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Levin G, Yasmin M, Pieńko T, Yehishalom N, Hanna R, Kleifeld O, Glaser F, Schuster G. The protein phosphorylation landscape in photosystem I of the desert algae Chlorella sp. THE NEW PHYTOLOGIST 2024; 242:544-557. [PMID: 38379464 DOI: 10.1111/nph.19603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 01/28/2024] [Indexed: 02/22/2024]
Abstract
The phosphorylation of photosystem II (PSII) and its antenna (LHCII) proteins has been studied, and its involvement in state transitions and PSII repair is known. Yet, little is known about the phosphorylation of photosystem I (PSI) and its antenna (LHCI) proteins. Here, we applied proteomics analysis to generate a map of the phosphorylation sites of the PSI-LHCI proteins in Chlorella ohadii cells that were grown under low or extreme high-light intensities (LL and HL). Furthermore, we analyzed the content of oxidized tryptophans and PSI-LHCI protein degradation products in these cells, to estimate the light-induced damage to PSI-LHCI. Our work revealed the phosphorylation of 17 of 22 PSI-LHCI subunits. The analyses detected the extensive phosphorylation of the LHCI subunits Lhca6 and Lhca7, which is modulated by growth light intensity. Other PSI-LHCI subunits were phosphorylated to a lesser extent, including PsaE, where molecular dynamic simulation proposed that a phosphoserine stabilizes ferredoxin binding. Additionally, we show that HL-grown cells accumulate less oxidative damage and degradation products of PSI-LHCI proteins, compared with LL-grown cells. The significant phosphorylation of Lhca6 and Lhca7 at the interface with other LHCI subunits suggests a physiological role during photosynthesis, possibly by altering light-harvesting characteristics and binding of other subunits.
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Affiliation(s)
- Guy Levin
- Faculty of Biology, Technion, Haifa, 32000, Israel
| | | | - Tomasz Pieńko
- Schulich Faculty of Chemistry, Technion, Haifa, 32000, Israel
| | | | - Rawad Hanna
- Faculty of Biology, Technion, Haifa, 32000, Israel
| | | | - Fabian Glaser
- The Lorry I. Lokey Center for Life Sciences and Engineering, Technion, Haifa, 32000, Israel
| | - Gadi Schuster
- Faculty of Biology, Technion, Haifa, 32000, Israel
- Grand Technion Energy Program, Technion, Haifa, 32000, Israel
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2
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Findinier J, Joubert LM, Schmid MF, Malkovskiy A, Chiu W, Burlacot A, Grossman AR. Dramatic Changes in Mitochondrial Subcellular Location and Morphology Accompany Activation of the CO 2 Concentrating Mechanism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.25.586705. [PMID: 38585955 PMCID: PMC10996633 DOI: 10.1101/2024.03.25.586705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Dynamic changes in intracellular ultrastructure can be critical for the ability of organisms to acclimate to environmental conditions. Microalgae, which are responsible for ~50% of global photosynthesis, compartmentalize their Rubisco into a specialized structure known as the pyrenoid when the cells experience limiting CO2 conditions; this compartmentalization appears to be a component of the CO2 Concentrating Mechanism (CCM), which facilitates photosynthetic CO2 fixation as environmental levels of inorganic carbon (Ci) decline. Changes in the spatial distribution of mitochondria in green algae have also been observed under CO2 limiting conditions, although a role for this reorganization in CCM function remains unclear. We used the green microalgae Chlamydomonas reinhardtii to monitor changes in the position and ultrastructure of mitochondrial membranes as cells transition between high CO2 (HC) and Low/Very Low CO2 (LC/VLC). Upon transferring cells to VLC, the mitochondria move from a central to a peripheral location, become wedged between the plasma membrane and chloroplast envelope, and mitochondrial membranes orient in parallel tubular arrays that extend from the cell's apex to its base. We show that these ultrastructural changes require protein and RNA synthesis, occur within 90 min of shifting cells to VLC conditions, correlate with CCM induction and are regulated by the CCM master regulator CIA5. The apico-basal orientation of the mitochondrial membrane, but not the movement of the mitochondrion to the cell periphery, is dependent on microtubules and the MIRO1 protein, which is involved in membrane-microtubule interactions. Furthermore, blocking mitochondrial electron transport in VLC acclimated cells reduces the cell's affinity for inorganic carbon. Overall, our results suggest that CIA5-dependent mitochondrial repositioning/reorientation functions in integrating cellular architecture and energetics with CCM activities and invite further exploration of how intracellular architecture can impact fitness under dynamic environmental conditions.
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Affiliation(s)
- Justin Findinier
- The Carnegie Institution for Science, Biosphere Sciences & Engineering, Stanford, CA 94305, USA
| | - Lydia-Marie Joubert
- SLAC National Accelerator Laboratory, Division of CryoEM and Bioimaging, Menlo Park, CA 94025, USA
| | - Michael F. Schmid
- SLAC National Accelerator Laboratory, Division of CryoEM and Bioimaging, Menlo Park, CA 94025, USA
| | - Andrey Malkovskiy
- The Carnegie Institution for Science, Biosphere Sciences & Engineering, Stanford, CA 94305, USA
| | - Wah Chiu
- SLAC National Accelerator Laboratory, Division of CryoEM and Bioimaging, Menlo Park, CA 94025, USA
- Stanford University, Department of Bioengineering, Stanford, CA 94305, USA
| | - Adrien Burlacot
- The Carnegie Institution for Science, Biosphere Sciences & Engineering, Stanford, CA 94305, USA
- Stanford University, Biology Department, Stanford, CA 94305, USA
| | - Arthur R. Grossman
- The Carnegie Institution for Science, Biosphere Sciences & Engineering, Stanford, CA 94305, USA
- Stanford University, Biology Department, Stanford, CA 94305, USA
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Murik O, Geffen O, Shotland Y, Fernandez-Pozo N, Ullrich KK, Walther D, Rensing SA, Treves H. Genomic imprints of unparalleled growth. THE NEW PHYTOLOGIST 2024; 241:1144-1160. [PMID: 38072860 DOI: 10.1111/nph.19444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 10/31/2023] [Indexed: 12/23/2023]
Abstract
Chlorella ohadii was isolated from desert biological soil crusts, one of the harshest habitats on Earth, and is emerging as an exciting new green model for studying growth, photosynthesis and metabolism under a wide range of conditions. Here, we compared the genome of C. ohadii, the fastest growing alga on record, to that of other green algae, to reveal the genomic imprints empowering its unparalleled growth rate and resistance to various stressors, including extreme illumination. This included the genome of its close relative, but slower growing and photodamage sensitive, C. sorokiniana UTEX 1663. A larger number of ribosome-encoding genes, high intron abundance, increased codon bias and unique genes potentially involved in metabolic flexibility and resistance to photodamage are all consistent with the faster growth of C. ohadii. Some of these characteristics highlight general trends in Chlorophyta and Chlorella spp. evolution, and others open new broad avenues for mechanistic exploration of their relationship with growth. This work entails a unique case study for the genomic adaptations and costs of exceptionally fast growth and sheds light on the genomic signatures of fast growth in photosynthetic cells. It also provides an important resource for future studies leveraging the unique properties of C. ohadii for photosynthesis and stress response research alongside their utilization for synthetic biology and biotechnology aims.
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Affiliation(s)
- Omer Murik
- Department of Plant and Environmental Sciences, Hebrew University of Jerusalem, 91904, Jerusalem, Israel
- Medical Genetics Institute, Shaare Zedek Medical Center, 93722, Jerusalem, Israel
| | - Or Geffen
- School of Plant Sciences and Food Security, Tel-Aviv University, 39040, Tel-Aviv, Israel
| | - Yoram Shotland
- Chemical Engineering, Shamoon College of Engineering, 84100, Beer-Sheva, Israel
| | - Noe Fernandez-Pozo
- Plant Cell Biology, Department of Biology, University of Marburg, 35037, Marburg, Germany
| | - Kristian Karsten Ullrich
- Plant Cell Biology, Department of Biology, University of Marburg, 35037, Marburg, Germany
- Max-Planck Institute for Evolutionary Biology, 24306, Plön, Germany
| | - Dirk Walther
- Max-Planck Institute for Molecular Plant Physiology, 14476, Potsdam, Germany
| | - Stefan Andreas Rensing
- Plant Cell Biology, Department of Biology, University of Marburg, 35037, Marburg, Germany
- Center for Biological Signaling Studies (BIOSS), University of Freiburg, 79098, Freiburg, Germany
| | - Haim Treves
- School of Plant Sciences and Food Security, Tel-Aviv University, 39040, Tel-Aviv, Israel
- Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, 67663, Kaiserslautern, Germany
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Fadeeva M, Klaiman D, Caspy I, Nelson N. Structure of Chlorella ohadii Photosystem II Reveals Protective Mechanisms against Environmental Stress. Cells 2023; 12:1971. [PMID: 37566050 PMCID: PMC10416949 DOI: 10.3390/cells12151971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 07/23/2023] [Accepted: 07/29/2023] [Indexed: 08/12/2023] Open
Abstract
Green alga Chlorella ohadii is known for its ability to carry out photosynthesis under harsh conditions. Using cryogenic electron microscopy (cryoEM), we obtained a high-resolution structure of PSII at 2.72 Å. This structure revealed 64 subunits, which encompassed 386 chlorophylls, 86 carotenoids, four plastoquinones, and several structural lipids. At the luminal side of PSII, a unique subunit arrangement was observed to protect the oxygen-evolving complex. This arrangement involved PsbO (OEE1), PsbP (OEE2), PsbB, and PsbU (a homolog of plant OEE3). PsbU interacted with PsbO, PsbC, and PsbP, thereby stabilizing the shield of the oxygen-evolving complex. Significant changes were also observed at the stromal electron acceptor side. PsbY, identified as a transmembrane helix, was situated alongside PsbF and PsbE, which enclosed cytochrome b559. Supported by the adjacent C-terminal helix of Psb10, these four transmembrane helices formed a bundle that shielded cytochrome b559 from the surrounding solvent. Moreover, the bulk of Psb10 formed a protective cap, which safeguarded the quinone site and likely contributed to the stacking of PSII complexes. Based on our findings, we propose a protective mechanism that prevents QB (plastoquinone B) from becoming fully reduced. This mechanism offers insights into the regulation of electron transfer within PSII.
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Affiliation(s)
| | | | | | - Nathan Nelson
- Department of Biochemistry and Molecular Biology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel; (M.F.); (D.K.); (I.C.)
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Fadeeva M, Klaiman D, Caspy I, Nelson N. CryoEM PSII structure reveals adaptation mechanisms to environmental stress in Chlorella ohadii. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.04.539358. [PMID: 37205566 PMCID: PMC10187303 DOI: 10.1101/2023.05.04.539358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Performing photosynthesis in the desert is a challenging task since it requires a fast adaptation to extreme illumination and temperature changes. To understand adaptive mechanisms, we purified Photosystem II (PSII) from Chlorella ohadii , a green alga from the desert soil surface, and identified structural elements that might enable the photosystem functioning under harsh conditions. The 2.72 Å cryogenic electron-microscopy (cryoEM) structure of PSII exhibited 64 subunits, encompassing 386 chlorophylls, 86 carotenoids, four plastoquinones, and several structural lipids. At the luminal side of PSII, the oxygen evolving complex was protected by a unique subunit arrangement - PsbO (OEE1), PsbP (OEE2), CP47, and PsbU (plant OEE3 homolog). PsbU interacted with PsbO, CP43, and PsbP, thus stabilising the oxygen evolving shield. Substantial changes were observed on the stromal electron acceptor side - PsbY was identified as a transmembrane helix situated alongside PsbF and PsbE enclosing cytochrome b559, supported by the adjacent C-terminal helix of Psb10. These four transmembrane helices bundled jointly, shielding cytochrome b559 from the solvent. The bulk of Psb10 formed a cap protecting the quinone site and probably contributed to the PSII stacking. So far, the C. ohadii PSII structure is the most complete description of the complex, suggesting numerous future experiments. A protective mechanism that prevented Q B from rendering itself fully reduced is proposed.
