are involved in an important intracellular O2 recycling process, which acts as a relay between H2 production and CO2 fixation.
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Affiliation(s)
- Adrien Burlacot
- Laboratoire de Bioénergétique et de Biotechnologie des Microalgues, BIAM, CEA, CNRS, Aix Marseille Univ, F-13108 Saint-Paul-lez-Durance, France
| | - Anne Sawyer
- AG Photobiotechnologie, Lehrstuhl für Biochemie der Pflanzen, Fakultät für Biologie und Biotechnologie, Ruhr-Universität Bochum, 44801 Bochum, Germany
| | - Stéphan Cuiné
- Laboratoire de Bioénergétique et de Biotechnologie des Microalgues, BIAM, CEA, CNRS, Aix Marseille Univ, F-13108 Saint-Paul-lez-Durance, France
| | - Pascaline Auroy-Tarrago
- Laboratoire de Bioénergétique et de Biotechnologie des Microalgues, BIAM, CEA, CNRS, Aix Marseille Univ, F-13108 Saint-Paul-lez-Durance, France
| | - Stéphanie Blangy
- Laboratoire de Bioénergétique et de Biotechnologie des Microalgues, BIAM, CEA, CNRS, Aix Marseille Univ, F-13108 Saint-Paul-lez-Durance, France
| | - Thomas Happe
- AG Photobiotechnologie, Lehrstuhl für Biochemie der Pflanzen, Fakultät für Biologie und Biotechnologie, Ruhr-Universität Bochum, 44801 Bochum, Germany
| | - Gilles Peltier
- Laboratoire de Bioénergétique et de Biotechnologie des Microalgues, BIAM, CEA, CNRS, Aix Marseille Univ, F-13108 Saint-Paul-lez-Durance, France
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