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Affiliation(s)
| | | | - Ido Caspy
- Department of Biochemistry and Molecular Biology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Nathan Nelson
- Department of Biochemistry and Molecular Biology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, 69978 Tel Aviv, Israel
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Zournas A, Mani K, Dismukes GC. Cyclic electron flow around photosystem II in silico: How it works and functions in vivo. PHOTOSYNTHESIS RESEARCH 2023; 156:129-145. [PMID: 36753032 DOI: 10.1007/s11120-023-00997-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 12/29/2022] [Indexed: 06/18/2023]
Abstract
To date, cyclic electron flow around PSI (PSI-CEF) has been considered the primary (if not the only) mechanism accepted to adjust the ratio of linear vs cyclic electron flow that is essential to adjust the ratio of ATP/NADPH production needed for CO2 carboxylation. Here we provide a kinetic model showing that cyclic electron flow within PSII (PSII-CEF) is essential to account for the accelerating rate of decay in flash-induced oscillations of O2 yield as the PQ pool progressively reduces to PQH2. Previously, PSII-CEF was modeled by backward transitions using empirical Markov models like Joliot-Kok (J-K) type. Here, we adapted an ordinary differential equation methodology denoted RODE1 to identify which microstates within PSII are responsible for branching between PSII-CEF and Linear Electron Flow (LEF). We applied it to simulate the oscillations of O2 yield from both Chlorella ohadii, an alga that shows strong PSII-CEF attributed to high backward transitions, and Synechococcus elongatus sp. 7002, a widely studied model cyanobacterium. RODE2 simulations reveal that backward transitions occur in microstates that possess a QB- semiquinone prior to the flash. Following a flash that forms microstates populating (QAQB)2-, PSII-CEF redirects these two electrons to the donor side of PSII only when in the oxidized S2 and S3 states. We show that this backward transition pathway is the origin of the observed period-2 oscillations of flash O2 yield and contributes to the accelerated decay of period-4 oscillations. This newly added pathway improved RODE1 fits for cells of both S. elongatus and C. ohadii. RODE2 simulations show that cellular adaptation to high light intensity growth is due to a decrease in QB availability (empty or blocked by Q2-B), or equivalently due to a decrease in the difference in reduction potential relative to QA/QA-. PSII-CEF provides an alternative mechanism for rebalancing the NADPH:ATP ratio that occurs rapidly by adjusting the redox level of the PQ:PQH2 pool and is a necessary process for energy metabolism in aquatic phototrophs.
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Affiliation(s)
- Apostolos Zournas
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, 08854, USA
- Department of Chemical and Biological Engineering, Rutgers University, Piscataway, NJ, 08854, USA
| | - Kyle Mani
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, 08854, USA
| | - G Charles Dismukes
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, 08854, USA.
- Department. of Chemistry & Chemical Biology, Rutgers University, Piscataway, NJ, 08854, USA.
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7
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Zhou Y, Meng F, Han K, Zhang K, Gao J, Chen F. Screening and validating of endogenous reference genes in Chlorella sp. TLD 6B under abiotic stress. Sci Rep 2023; 13:1555. [PMID: 36707665 PMCID: PMC9883494 DOI: 10.1038/s41598-023-28311-x] [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: 09/27/2022] [Accepted: 01/17/2023] [Indexed: 01/28/2023] Open
Abstract
Chlorella sp. TLD 6B, a microalgae growing in the Taklamakan Desert, Xinjiang of China, is a good model material for studying the physiological and environmental adaptation mechanisms of plants in their arid habitats, as its adaptation to the harsh desert environment has led to its strong resistance. However, when using real-time quantitative polymerase chain reaction (RT-qPCR) to analyze the gene expression of this algae under abiotic stress, it is essential to find the suitable endogenous reference genes so to obtain reliable results. This study assessed the expression stability of 9 endogenous reference genes of Chlorella sp. TLD 6B under four abiotic stresses (drought, salt, cold and heat). These genes were selected based on the analysis results calculated by the three algorithmic procedures of geNorm, NormFinder, and BestKeeper, which were ranked by refinder. Our research showed that 18S and GTP under drought stress, 18S and IDH under salt stress, CYP and 18S under cold stress, GTP and IDH under heat stress were the most stable endogenous reference genes. Moreover, UBC and 18S were the most suitable endogenous reference gene combinations for all samples. In contrast, GAPDH and α-TUB were the two least stable endogenous reference genes in all experimental samples. Additionally, the selected genes have been verified to be durable and reliable by detecting POD and PXG3 genes using above endogenous reference genes. The identification of reliable endogenous reference genes guarantees more accurate RT-qPCR quantification for Chlorella sp. TLD 6B, facilitating functional genomics studies of deserts Chlorella as well as the mining of resistance genes.
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Affiliation(s)
- Yongshun Zhou
- College of Life Sciences, Shihezi University, Shihezi, Xinjiang, 832000, People's Republic of China
| | - Fanze Meng
- College of Life Sciences, Shihezi University, Shihezi, Xinjiang, 832000, People's Republic of China
| | - Kai Han
- College of Life Sciences, Shihezi University, Shihezi, Xinjiang, 832000, People's Republic of China
| | - Kaiyue Zhang
- College of Life Sciences, Shihezi University, Shihezi, Xinjiang, 832000, People's Republic of China
| | - Jianfeng Gao
- College of Life Sciences, Shihezi University, Shihezi, Xinjiang, 832000, People's Republic of China.
| | - Fulong Chen
- College of Life Sciences, Shihezi University, Shihezi, Xinjiang, 832000, People's Republic of China.
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8
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Light-Dependent Nitrate Removal Capacity of Green Microalgae. Int J Mol Sci 2022; 24:ijms24010077. [PMID: 36613517 PMCID: PMC9820755 DOI: 10.3390/ijms24010077] [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: 11/29/2022] [Revised: 12/13/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
In the present study, Chlamydomonas sp. MACC-216 was used to investigate total nitrate removal in TAP medium with sodium nitrate as the sole nitrogen source under several light conditions made up of permuted combinations of three light colors (referred to as blue, red, and white light) and three light intensities (50 µmol m-2 s-1, 100 µmol m-2 s-1, and 250 µmol m-2 s-1). It was observed that nitrate removal efficiency is influenced by light color as well as light intensity. Additionally, Chlamydomonas sp. MACC-216 was cultivated in synthetic wastewater under four light conditions, namely, Blue 250, Blue 125 + Red 125, Red 250, and White 250, where it showed the highest nitrate removal efficiency and nitrate reductase activity under the Blue 125 + Red 125 light condition. To observe the impact of light color on the nitrate removal capacity of Chlamydomonas sp. MACC-216, the expression of five genes participating in nitrate transport and reduction (NRT1, NRT2.1, NRT2.2, NIA, and MCP) was also analyzed; these genes showed the highest expression under the Blue 125 + Red 125 light condition. Based on the above-mentioned findings, the blue + red light combination emerged as a promising light combination for nitrate removal. Hence, our study suggests the importance of the blue + red light combination together with high light intensity, as the optimal light condition for nitrate removal from synthetic wastewater in comparison to other monochromatic lights with high light intensity.
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Jebali A, Sanchez MR, Hanschen ER, Starkenburg SR, Corcoran AA. Trait drift in microalgae and applications for strain improvement. Biotechnol Adv 2022; 60:108034. [PMID: 36089253 DOI: 10.1016/j.biotechadv.2022.108034] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 08/06/2022] [Accepted: 09/05/2022] [Indexed: 11/29/2022]
Abstract
Microalgae are increasingly used to generate a wide range of commercial products, and there is growing evidence that microalgae-based products can be produced sustainably. However, industrial production of microalgal biomass is not as developed as other biomanufacturing platform technologies. In addition, results of bench-scale research often fail to translate to large-scale or mass production systems. This disconnect may result from trait drift and evolution occurring, through time, in response to unique drivers in each environment, such as cultivation regimes, weather, and pests. Moreover, outdoor and indoor cultivation of microalgae has the potential to impose negative selection pressures, which makes the maintenance of desired traits a challenge. In this context, this review sheds the light on our current understanding of trait drift and evolution in microalgae. We delineate the basics of phenotype plasticity and evolution, with a focus on how microalgae respond under various conditions. In addition, we review techniques that exploit phenotypic plasticity and evolution for strain improvement in view of industrial commercial applications, highlighting associated advantages and shortcomings. Finally, we suggest future research directions and recommendations to overcome unwanted trait drift and evolution in microalgae cultivation.
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Affiliation(s)
- Ahlem Jebali
- New Mexico Consortium, 4200 W. Jemez Road, Los Alamos, NM 87544, USA.
| | - Monica R Sanchez
- Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, USA
| | - Erik R Hanschen
- Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, USA
| | | | - Alina A Corcoran
- New Mexico Consortium, 4200 W. Jemez Road, Los Alamos, NM 87544, USA
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Wang B, Ye T, Li C, Li X, Chen L, Wang G. Cell damage repair mechanism in a desert green algae Chlorella sp. against UV-B radiation. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 242:113916. [PMID: 35878498 DOI: 10.1016/j.ecoenv.2022.113916] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 07/18/2022] [Accepted: 07/20/2022] [Indexed: 06/15/2023]
Abstract
The protective ozone layer is continually depleting owing to an increase in the levels of solar UV-B radiation, which has harmful effects on organisms. Algae in desert soil can resist UV-B radiation, but most research on the radiation resistance of desert algae has focused on cyanobacteria. In this study, we found that desert green algae, Chlorella sp., could maintain high photosynthetic activity under UV-B stress. To examine the tolerance mechanism of the desert green algae photosystem, we observed the physiological and transcriptome-level responses of Chlorella sp. to high doses of UV-B radiation. The results showed that the reactive oxygen species (ROS) content first increased and then decreased, while the malondialdehyde (MDA) content revealed no notable lipid peroxidation during the UV-B exposure period. These results suggested that Chlorella sp. may have strong system characteristics for scavenging ROS. The antioxidant enzyme system showed efficient alternate coordination, which exhibited a protective effect against enhanced UV-B radiation. DNA damage and the chlorophyll and soluble protein contents had no significant changes in the early irradiation stage; UV-B radiation did not induce extracellular polysaccharides (EPS) synthesis. Transcriptomic data revealed that a strong photosynthetic system, efficient DNA repair, and changes in the expression of genes encoding ribosomal protein (which aid in protein synthesis and improve resistance) are responsible for the high UV-B tolerance characteristics of Chlorella sp. In contrast, EPS synthesis was not the main pathway for UV-B resistance. Our results revealed the potential cell damage repair mechanisms within Chlorella sp. that were associated with high intensity UV-B stress, thereby providing insights into the underlying regulatory adaptations of desert green algae.
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Affiliation(s)
- Bo Wang
- Jiangxi Key Laboratory of Industrial Ecological Simulation and Environmental Health in Yangtze River Basin, Jiujiang University, Jiujiang 332005, China; Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China; College of Resource & Environment, Jiujiang University, Jiujiang 332005, China
| | - Tong Ye
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Caiyan Li
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoyan Li
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lanzhou Chen
- School of Resource and Environmental Sciences, Hubei Key Laboratory of Biomass-Resources Chemistry and Environmental Biotechnology, Wuhan University, China
| | - Gaohong Wang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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11
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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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Hitchcock A, Hunter CN, Sobotka R, Komenda J, Dann M, Leister D. Redesigning the photosynthetic light reactions to enhance photosynthesis - the PhotoRedesign consortium. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 109:23-34. [PMID: 34709696 DOI: 10.1111/tpj.15552] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/12/2021] [Accepted: 10/21/2021] [Indexed: 06/13/2023]
Abstract
In this Perspective article, we describe the visions of the PhotoRedesign consortium funded by the European Research Council of how to enhance photosynthesis. The light reactions of photosynthesis in individual phototrophic species use only a fraction of the solar spectrum, and high light intensities can impair and even damage the process. In consequence, expanding the solar spectrum and enhancing the overall energy capacity of the process, while developing resilience to stresses imposed by high light intensities, could have a strong positive impact on food and energy production. So far, the complexity of the photosynthetic machinery has largely prevented improvements by conventional approaches. Therefore, there is an urgent need to develop concepts to redesign the light-harvesting and photochemical capacity of photosynthesis, as well as to establish new model systems and toolkits for the next generation of photosynthesis researchers. The overall objective of PhotoRedesign is to reconfigure the photosynthetic light reactions so they can harvest and safely convert energy from an expanded solar spectrum. To this end, a variety of synthetic biology approaches, including de novo design, will combine the attributes of photosystems from different photoautotrophic model organisms, namely the purple bacterium Rhodobacter sphaeroides, the cyanobacterium Synechocystis sp. PCC 6803 and the plant Arabidopsis thaliana. In parallel, adaptive laboratory evolution will be applied to improve the capacity of reimagined organisms to cope with enhanced input of solar energy, particularly in high and fluctuating light.
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Affiliation(s)
- Andrew Hitchcock
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Christopher Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Roman Sobotka
- Laboratory of Photosynthesis, Institute of Microbiology of the Czech Academy of Sciences, Třeboň, 37901, Czech Republic
| | - Josef Komenda
- Laboratory of Photosynthesis, Institute of Microbiology of the Czech Academy of Sciences, Třeboň, 37901, Czech Republic
| | - Marcel Dann
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried, 82152, Germany
| | - Dario Leister
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried, 82152, Germany
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13
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Maltsev Y, Maltseva K, Kulikovskiy M, Maltseva S. Influence of Light Conditions on Microalgae Growth and Content of Lipids, Carotenoids, and Fatty Acid Composition. BIOLOGY 2021; 10:1060. [PMID: 34681157 PMCID: PMC8533579 DOI: 10.3390/biology10101060] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/13/2021] [Accepted: 10/14/2021] [Indexed: 02/06/2023]
Abstract
Microalgae are a valuable natural resource for a variety of value-added products. The growth of microalgae is determined by the impact of many factors, but, from the point of view of the implementation of autotrophic growth, light is of primary importance. This work presents an overview of the influence of light conditions on the growth of microalgae, the content of lipids, carotenoids, and the composition of fatty acids in their biomass, taking into account parameters such as the intensity, duration of lighting, and use of rays of different spectral composition. The optimal light intensity for the growth of microalgae lies in the following range: 26-400 µmol photons m-2 s-1. An increase in light intensity leads to an activation of lipid synthesis. For maximum lipid productivity, various microalgae species and strains need lighting of different intensities: from 60 to 700 µmol photons m-2 s-1. Strong light preferentially increases the triacylglyceride content. The intensity of lighting has a regulating effect on the synthesis of fatty acids, carotenoids, including β-carotene, lutein and astaxanthin. In intense lighting conditions, saturated fatty acids usually accumulate, as well as monounsaturated ones, and the number of polyunsaturated fatty acids decreases. Red as well as blue LED lighting improves the biomass productivity of microalgae of various taxonomic groups. Changing the duration of the photoperiod, the use of pulsed light can stimulate microalgae growth, the production of lipids, and carotenoids. The simultaneous use of light and other stresses contributes to a stronger effect on the productivity of algae.
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Affiliation(s)
- Yevhen Maltsev
- Laboratory of Molecular Systematics of Aquatic Plants, K.A. Timiryazev Institute of Plant Physiology RAS, IPP RAS, 127276 Moscow, Russia; (M.K.); (S.M.)
| | - Kateryna Maltseva
- Faculty of Chemistry and Biology, Bogdan Khmelnitsky Melitopol State Pedagogical University, 72312 Melitopol, Ukraine;
| | - Maxim Kulikovskiy
- Laboratory of Molecular Systematics of Aquatic Plants, K.A. Timiryazev Institute of Plant Physiology RAS, IPP RAS, 127276 Moscow, Russia; (M.K.); (S.M.)
| | - Svetlana Maltseva
- Laboratory of Molecular Systematics of Aquatic Plants, K.A. Timiryazev Institute of Plant Physiology RAS, IPP RAS, 127276 Moscow, Russia; (M.K.); (S.M.)
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14
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Cecchin M, Paloschi M, Busnardo G, Cazzaniga S, Cuine S, Li‐Beisson Y, Wobbe L, Ballottari M. CO 2 supply modulates lipid remodelling, photosynthetic and respiratory activities in Chlorella species. PLANT, CELL & ENVIRONMENT 2021; 44:2987-3001. [PMID: 33931891 PMCID: PMC8453743 DOI: 10.1111/pce.14074] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 04/20/2021] [Accepted: 04/23/2021] [Indexed: 05/28/2023]
Abstract
Microalgae represent a potential solution to reduce CO2 emission exploiting their photosynthetic activity. Here, the physiologic and metabolic responses at the base of CO2 assimilation were investigated in conditions of high or low CO2 availability in two of the most promising algae species for industrial cultivation, Chlorella sorokiniana and Chlorella vulgaris. In both species, high CO2 availability increased biomass accumulation with specific increase of triacylglycerols in C. vulgaris and polar lipids and proteins in C. sorokiniana. Moreover, high CO2 availability caused only in C. vulgaris a reduced NAD(P)H/NADP+ ratio and reduced mitochondrial respiration, suggesting a CO2 dependent increase of reducing power consumption in the chloroplast, which in turn influences the redox state of the mitochondria. Several rearrangements of the photosynthetic machinery were observed in both species, differing from those described for the model organism Chlamydomonas reinhardtii, where adaptation to carbon availability is mainly controlled by the translational repressor NAB1. NAB1 homologous protein could be identified only in C. vulgaris but lacked the regulation mechanisms previously described in C. reinhardtii. Acclimation strategies to cope with a fluctuating inorganic carbon supply are thus diverse among green microalgae, and these results suggest new biotechnological strategies to boost CO2 fixation.
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Affiliation(s)
- Michela Cecchin
- Dipartimento di BiotecnologieUniversità di VeronaVeronaItaly
| | - Matteo Paloschi
- Dipartimento di BiotecnologieUniversità di VeronaVeronaItaly
| | | | | | - Stephan Cuine
- Aix‐Marseille Univ., CEA, CNRSInstitute of Biosciences and Biotechnologies of Aix‐Marseille, UMR7265, CEA CadaracheSaint‐Paul‐lez DuranceFrance
| | - Yonghua Li‐Beisson
- Aix‐Marseille Univ., CEA, CNRSInstitute of Biosciences and Biotechnologies of Aix‐Marseille, UMR7265, CEA CadaracheSaint‐Paul‐lez DuranceFrance
| | - Lutz Wobbe
- Bielefeld UniversityCenter for Biotechnology (CeBiTec), Faculty of BiologyBielefeldGermany
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15
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Caspy I, Neumann E, Fadeeva M, Liveanu V, Savitsky A, Frank A, Kalisman YL, Shkolnisky Y, Murik O, Treves H, Hartmann V, Nowaczyk MM, Schuhmann W, Rögner M, Willner I, Kaplan A, Schuster G, Nelson N, Lubitz W, Nechushtai R. Cryo-EM photosystem I structure reveals adaptation mechanisms to extreme high light in Chlorella ohadii. NATURE PLANTS 2021; 7:1314-1322. [PMID: 34462576 DOI: 10.1038/s41477-021-00983-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 07/07/2021] [Indexed: 05/10/2023]
Abstract
Photosynthesis in deserts is challenging since it requires fast adaptation to rapid night-to-day changes, that is, from dawn's low light (LL) to extreme high light (HL) intensities during the daytime. To understand these adaptation mechanisms, we purified photosystem I (PSI) from Chlorella ohadii, a green alga that was isolated from a desert soil crust, and identified the essential functional and structural changes that enable the photosystem to perform photosynthesis under extreme high light conditions. The cryo-electron microscopy structures of PSI from cells grown under low light (PSILL) and high light (PSIHL), obtained at 2.70 and 2.71 Å, respectively, show that part of light-harvesting antenna complex I (LHCI) and the core complex subunit (PsaO) are eliminated from PSIHL to minimize the photodamage. An additional change is in the pigment composition and their number in LHCIHL; about 50% of chlorophyll b is replaced by chlorophyll a. This leads to higher electron transfer rates in PSIHL and might enable C. ohadii PSI to act as a natural photosynthesiser in photobiocatalytic systems. PSIHL or PSILL were attached to an electrode and their induced photocurrent was determined. To obtain photocurrents comparable with PSIHL, 25 times the amount of PSILL was required, demonstrating the high efficiency of PSIHL. Hence, we suggest that C. ohadii PSIHL is an ideal candidate for the design of desert artificial photobiocatalytic systems.
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Affiliation(s)
- Ido Caspy
- Department of Biochemistry, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Ehud Neumann
- Institute of Life Science, Faculty of Science and Mathematics, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Maria Fadeeva
- Department of Biochemistry, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Varda Liveanu
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Anton Savitsky
- Faculty of Physics, Technical University Dortmund, Dortmund, Germany
- Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr, Germany
| | - Anna Frank
- Plant Biochemistry, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Yael Levi Kalisman
- Institute of Life Science, Faculty of Science and Mathematics, The Hebrew University of Jerusalem, Jerusalem, Israel
- The Centre for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yoel Shkolnisky
- School of Mathematical Sciences, Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Omer Murik
- Institute of Life Science, Faculty of Science and Mathematics, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Haim Treves
- Institute of Life Science, Faculty of Science and Mathematics, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Volker Hartmann
- Plant Biochemistry, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Marc M Nowaczyk
- Plant Biochemistry, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Wolfgang Schuhmann
- Analytical Chemistry-Centre for Electrochemical Sciences (CES), Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Bochum, Germany
| | - Matthias Rögner
- Plant Biochemistry, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Itamar Willner
- Institute of Life Science, Faculty of Science and Mathematics, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Aaron Kaplan
- Institute of Life Science, Faculty of Science and Mathematics, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Gadi Schuster
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Nathan Nelson
- Department of Biochemistry, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.
| | - Wolfgang Lubitz
- Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr, Germany.
| | - Rachel Nechushtai
- Institute of Life Science, Faculty of Science and Mathematics, The Hebrew University of Jerusalem, Jerusalem, Israel.
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16
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Havurinne V, Handrich M, Antinluoma M, Khorobrykh S, Gould SB, Tyystjärvi E. Genetic autonomy and low singlet oxygen yield support kleptoplast functionality in photosynthetic sea slugs. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:5553-5568. [PMID: 33989402 PMCID: PMC8318255 DOI: 10.1093/jxb/erab216] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 05/12/2021] [Indexed: 05/04/2023]
Abstract
The kleptoplastic sea slug Elysia chlorotica consumes Vaucheria litorea, stealing its plastids, which then photosynthesize inside the animal cells for months. We investigated the properties of V. litorea plastids to understand how they withstand the rigors of photosynthesis in isolation. Transcription of specific genes in laboratory-isolated V. litorea plastids was monitored for 7 days. The involvement of plastid-encoded FtsH, a key plastid maintenance protease, in recovery from photoinhibition in V. litorea was estimated in cycloheximide-treated cells. In vitro comparison of V. litorea and spinach thylakoids was applied to investigate reactive oxygen species formation in V. litorea. In comparison to other tested genes, the transcripts of ftsH and translation elongation factor EF-Tu (tufA) decreased slowly in isolated V. litorea plastids. Higher levels of FtsH were also evident in cycloheximide-treated cells during recovery from photoinhibition. Charge recombination in PSII of V. litorea was found to be fine-tuned to produce only small quantities of singlet oxygen, and the plastids also contained reactive oxygen species-protective compounds. Our results support the view that the genetic characteristics of the plastids are crucial in creating a photosynthetic sea slug. The plastid's autonomous repair machinery is likely enhanced by low singlet oxygen production and elevated expression of FtsH.
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Affiliation(s)
- Vesa Havurinne
- Department of Biotechnology/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Maria Handrich
- Department of Biology, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Mikko Antinluoma
- Department of Biotechnology/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Sergey Khorobrykh
- Department of Biotechnology/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Sven B Gould
- Department of Biology, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Esa Tyystjärvi
- Department of Biotechnology/Molecular Plant Biology, University of Turku, Turku, Finland
- Correspondence:
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17
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Supra-Optimal Temperature: An Efficient Approach for Overaccumulation of Starch in the Green Alga Parachlorella kessleri. Cells 2021; 10:cells10071806. [PMID: 34359975 PMCID: PMC8306380 DOI: 10.3390/cells10071806] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/11/2021] [Accepted: 07/12/2021] [Indexed: 11/25/2022] Open
Abstract
Green algae are fast-growing microorganisms that are considered promising for the production of starch and neutral lipids, and the chlorococcal green alga Parachlorella kessleri is a favorable model, as it can produce both starch and neutral lipids. P. kessleri commonly divides into more than two daughter cells by a specific mechanism—multiple fission. Here, we used synchronized cultures of the alga to study the effects of supra-optimal temperature. Synchronized cultures were grown at optimal (30 °C) and supra-optimal (40 °C) temperatures and incident light intensities of 110 and 500 μmol photons m−2 s−1. The time course of cell reproduction (DNA replication, cellular division), growth (total RNA, protein, cell dry matter, cell size), and synthesis of energy reserves (net starch, neutral lipid) was studied. At 40 °C, cell reproduction was arrested, but growth and accumulation of energy reserves continued; this led to the production of giant cells enriched in protein, starch, and neutral lipids. Furthermore, we examined whether the increased temperature could alleviate the effects of deuterated water on Parachlorella kessleri growth and division; results show that supra-optimal temperature can be used in algal biotechnology for the production of protein, (deuterated) starch, and neutral lipids.
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18
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Levin G, Kulikovsky S, Liveanu V, Eichenbaum B, Meir A, Isaacson T, Tadmor Y, Adir N, Schuster G. The desert green algae Chlorella ohadii thrives at excessively high light intensities by exceptionally enhancing the mechanisms that protect photosynthesis from photoinhibition. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 106:1260-1277. [PMID: 33725388 DOI: 10.1111/tpj.15232] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 03/09/2021] [Accepted: 03/11/2021] [Indexed: 06/12/2023]
Abstract
Although light is the driving force of photosynthesis, excessive light can be harmful. One of the main processes that limits photosynthesis is photoinhibition, the process of light-induced photodamage. When the absorbed light exceeds the amount that is dissipated by photosynthetic electron flow and other processes, damaging radicals are formed that mostly inactivate photosystem II (PSII). Damaged PSII must be replaced by a newly repaired complex in order to preserve full photosynthetic activity. Chlorella ohadii is a green microalga, isolated from biological desert soil crusts, that thrives under extreme high light and is highly resistant to photoinhibition. Therefore, C. ohadii is an ideal model for studying the molecular mechanisms underlying protection against photoinhibition. Comparison of the thylakoids of C. ohadii cells that were grown under low light versus extreme high light intensities found that the alga employs all three known photoinhibition protection mechanisms: (i) massive reduction of the PSII antenna size; (ii) accumulation of protective carotenoids; and (iii) very rapid repair of photodamaged reaction center proteins. This work elucidated the molecular mechanisms of photoinhibition resistance in one of the most light-tolerant photosynthetic organisms, and shows how photoinhibition protection mechanisms evolved to marginal conditions, enabling photosynthesis-dependent life in severe habitats.
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Affiliation(s)
- Guy Levin
- Faculty of Biology, Technion, Haifa, 32000, Israel
| | | | | | | | - Ayala Meir
- Department of Vegetable Research, Agricultural Research Organization, Newe Ya'ar Research Center, Ramat Yishay, Israel
| | - Tal Isaacson
- Department of Vegetable Research, Agricultural Research Organization, Newe Ya'ar Research Center, Ramat Yishay, Israel
| | - Yaakov Tadmor
- Department of Vegetable Research, Agricultural Research Organization, Newe Ya'ar Research Center, Ramat Yishay, Israel
| | - Noam Adir
- Grand Technion Energy Program, Technion, Haifa, 32000, Israel
- Schulich Faculty of Chemistry, Technion, Haifa, 32000, Israel
| | - Gadi Schuster
- Faculty of Biology, Technion, Haifa, 32000, Israel
- Grand Technion Energy Program, Technion, Haifa, 32000, Israel
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19
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Abstract
Since the 1950s, microalgae have been grown commercially in man-made cultivation units and used for biomass production as a source of food and feed supplements, pharmaceuticals, cosmetics and lately biofuels, as well as a means for wastewater treatment and mitigation of atmospheric CO2 build-up. In this work, photosynthesis and growth affecting variables—light intensity, pH, CO2/O2 exchange, nutrient supply, culture turbulence, light/dark cell cycling, biomass density and culture depth (light path)—are reviewed as concerns in microalgae mass cultures. Various photosynthesis monitoring techniques were employed to study photosynthetic performance to optimize the growth of microalgae strains in outdoor cultivation units. The most operative and reliable techniques appeared to be fast-response ones based on chlorophyll fluorescence and oxygen production monitoring, which provide analogous results.
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20
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Wang B, Ye T, Li X, Bian P, Liu Y, Wang G. Survival of desert algae Chlorella exposed to Mars-like near space environment. LIFE SCIENCES IN SPACE RESEARCH 2021; 29:22-29. [PMID: 33888284 DOI: 10.1016/j.lssr.2021.02.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 02/05/2021] [Accepted: 02/12/2021] [Indexed: 06/12/2023]
Abstract
Desert was considered terrestrial analogues of Mars. In this study, dried cells of desert green algae Chlorella were exposed to Mars-like near-space environment using high-altitude scientific balloons. We found that while a majority of Chlorella cells survived, they exhibited considerable damage, such as low photosynthetic activity, reduced cell growth, increased cell mortality rate, and altered chloroplast and mitochondrial ultrastructure. Additionally, transcriptome analysis of near space-exposed Chlorella cells revealed 3292 differentially expressed genes compared to cells in the control ground group, including heat shock proteins, antioxidant enzymes, DNA repair systems, as well as proteins related to the PSII apparatus and ribosomes. These data shed light on the possible survival strategy of desert algae to near space environments. Our results indicated that Mars-like near space conditions represent an extreme environment for desert algae in terms of temperature, pressure, and radiations. The survival strategy of Chlorella in response to near space will help gain insights into the possibility of extremophile colonization on the surface of Mars and in similar extraterrestrial habitats.
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Affiliation(s)
- Bo Wang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tong Ye
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoyan Li
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Po Bian
- Key Laboratory of Ion Beam Bio-engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui 230031, China
| | - Yongding Liu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Gaohong Wang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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21
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Vishnivetskaya TA, Almatari AL, Spirina EV, Wu X, Williams DE, Pfiffner SM, Rivkina EM. Insights into community of photosynthetic microorganisms from permafrost. FEMS Microbiol Ecol 2021; 96:5979775. [PMID: 33181853 DOI: 10.1093/femsec/fiaa229] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 11/10/2020] [Indexed: 02/07/2023] Open
Abstract
This work integrates cultivation studies of Siberian permafrost and analyses of metagenomes from different locations in the Arctic with the aim of obtaining insights into the community of photosynthetic microorganisms in perennially frozen deposits. Cyanobacteria and microalgae have been described in Arctic aquatic and surface soil environments, but their diversity and ability to withstand harsh conditions within the permafrost are still largely unknown. Community structure of photosynthetic organisms in permafrost sediments was explored using Arctic metagenomes available through the MG-RAST. Sequences affiliated with cyanobacteria represented from 0.25 to 3.03% of total sequences, followed by sequences affiliated with Streptophyta (algae and vascular plants) 0.01-0.45% and Chlorophyta (green algae) 0.01-0.1%. Enrichment and cultivation approaches revealed that cyanobacteria and green algae survive in permafrost and they could be revived during prolonged incubation at low light intensity. Among photosynthetic microorganisms isolated from permafrost, the filamentous Oscillatoria-like cyanobacteria and unicellular green algae of the genus Chlorella were dominant. Our findings suggest that permafrost cyanobacteria and green algae are expected to be effective members of the re-assembled community after permafrost thawing and soil collapse.
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Affiliation(s)
- Tatiana A Vishnivetskaya
- Center for Environmental Biotechnology, University of Tennessee, 676 Dabney Hall, 1416 Circle Drive, Knoxville, TN 37996-1605, USA.,Soil Cryology Laboratory, Institute of Physicochemical and Biological Problems in Soil Science, Institutskaya Street, Bldg. 2, Pushchino, Russia
| | - Abraham L Almatari
- Center for Environmental Biotechnology, University of Tennessee, 676 Dabney Hall, 1416 Circle Drive, Knoxville, TN 37996-1605, USA
| | - Elena V Spirina
- Soil Cryology Laboratory, Institute of Physicochemical and Biological Problems in Soil Science, Institutskaya Street, Bldg. 2, Pushchino, Russia
| | - Xiaofen Wu
- Center for Environmental Biotechnology, University of Tennessee, 676 Dabney Hall, 1416 Circle Drive, Knoxville, TN 37996-1605, USA
| | - Daniel E Williams
- Center for Environmental Biotechnology, University of Tennessee, 676 Dabney Hall, 1416 Circle Drive, Knoxville, TN 37996-1605, USA
| | - Susan M Pfiffner
- Center for Environmental Biotechnology, University of Tennessee, 676 Dabney Hall, 1416 Circle Drive, Knoxville, TN 37996-1605, USA
| | - Elizaveta M Rivkina
- Soil Cryology Laboratory, Institute of Physicochemical and Biological Problems in Soil Science, Institutskaya Street, Bldg. 2, Pushchino, Russia
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22
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Kedem I, Milrad Y, Kaplan A, Yacoby I. Juggling Lightning: How Chlorella ohadii handles extreme energy inputs without damage. PHOTOSYNTHESIS RESEARCH 2021; 147:329-344. [PMID: 33389446 DOI: 10.1007/s11120-020-00809-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 12/03/2020] [Indexed: 06/12/2023]
Abstract
The green alga Chlorella ohadii was isolated from a desert biological soil crust, one of the harshest environments on Earth. When grown under optimal laboratory settings it shows the fastest growth rate ever reported for a photosynthetic eukaryote and a complete resistance to photodamage even under unnaturally high light intensities. Here we examined the energy distribution along the photosynthetic pathway under four light and carbon regimes. This was performed using various methodologies such as membrane inlet mass spectrometer with stable O2 isotopes, variable fluorescence, electrochromic shift and fluorescence assessment of NADPH level, as well as the use of specific inhibitors. We show that the preceding illumination and CO2 level during growth strongly affect the energy dissipation strategies employed by the cell. For example, plastid terminal oxidase (PTOX) plays an important role in energy dissipation, particularly in high light- and low-CO2-grown cells. Of particular note is the reliance on PSII cyclic electron flow as an effective and flexible dissipation mechanism in all conditions tested. The energy management observed here may be unique to C. ohadii, as it is the only known organism to cope with such conditions. However, the strategies demonstrated may provide an insight into the processes necessary for photosynthesis under high-light conditions.
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Affiliation(s)
- Isaac Kedem
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, 9190401, Jerusalem, Israel
| | - Yuval Milrad
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Aaron Kaplan
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, 9190401, Jerusalem, Israel.
| | - Iftach Yacoby
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
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23
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Girolomoni L, Bellamoli F, de la Cruz Valbuena G, Perozeni F, D'Andrea C, Cerullo G, Cazzaniga S, Ballottari M. Evolutionary divergence of photoprotection in the green algal lineage: a plant-like violaxanthin de-epoxidase enzyme activates the xanthophyll cycle in the green alga Chlorella vulgaris modulating photoprotection. THE NEW PHYTOLOGIST 2020; 228:136-150. [PMID: 32442330 PMCID: PMC7539987 DOI: 10.1111/nph.16674] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 05/13/2020] [Indexed: 05/05/2023]
Abstract
The xanthophyll cycle is the metabolic process by which the carotenoid violaxanthin is de-epoxidated to zeaxanthin, a xanthophyll with a crucial photoprotective role in higher plants and mosses. The role of zeaxanthin is still unclear in green algae, and a peculiar violaxanthin de-epoxidating enzyme was found in the model organism Chlamydomonas reinhardtii. Here, we investigated the molecular details and functions of the xanthophyll cycle in the case of Chlorella vulgaris, one of the green algae most considered for industrial cultivation, where resistance to high light stress is a prerequisite for sustainable biomass production. Identification of the violaxanthin de-epoxidase enzyme in C. vulgaris was performed by genome mining and in vitro analysis of the catalytic activity of the gene product identified. The photoprotective role of zeaxanthin was then investigated in vivo and in isolated pigment-binding complexes. The results obtained demonstrate the functioning, even though with a different pH sensitivity, of a plant-like violaxanthin de-epoxidase enzyme in C. vulgaris. Differently from C. reinhardtii, zeaxanthin accumulation in C. vulgaris was found to be crucial for photoprotective quenching of excitation energy harvested by both photosystem I and II. These findings demonstrate an evolutionary divergence of photoprotective mechanisms among Chlorophyta.
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Affiliation(s)
- Laura Girolomoni
- Department of BiotechnologyUniversity of VeronaStrada le Grazie 15Verona37134Italy
| | - Francesco Bellamoli
- Department of BiotechnologyUniversity of VeronaStrada le Grazie 15Verona37134Italy
| | | | - Federico Perozeni
- Department of BiotechnologyUniversity of VeronaStrada le Grazie 15Verona37134Italy
| | - Cosimo D'Andrea
- IFN‐CNRDepartment of PhysicsPolitecnico di MilanoPiazza Leonardo da Vinci 32Milan20133Italy
- Center for NanoScience and Technology @PoliMiIstituto Italiano di Tecnologiavia Pascoli 70/3Milan20133Italy
| | - Giulio Cerullo
- IFN‐CNRDepartment of PhysicsPolitecnico di MilanoPiazza Leonardo da Vinci 32Milan20133Italy
| | - Stefano Cazzaniga
- Department of BiotechnologyUniversity of VeronaStrada le Grazie 15Verona37134Italy
| | - Matteo Ballottari
- Department of BiotechnologyUniversity of VeronaStrada le Grazie 15Verona37134Italy
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Treves H, Siemiatkowska B, Luzarowska U, Murik O, Fernandez-Pozo N, Moraes TA, Erban A, Armbruster U, Brotman Y, Kopka J, Rensing SA, Szymanski J, Stitt M. Multi-omics reveals mechanisms of total resistance to extreme illumination of a desert alga. NATURE PLANTS 2020; 6:1031-1043. [PMID: 32719473 DOI: 10.1038/s41477-020-0729-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 06/24/2020] [Indexed: 05/25/2023]
Abstract
The unparalleled performance of Chlorella ohadii under irradiances of twice full sunlight underlines the gaps in our understanding of how the photosynthetic machinery operates, and what sets its upper functional limit. Rather than succumbing to photodamage under extreme irradiance, unique features of photosystem II function allow C. ohadii to maintain high rates of photosynthesis and growth, accompanied by major changes in composition and cellular structure. This remarkable resilience allowed us to investigate the systems response of photosynthesis and growth to extreme illumination in a metabolically active cell. Using redox proteomics, transcriptomics, metabolomics and lipidomics, we explored the cellular mechanisms that promote dissipation of excess redox energy, protein S-glutathionylation, inorganic carbon concentration, lipid and starch accumulation, and thylakoid stacking. C. ohadii possesses a readily available capacity to utilize a sudden excess of reducing power and carbon for growth and reserve formation, and post-translational redox regulation plays a pivotal role in this rapid response. Frequently the response in C. ohadii deviated from that of model species, reflecting its life history in desert sand crusts. Comparative global and case-specific analyses provided insights into the potential evolutionary role of effective reductant utilization in this extreme resistance of C. ohadii to extreme irradiation.
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Affiliation(s)
- Haim Treves
- Max Planck Institute for Molecular Plant Physiology, Potsdam, Germany.
| | | | | | - Omer Murik
- Department of Plant & Environmental Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Noe Fernandez-Pozo
- Plant Cell Biology, Department of Biology, University of Marburg, Marburg, Germany
| | | | - Alexander Erban
- Max Planck Institute for Molecular Plant Physiology, Potsdam, Germany
| | - Ute Armbruster
- Max Planck Institute for Molecular Plant Physiology, Potsdam, Germany
| | - Yariv Brotman
- Max Planck Institute for Molecular Plant Physiology, Potsdam, Germany
| | - Joachim Kopka
- Max Planck Institute for Molecular Plant Physiology, Potsdam, Germany
| | - Stefan Andreas Rensing
- Plant Cell Biology, Department of Biology, University of Marburg, Marburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Jedrzej Szymanski
- Department of Network Analysis and Modelling, IPK, Gatersleben, Germany
| | - Mark Stitt
- Max Planck Institute for Molecular Plant Physiology, Potsdam, Germany
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25
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Light absorption and scattering by high light-tolerant, fast-growing Chlorella vulgaris IPPAS C-1 cells. ALGAL RES 2020. [DOI: 10.1016/j.algal.2020.101881] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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26
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Sanz-Luque E, Bhaya D, Grossman AR. Polyphosphate: A Multifunctional Metabolite in Cyanobacteria and Algae. FRONTIERS IN PLANT SCIENCE 2020; 11:938. [PMID: 32670331 PMCID: PMC7332688 DOI: 10.3389/fpls.2020.00938] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 06/09/2020] [Indexed: 05/19/2023]
Abstract
Polyphosphate (polyP), a polymer of orthophosphate (PO4 3-) of varying lengths, has been identified in all kingdoms of life. It can serve as a source of chemical bond energy (phosphoanhydride bond) that may have been used by biological systems prior to the evolution of ATP. Intracellular polyP is mainly stored as granules in specific vacuoles called acidocalcisomes, and its synthesis and accumulation appear to impact a myriad of cellular functions. It serves as a reservoir for inorganic PO4 3- and an energy source for fueling cellular metabolism, participates in maintaining adenylate and metal cation homeostasis, functions as a scaffold for sequestering cations, exhibits chaperone function, covalently binds to proteins to modify their activity, and enables normal acclimation of cells to stress conditions. PolyP also appears to have a role in symbiotic and parasitic associations, and in higher eukaryotes, low polyP levels seem to impact cancerous proliferation, apoptosis, procoagulant and proinflammatory responses and cause defects in TOR signaling. In this review, we discuss the metabolism, storage, and function of polyP in photosynthetic microbes, which mostly includes research on green algae and cyanobacteria. We focus on factors that impact polyP synthesis, specific enzymes required for its synthesis and degradation, sequestration of polyP in acidocalcisomes, its role in cellular energetics, acclimation processes, and metal homeostasis, and then transition to its potential applications for bioremediation and medical purposes.
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Affiliation(s)
- Emanuel Sanz-Luque
- Department of Plant Biology, The Carnegie Institution for Science, Stanford, CA, United States
- Department of Biochemistry and Molecular Biology, University of Cordoba, Cordoba, Spain
| | - Devaki Bhaya
- Department of Plant Biology, The Carnegie Institution for Science, Stanford, CA, United States
| | - Arthur R. Grossman
- Department of Plant Biology, The Carnegie Institution for Science, Stanford, CA, United States
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28
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Malavasi V, Soru S, Cao G. Extremophile Microalgae: the potential for biotechnological application. JOURNAL OF PHYCOLOGY 2020; 56:559-573. [PMID: 31917871 DOI: 10.1111/jpy.12965] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 11/26/2019] [Indexed: 05/18/2023]
Abstract
Microalgae are photosynthetic microorganisms that use sunlight as an energy source, and convert water, carbon dioxide, and inorganic salts into algal biomass. The isolation and selection of microalgae, which allow one to obtain large amounts of biomass and valuable compounds, is a prerequisite for their successful industrial production. This work provides an overview of extremophile algae, where their ability to grow under harsh conditions and the corresponding accumulation of metabolites are addressed. Emphasis is placed on the high-value products of some prominent algae. Moreover, the most recent applications of these microorganisms and their potential exploitation in the context of astrobiology are taken into account.
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Affiliation(s)
- Veronica Malavasi
- Interdepartmental Center of Environmental Science and Engineering (CINSA), University of Cagliari, Via San Giorgio 12, 09124, Cagliari, Italy
| | - Santina Soru
- Interdepartmental Center of Environmental Science and Engineering (CINSA), University of Cagliari, Via San Giorgio 12, 09124, Cagliari, Italy
| | - Giacomo Cao
- Interdepartmental Center of Environmental Science and Engineering (CINSA), University of Cagliari, Via San Giorgio 12, 09124, Cagliari, Italy
- Department of Mechanical, Chemical and Materials Engineering, University of Cagliari, Via Marengo 2, 09123, Cagliari, Italy
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29
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Vecchi V, Barera S, Bassi R, Dall’Osto L. Potential and Challenges of Improving Photosynthesis in Algae. PLANTS 2020; 9:plants9010067. [PMID: 31947868 PMCID: PMC7020468 DOI: 10.3390/plants9010067] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 12/24/2019] [Accepted: 12/30/2019] [Indexed: 11/16/2022]
Abstract
Sunlight energy largely exceeds the energy required by anthropic activities, and therefore its exploitation represents a major target in the field of renewable energies. The interest in the mass cultivation of green microalgae has grown in the last decades, as algal biomass could be employed to cover a significant portion of global energy demand. Advantages of microalgal vs. plant biomass production include higher light-use efficiency, efficient carbon capture and the valorization of marginal lands and wastewaters. Realization of this potential requires a decrease of the current production costs, which can be obtained by increasing the productivity of the most common industrial strains, by the identification of factors limiting biomass yield, and by removing bottlenecks, namely through domestication strategies aimed to fill the gap between the theoretical and real productivity of algal cultures. In particular, the light-to-biomass conversion efficiency represents one of the major constraints for achieving a significant improvement of algal cell lines. This review outlines the molecular events of photosynthesis, which regulate the conversion of light into biomass, and discusses how these can be targeted to enhance productivity through mutagenesis, strain selection or genetic engineering. This review highlights the most recent results in the manipulation of the fundamental mechanisms of algal photosynthesis, which revealed that a significant yield enhancement is feasible. Moreover, metabolic engineering of microalgae, focused upon the development of renewable fuel biorefineries, has also drawn attention and resulted in efforts for enhancing productivity of oil or isoprenoids.
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Affiliation(s)
| | | | | | - Luca Dall’Osto
- Correspondence: ; Tel.: +39-045-8027806; Fax: +39-045-8027929
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30
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Abinandan S, Subashchandrabose SR, Venkateswarlu K, Megharaj M. Soil microalgae and cyanobacteria: the biotechnological potential in the maintenance of soil fertility and health. Crit Rev Biotechnol 2019; 39:981-998. [PMID: 31455102 DOI: 10.1080/07388551.2019.1654972] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The soil microbiota plays a major role in maintaining the nutrient balance, carbon sink, and soil health. Numerous studies reported on the function of microbiota such as plant growth-promoting bacteria and fungi in soil. Although microalgae and cyanobacteria are ubiquitous in soil, very less attention has been paid on the potential of these microorganisms. The indiscriminate use of various chemicals to enhance agricultural productivity led to serious consequences like structure instability, accumulation of toxic contaminants, etc., leading to an ecological imbalance between soil, plant, and microbiota. However, the significant role of microalgae and cyanobacteria in crop productivity and other potential options has been so far undermined. The intent of the present critical review is to highlight the significance of this unique group of microorganisms in terms of maintaining soil fertility and soil health. Beneficial soil ecological applications of these two groups in enhancing plant growth, establishing interrelationships among other microbes, and detoxifying chemical agents such as insecticides, herbicides, etc. through mutualistic cooperation by synthesizing enzymes and phytohormones are presented. Since recombinant technology involving genomic integration favors the development of useful traits in microalgae and cyanobacteria for their potential application in improvement of soil fertility and health, the merits and demerits of various such advanced methodologies associated in harnessing the biotechnological potential of these photosynthetic microorganisms for sustainable agriculture were also discussed.
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Affiliation(s)
- Sudharsanam Abinandan
- Global Centre for Environmental Remediation (GCER), Faculty of Science, University of Newcastle , Callaghan , Australia
| | - Suresh R Subashchandrabose
- Global Centre for Environmental Remediation (GCER), Faculty of Science, University of Newcastle , Callaghan , Australia.,Cooperative Research Centre for Contamination Assessment and Remediation of Environment (CRC CARE), University of Newcastle , Callaghan , Australia
| | | | - Mallavarapu Megharaj
- Global Centre for Environmental Remediation (GCER), Faculty of Science, University of Newcastle , Callaghan , Australia.,Cooperative Research Centre for Contamination Assessment and Remediation of Environment (CRC CARE), University of Newcastle , Callaghan , Australia
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31
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Havurinne V, Mattila H, Antinluoma M, Tyystjärvi E. Unresolved quenching mechanisms of chlorophyll fluorescence may invalidate MT saturating pulse analyses of photosynthetic electron transfer in microalgae. PHYSIOLOGIA PLANTARUM 2019; 166:365-379. [PMID: 30187483 DOI: 10.1111/ppl.12829] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 08/31/2018] [Accepted: 08/31/2018] [Indexed: 06/08/2023]
Abstract
Chlorophyll a fluorescence is a powerful tool for estimating photosynthetic efficiency, but there are still unanswered questions that hinder the use of its full potential. The present results describe a caveat in estimation of photosynthetic performance with so-called rapid light curves (RLCs) with pulse amplitude modulation fluorometers. RLCs of microalgae show a severe decrease in photosynthetic performance in high light, although a similar decrease cannot be seen with other methods. We show that this decrease cannot be assigned to energy-dependent non-photochemical quenching or photoinhibition or to the geometry of the algal sample. The measured decrease in electron transfer rate is small in the tested siphonaceuous algae and higher plants, but very notable in all planktonic species, exhibiting species-dependent variation in extent and reversibility. We performed in-depth analysis of the phenomenon in the diatom Phaeodactylum tricornutum, in which the decrease is the most pronounced and reversible among the tested organisms. The results suggest that quenching of fluorescence by oxidized plastoquinone alone cannot explain the phenomenon, and alternative quenching mechanisms within PSII need to be considered.
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Affiliation(s)
- Vesa Havurinne
- Department of Biochemistry/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Heta Mattila
- Department of Biochemistry/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Mikko Antinluoma
- Department of Biochemistry/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Esa Tyystjärvi
- Department of Biochemistry/Molecular Plant Biology, University of Turku, Turku, Finland
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Abstract
Over 100 whole-genome sequences from algae are published or soon to be published. The rapidly increasing availability of these fundamental resources is changing how we understand one of the most diverse, complex, and understudied groups of photosynthetic eukaryotes. Genome sequences provide a window into the functional potential of individual algae, with phylogenomics and functional genomics as tools for contextualizing and transferring knowledge from reference organisms into less well-characterized systems. Remarkably, over half of the proteins encoded by algal genomes are of unknown function, highlighting the volume of functional capabilities yet to be discovered. In this review, we provide an overview of publicly available algal genomes, their associated protein inventories, and their quality, with a summary of the statuses of protein function understanding and predictions.
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Affiliation(s)
| | - Sabeeha S Merchant
- Departments of Plant and Microbial Biology and Molecular and Cell Biology, University of California, Berkeley, California 94720, USA
- Institute for Genomics and Proteomics, University of California, Los Angeles, California 90095, USA
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Abstract
Photosynthesis and nitrogen fixation became evolutionarily immutable as “frozen metabolic accidents” because multiple interactions between the proteins and protein complexes involved led to their co-evolution in modules. This has impeded their adaptation to an oxidizing atmosphere, and reconfiguration now requires modification or replacement of whole modules, using either natural modules from exotic species or non-natural proteins with similar interaction potential. Ultimately, the relevant complexes might be reconstructed (almost) from scratch, starting either from appropriate precursor processes or by designing alternative pathways. These approaches will require advances in synthetic biology, laboratory evolution, and a better understanding of module functions.
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Affiliation(s)
- Dario Leister
- Faculty of Biology, Ludwig-Maximilians-University Munich, Großhaderner Str. 2, 82152, Planegg-Martinsried, Germany.
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Saber AA, Fučíková K, McManus HA, Guella G, Cantonati M. Novel green algal isolates from the Egyptian hyper-arid desert oases: a polyphasic approach with a description of Pharao desertorum gen. et sp. nov. (Chlorophyceae, Chlorophyta). JOURNAL OF PHYCOLOGY 2018; 54:342-357. [PMID: 29603234 DOI: 10.1111/jpy.12645] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 02/20/2018] [Indexed: 06/08/2023]
Abstract
The biodiversity of terrestrial algae is still grossly understudied, and African deserts in particular are barely touched in this respect. Here, four coccoid green algae from oases in the Western Desert of Egypt were characterized using a combination of morphotaxonomic, ecological and 18S rDNA data, with additional carotenoid and lipid analyses for two of the strains. Three strains were identified as affiliated with known taxa: Mychonastes sp., Asterarcys sp. (first report of this genus from a desert soil), and Stichococcus cf. deasonii. The fourth strain is proposed to represent a new cryptic genus Pharao gen. nov., with the type species P. desertorum sp. nov. The new taxon is sister to the clade of uncharacterized North American desert strains of Radiococcaceae (Chlorophyceae, Chlorophyta). The pigment profile of P. desertorum gen. et sp. nov. revealed carotenoids and chlorophylls typical of green algae. Bioorganic analysis showed a complex lipidome based on phospho- (PC), galacto- (MGDG and DGDG), betaine- (DGTS), and sulfoquinovosyl- (SQDG) membrane lipids, besides significant amounts of storage neutral lipids such as diacyl- (DAG) and triacylglycerols (TAG). The presence of saturated alkyl chains within all the membrane lipid classes in P. desertorum and Asterarcys sp. appears to reflect the need to maintain membrane fluidity and viscosity. In summary, African deserts likely still harbor new taxa to be described, and lipidomic analyses of such taxa may provide clues about their ability to survive in the extremely harsh desert habitats.
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Affiliation(s)
- Abdullah A Saber
- Botany Department, Faculty of Science, Ain Shams University, Abbassia Square-11566, Cairo, Egypt
| | - Karolina Fučíková
- Department of Natural Sciences, Assumption College, 500 Salisbury St., Worcester, Massachusetts, USA
| | - Hilary A McManus
- Department of Biological and Environmental Sciences, Le Moyne College, Syracuse, New York, USA
| | - Graziano Guella
- Department of Physics, Bioorganic Chemistry Lab, University of Trento, Via Sommarive 14, Povo, 38123, Trentino, Italy
- CNR, Institute of Biophysics, Via alla Cascata 56/C, Povo, 38123, Trento, Italy
- Center for Agriculture, Food and the Environment, University of Trento, San Michele all'Adige, Italy
| | - Marco Cantonati
- Museo delle Scienze - MUSE, Limnology and Phycology Section, Corso del Lavoro e della Scienza 3, I-38123, Trento, Italy
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35
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Berthelier J, Casse N, Daccord N, Jamilloux V, Saint-Jean B, Carrier G. A transposable element annotation pipeline and expression analysis reveal potentially active elements in the microalga Tisochrysis lutea. BMC Genomics 2018. [PMID: 29783941 DOI: 10.17882/52231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023] Open
Abstract
BACKGROUND Transposable elements (TEs) are mobile DNA sequences known as drivers of genome evolution. Their impacts have been widely studied in animals, plants and insects, but little is known about them in microalgae. In a previous study, we compared the genetic polymorphisms between strains of the haptophyte microalga Tisochrysis lutea and suggested the involvement of active autonomous TEs in their genome evolution. RESULTS To identify potentially autonomous TEs, we designed a pipeline named PiRATE (Pipeline to Retrieve and Annotate Transposable Elements, download: https://doi.org/10.17882/51795 ), and conducted an accurate TE annotation on a new genome assembly of T. lutea. PiRATE is composed of detection, classification and annotation steps. Its detection step combines multiple, existing analysis packages representing all major approaches for TE detection and its classification step was optimized for microalgal genomes. The efficiency of the detection and classification steps was evaluated with data on the model species Arabidopsis thaliana. PiRATE detected 81% of the TE families of A. thaliana and correctly classified 75% of them. We applied PiRATE to T. lutea genomic data and established that its genome contains 15.89% Class I and 4.95% Class II TEs. In these, 3.79 and 17.05% correspond to potentially autonomous and non-autonomous TEs, respectively. Annotation data was combined with transcriptomic and proteomic data to identify potentially active autonomous TEs. We identified 17 expressed TE families and, among these, a TIR/Mariner and a TIR/hAT family were able to synthesize their transposase. Both these TE families were among the three highest expressed genes in a previous transcriptomic study and are composed of highly similar copies throughout the genome of T. lutea. This sum of evidence reveals that both these TE families could be capable of transposing or triggering the transposition of potential related MITE elements. CONCLUSION This manuscript provides an example of a de novo transposable element annotation of a non-model organism characterized by a fragmented genome assembly and belonging to a poorly studied phylum at genomic level. Integration of multi-omics data enabled the discovery of potential mobile TEs and opens the way for new discoveries on the role of these repeated elements in genomic evolution of microalgae.
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Affiliation(s)
- Jérémy Berthelier
- IFREMER, Physiology and Biotechnology of Algae Laboratory, rue de l'Ile d'Yeu, 44311, Nantes, France.
- Mer Molécules Santé, EA 2160 IUML - FR 3473 CNRS, Le Mans University, Le Mans, France.
| | - Nathalie Casse
- Mer Molécules Santé, EA 2160 IUML - FR 3473 CNRS, Le Mans University, Le Mans, France
| | - Nicolas Daccord
- Institut de Recherche en Horticulture et Semences, INRA of Angers, AGROCAMPUS-Ouest, SFR4207 QUASAV, Université d'Angers, Angers, France
- Université Bretagne Loire, Angers, France
| | | | - Bruno Saint-Jean
- IFREMER, Physiology and Biotechnology of Algae Laboratory, rue de l'Ile d'Yeu, 44311, Nantes, France
| | - Grégory Carrier
- IFREMER, Physiology and Biotechnology of Algae Laboratory, rue de l'Ile d'Yeu, 44311, Nantes, France
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36
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Berthelier J, Casse N, Daccord N, Jamilloux V, Saint-Jean B, Carrier G. A transposable element annotation pipeline and expression analysis reveal potentially active elements in the microalga Tisochrysis lutea. BMC Genomics 2018; 19:378. [PMID: 29783941 PMCID: PMC5963040 DOI: 10.1186/s12864-018-4763-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 05/07/2018] [Indexed: 01/01/2023] Open
Abstract
Background Transposable elements (TEs) are mobile DNA sequences known as drivers of genome evolution. Their impacts have been widely studied in animals, plants and insects, but little is known about them in microalgae. In a previous study, we compared the genetic polymorphisms between strains of the haptophyte microalga Tisochrysis lutea and suggested the involvement of active autonomous TEs in their genome evolution. Results To identify potentially autonomous TEs, we designed a pipeline named PiRATE (Pipeline to Retrieve and Annotate Transposable Elements, download: 10.17882/51795), and conducted an accurate TE annotation on a new genome assembly of T. lutea. PiRATE is composed of detection, classification and annotation steps. Its detection step combines multiple, existing analysis packages representing all major approaches for TE detection and its classification step was optimized for microalgal genomes. The efficiency of the detection and classification steps was evaluated with data on the model species Arabidopsis thaliana. PiRATE detected 81% of the TE families of A. thaliana and correctly classified 75% of them. We applied PiRATE to T. lutea genomic data and established that its genome contains 15.89% Class I and 4.95% Class II TEs. In these, 3.79 and 17.05% correspond to potentially autonomous and non-autonomous TEs, respectively. Annotation data was combined with transcriptomic and proteomic data to identify potentially active autonomous TEs. We identified 17 expressed TE families and, among these, a TIR/Mariner and a TIR/hAT family were able to synthesize their transposase. Both these TE families were among the three highest expressed genes in a previous transcriptomic study and are composed of highly similar copies throughout the genome of T. lutea. This sum of evidence reveals that both these TE families could be capable of transposing or triggering the transposition of potential related MITE elements. Conclusion This manuscript provides an example of a de novo transposable element annotation of a non-model organism characterized by a fragmented genome assembly and belonging to a poorly studied phylum at genomic level. Integration of multi-omics data enabled the discovery of potential mobile TEs and opens the way for new discoveries on the role of these repeated elements in genomic evolution of microalgae. Electronic supplementary material The online version of this article (10.1186/s12864-018-4763-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jérémy Berthelier
- IFREMER, Physiology and Biotechnology of Algae Laboratory, rue de l'Ile d'Yeu, 44311, Nantes, France. .,Mer Molécules Santé, EA 2160 IUML - FR 3473 CNRS, Le Mans University, Le Mans, France.
| | - Nathalie Casse
- Mer Molécules Santé, EA 2160 IUML - FR 3473 CNRS, Le Mans University, Le Mans, France
| | - Nicolas Daccord
- Institut de Recherche en Horticulture et Semences, INRA of Angers, AGROCAMPUS-Ouest, SFR4207 QUASAV, Université d'Angers, Angers, France.,Université Bretagne Loire, Angers, France
| | | | - Bruno Saint-Jean
- IFREMER, Physiology and Biotechnology of Algae Laboratory, rue de l'Ile d'Yeu, 44311, Nantes, France
| | - Grégory Carrier
- IFREMER, Physiology and Biotechnology of Algae Laboratory, rue de l'Ile d'Yeu, 44311, Nantes, France
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Pierangelini M, Ryšánek D, Lang I, Adlassnig W, Holzinger A. Terrestrial adaptation of green algae Klebsormidium and Zygnema (Charophyta) involves diversity in photosynthetic traits but not in CO 2 acquisition. PLANTA 2017; 246:971-986. [PMID: 28721563 PMCID: PMC5633629 DOI: 10.1007/s00425-017-2741-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 07/09/2017] [Indexed: 05/20/2023]
Abstract
The basal streptophyte Klebsormidium and the advanced Zygnema show adaptation to terrestrialization. Differences are found in photoprotection and resistance to short-term light changes, but not in CO 2 acquisition. Streptophyte green algae colonized land about 450-500 million years ago giving origin to terrestrial plants. We aim to understand how their physiological adaptations are linked to the ecological conditions (light, water and CO2) characterizing modern terrestrial habitats. A new Klebsormidium isolate from a strongly acidic environment of a former copper mine (Schwarzwand, Austria) is investigated, in comparison to Klebsormidium cf. flaccidum and Zygnema sp. We show that these genera possess different photosynthetic traits and water requirements. Particularly, the Klebsormidium species displayed a higher photoprotection capacity, concluded from non-photochemical quenching (NPQ) and higher tolerance to high light intensity than Zygnema. However, Klebsormidium suffered from photoinhibition when the light intensity in the environment increased rapidly, indicating that NPQ is involved in photoprotection against strong and stable irradiance. Klebsormidium was also highly resistant to cellular water loss (dehydration) under low light. On the other hand, exposure to relatively high light intensity during dehydration caused a harmful over-reduction of the electron transport chain, leading to PSII damages and impairing the ability to recover after rehydration. Thus, we suggest that dehydration is a selective force shaping the adaptation of this species towards low light. Contrary to the photosynthetic characteristics, the inorganic carbon (C i ) acquisition was equivalent between Klebsormidium and Zygnema. Despite their different habitats and restriction to hydro-terrestrial environment, the three organisms showed similar use of CO2 and HCO3- as source of Ci for photosynthesis, pointing out a similar adaptation of their CO2-concentrating mechanisms to terrestrial life.
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Affiliation(s)
- Mattia Pierangelini
- Department of Botany, Functional Plant Biology, University of Innsbruck, 6020, Innsbruck, Austria
| | - David Ryšánek
- Department of Botany, Faculty of Science, Charles University in Prague, Benátská 2, 12801, Prague 2, Czech Republic
- Laboratory of Environmental Microbiology, Institute of Microbiology of the CAS, v. v. i., Průmyslová 595, 252 42, Vestec, Czech Republic
| | - Ingeborg Lang
- Faculty of Life Sciences, Core Facility Cell Imaging and Ultrastructure Research, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Wolfram Adlassnig
- Faculty of Life Sciences, Core Facility Cell Imaging and Ultrastructure Research, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Andreas Holzinger
- Department of Botany, Functional Plant Biology, University of Innsbruck, 6020, Innsbruck, Austria.
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Bayro-Kaiser V, Nelson N. Microalgal hydrogen production: prospects of an essential technology for a clean and sustainable energy economy. PHOTOSYNTHESIS RESEARCH 2017; 133:49-62. [PMID: 28239761 PMCID: PMC5500669 DOI: 10.1007/s11120-017-0350-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 02/06/2017] [Indexed: 05/17/2023]
Abstract
Modern energy production is required to undergo a dramatic transformation. It will have to replace fossil fuel use by a sustainable and clean energy economy while meeting the growing world energy needs. This review analyzes the current energy sector, available energy sources, and energy conversion technologies. Solar energy is the only energy source with the potential to fully replace fossil fuels, and hydrogen is a crucial energy carrier for ensuring energy availability across the globe. The importance of photosynthetic hydrogen production for a solar-powered hydrogen economy is highlighted and the development and potential of this technology are discussed. Much successful research for improved photosynthetic hydrogen production under laboratory conditions has been reported, and attempts are underway to develop upscale systems. We suggest that a process of integrating these achievements into one system to strive for efficient sustainable energy conversion is already justified. Pursuing this goal may lead to a mature technology for industrial deployment.
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Affiliation(s)
- Vinzenz Bayro-Kaiser
- Department of Biochemistry and Molecular Biology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, 69978, Tel Aviv, Israel.
| | - Nathan Nelson
- Department of Biochemistry and Molecular Biology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, 69978, Tel Aviv, Israel
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Metabolic Flexibility Underpins Growth Capabilities of the Fastest Growing Alga. Curr Biol 2017; 27:2559-2567.e3. [PMID: 28803869 DOI: 10.1016/j.cub.2017.07.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 07/02/2017] [Accepted: 07/06/2017] [Indexed: 11/21/2022]
Abstract
The factors rate-limiting growth of photosynthetic organisms under optimal conditions are controversial [1-8]. Adaptation to extreme environments is usually accompanied by reduced performance under optimal conditions [9, 10]. However, the green alga Chlorella ohadii, isolated from a harsh desert biological soil crust [11-17], does not obey this rule. In addition to resistance to photodamage [17, 18], it performs the fastest growth ever reported for photosynthetic eukaryotes. A multiphasic growth pattern (very fast growth [phase I], followed by growth retardation [phase II] and additional fast growth [phase III]) observed under constant illumination and temperature indicates synchronization of the algal population. Large physiological changes at transitions between growth phases suggest metabolic shifts. Indeed, metabolome analyses at points along the growth phases revealed large changes in the levels of many metabolites during growth with an overall rise during phase I and decline in phase II. Multivariate analysis of the metabolome data highlighted growth phase as the main factor contributing to observed metabolite variance. The analyses identified putrescine as the strongest predictive metabolite for growth phase and a putative growth regulator. Indeed, extracellular additions of polyamines strongly affected the growth rate in phase I and the growth arrest in phase II, with a marked effect on O2 exchange. Our data implicate polyamines as the signals harmonizing metabolic shifts and suggest that metabolic flexibility enables the immense growth capabilities of C. ohadii. The data provide a new dimension to current models focusing on growth-limiting processes in photosynthetic organisms where the anabolic and catabolic metabolisms must be strictly regulated.
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Photosystem II-cyclic electron flow powers exceptional photoprotection and record growth in the microalga Chlorella ohadii. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:873-883. [PMID: 28734933 DOI: 10.1016/j.bbabio.2017.07.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 07/12/2017] [Accepted: 07/14/2017] [Indexed: 01/13/2023]
Abstract
The desert microalga Chlorella ohadii was reported to grow at extreme light intensities with minimal photoinhibition, tolerate frequent de/re-hydrations, yet minimally employs antenna-based non-photochemical quenching for photoprotection. Here we investigate the molecular mechanisms by measuring Photosystem II charge separation yield (chlorophyll variable fluorescence, Fv/Fm) and flash-induced O2 yield to measure the contributions from both linear (PSII-LEF) and cyclic (PSII-CEF) electron flow within PSII. Cells grow increasingly faster at higher light intensities (μE/m2/s) from low (20) to high (200) to extreme (2000) by escalating photoprotection via shifting from PSII-LEF to PSII-CEF. This shifts PSII charge separation from plastoquinone reduction (PSII-LEF) to plastoquinol oxidation (PSII-CEF), here postulated to enable proton gradient and ATP generation that powers photoprotection. Low light-grown cells have unusually small antennae (332 Chl/PSII), use mainly PSII-LEF (95%) and convert 40% of PSII charge separations into O2 (a high O2 quantum yield of 0.06mol/mol PSII/flash). High light-grown cells have smaller antenna and lower PSII-LEF (63%). Extreme light-grown cells have only 42 Chl/PSII (no LHCII antenna), minimal PSII-LEF (10%), and grow faster than any known phototroph (doubling time 1.3h). Adding a synthetic quinone in excess to supplement the PQ pool fully uncouples PSII-CEF from its natural regulation and produces maximum PSII-LEF. Upon dark adaptation PSII-LEF rapidly reverts to PSII-CEF, a transient protection mechanism to conserve water and minimize the cost of antenna biosynthesis. The capacity of the electron acceptor pool (plastoquinone pool), and the characteristic times for exchange of (PQH2)B with PQpool and reoxidation of (PQH2)pool were determined.
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The drug ornidazole inhibits photosynthesis in a different mechanism described for protozoa and anaerobic bacteria. Biochem J 2016; 473:4413-4426. [DOI: 10.1042/bcj20160433] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 09/01/2016] [Accepted: 09/19/2016] [Indexed: 11/17/2022]
Abstract
Ornidazole of the 5-nitroimidazole drug family is used to treat protozoan and anaerobic bacterial infections via a mechanism that involves preactivation by reduction of the nitro group, and production of toxic derivatives and radicals. Metronidazole, another drug family member, has been suggested to affect photosynthesis by draining electrons from the electron carrier ferredoxin, thus inhibiting NADP+ reduction and stimulating radical and peroxide production. Here we show, however, that ornidazole inhibits photosynthesis via a different mechanism. While having a minute effect on the photosynthetic electron transport and oxygen photoreduction, ornidazole hinders the activity of two Calvin cycle enzymes, triose-phosphate isomerase (TPI) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Modeling of ornidazole's interaction with ferredoxin of the protozoan Trichomonas suggests efficient electron tunneling from the iron–sulfur cluster to the nitro group of the drug. A similar docking site of ornidazole at the plant-type ferredoxin does not exist, and the best simulated alternative does not support such efficient tunneling. Notably, TPI was inhibited by ornidazole in the dark or when electron transport was blocked by dichloromethyl diphenylurea, indicating that this inhibition was unrelated to the electron transport machinery. Although TPI and GAPDH isoenzymes are involved in glycolysis and gluconeogenesis, ornidazole's effect on respiration of photoautotrophs is moderate, thus raising its value as an efficient inhibitor of photosynthesis. The scarcity of Calvin cycle inhibitors capable of penetrating cell membranes emphasizes on the value of ornidazole for studying the regulation of this cycle.
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Brinkert K, Le Formal F, Li X, Durrant J, Rutherford AW, Fantuzzi A. Photocurrents from photosystem II in a metal oxide hybrid system: Electron transfer pathways. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1857:1497-1505. [PMID: 26946088 PMCID: PMC4990130 DOI: 10.1016/j.bbabio.2016.03.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 02/19/2016] [Accepted: 03/01/2016] [Indexed: 12/21/2022]
Abstract
We have investigated the nature of the photocurrent generated by Photosystem II (PSII), the water oxidizing enzyme, isolated from Thermosynechococcus elongatus, when immobilized on nanostructured titanium dioxide on an indium tin oxide electrode (TiO2/ITO). We investigated the properties of the photocurrent from PSII when immobilized as a monolayer versus multilayers, in the presence and absence of an inhibitor that binds to the site of the exchangeable quinone (QB) and in the presence and absence of exogenous mobile electron carriers (mediators). The findings indicate that electron transfer occurs from the first quinone (QA) directly to the electrode surface but that the electron transfer through the nanostructured metal oxide is the rate-limiting step. Redox mediators enhance the photocurrent by taking electrons from the nanostructured semiconductor surface to the ITO electrode surface not from PSII. This is demonstrated by photocurrent enhancement using a mediator incapable of accepting electrons from PSII. This model for electron transfer also explains anomalies reported in the literature using similar and related systems. The slow rate of the electron transfer step in the TiO2 is due to the energy level of electron injection into the semiconducting material being below the conduction band. This limits the usefulness of the present hybrid electrode. Strategies to overcome this kinetic limitation are discussed.
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Affiliation(s)
- Katharina Brinkert
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Florian Le Formal
- Department of Chemistry, Imperial College London, London SW7 2AZ, UK
| | - Xiaoe Li
- Department of Chemistry, Imperial College London, London SW7 2AZ, UK
| | - James Durrant
- Department of Chemistry, Imperial College London, London SW7 2AZ, UK
| | | | - Andrea Fantuzzi
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK.
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Treves H, Raanan H, Kedem I, Murik O, Keren N, Zer H, Berkowicz SM, Giordano M, Norici A, Shotland Y, Ohad I, Kaplan A. The mechanisms whereby the green alga Chlorella ohadii, isolated from desert soil crust, exhibits unparalleled photodamage resistance. THE NEW PHYTOLOGIST 2016; 210:1229-43. [PMID: 26853530 DOI: 10.1111/nph.13870] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 12/16/2015] [Indexed: 05/24/2023]
Abstract
Excess illumination damages the photosynthetic apparatus with severe implications with regard to plant productivity. Unlike model organisms, the growth of Chlorella ohadii, isolated from desert soil crust, remains unchanged and photosynthetic O2 evolution increases, even when exposed to irradiation twice that of maximal sunlight. Spectroscopic, biochemical and molecular approaches were applied to uncover the mechanisms involved. D1 protein in photosystem II (PSII) is barely degraded, even when exposed to antibiotics that prevent its replenishment. Measurements of various PSII parameters indicate that this complex functions differently from that in model organisms and suggest that C. ohadii activates a nonradiative electron recombination route which minimizes singlet oxygen formation and the resulting photoinhibition. The light-harvesting antenna is very small and carotene composition is hardly affected by excess illumination. Instead of succumbing to photodamage, C. ohadii activates additional means to dissipate excess light energy. It undergoes major structural, compositional and physiological changes, leading to a large rise in photosynthetic rate, lipids and carbohydrate content and inorganic carbon cycling. The ability of C. ohadii to avoid photodamage relies on a modified function of PSII and the dissipation of excess reductants downstream of the photosynthetic reaction centers. The biotechnological potential as a gene source for crop plant improvement is self-evident.
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Affiliation(s)
- Haim Treves
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Hagai Raanan
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Isaac Kedem
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Omer Murik
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Nir Keren
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Hagit Zer
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Simon M Berkowicz
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Mario Giordano
- Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, Ancona, 60131, Italy
| | - Alessandra Norici
- Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, Ancona, 60131, Italy
| | - Yoram Shotland
- Department of Chemical Engineering, Shamoon College of Engineering, Beer Sheva, 84100, Israel
| | - Itzhak Ohad
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Aaron Kaplan
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
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Guéra A, Gasulla F, Barreno E. Formation of photosystem II reaction centers that work as energy sinks in lichen symbiotic Trebouxiophyceae microalgae. PHOTOSYNTHESIS RESEARCH 2016; 128:15-33. [PMID: 26482588 DOI: 10.1007/s11120-015-0196-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 10/08/2015] [Indexed: 06/05/2023]
Abstract
Lichens are poikilohydric symbiotic organisms that can survive in the absence of water. Photosynthesis must be highly regulated in these organisms, which live under continuous desiccation-rehydration cycles, to avoid photooxidative damage. Analysis of chlorophyll a fluorescence induction curves in the lichen microalgae of the Trebouxiophyceae Asterochloris erici and in Trebouxia jamesii (TR1) and Trebouxia sp. (TR9) phycobionts, isolated from the lichen Ramalina farinacea, shows differences with higher plants. In the presence of the photosynthetic electron transport inhibitor DCMU, the kinetics of Q(A) reduction is related to variable fluorescence by a sigmoidal function that approaches a horizontal asymptote. An excellent fit to these curves was obtained by applying a model based on the following assumptions: (1) after closure, the reaction centers (RCs) can be converted into "energy sink" centers (sRCs); (2) the probability of energy leaving the sRCs is very low or zero and (3) energy is not transferred from the antenna of PSII units with sRCs to other PSII units. The formation of sRCs units is also induced by repetitive light saturating pulses or at the transition from dark to light and probably requires the accumulation of reduced Q(A), as well as structural changes in the reaction centers of PSII. This type of energy sink would provide a very efficient way to protect symbiotic microalgae against abrupt changes in light intensity.
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Affiliation(s)
- Alfredo Guéra
- Departamento de Ciencias de la Vida, Universidad de Alcalá, Edificio de Ciencias, Campus externo, 28871, Alcalá de Henares, Madrid, Spain.
| | - Francisco Gasulla
- Departamento de Ciencias de la Vida, Universidad de Alcalá, Edificio de Ciencias, Campus externo, 28871, Alcalá de Henares, Madrid, Spain
- Botánica, ICBIBE, Facultad de Ciencias Biológicas, Universitat de València, C/Dr. Moliner 50, 46100, Burjassot, Valencia, Spain
| | - Eva Barreno
- Botánica, ICBIBE, Facultad de Ciencias Biológicas, Universitat de València, C/Dr. Moliner 50, 46100, Burjassot, Valencia, Spain
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Xie X, Huang A, Gu W, Zang Z, Pan G, Gao S, He L, Zhang B, Niu J, Lin A, Wang G. Photorespiration participates in the assimilation of acetate in Chlorella sorokiniana under high light. THE NEW PHYTOLOGIST 2016; 209:987-998. [PMID: 26439434 DOI: 10.1111/nph.13659] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 08/17/2015] [Indexed: 06/05/2023]
Abstract
The development of microalgae on an industrial scale largely depends on the economic feasibility of mass production. High light induces productive suspensions during cultivation in a tubular photobioreactor. Herein, we report that high light, which inhibited the growth of Chlorella sorokiniana under autotrophic conditions, enhanced the growth of this alga in the presence of acetate. We compared pigments, proteomics and the metabolic flux ratio in C. sorokiniana cultivated under high light (HL) and under low light (LL) in the presence of acetate. Our results showed that high light induced the synthesis of xanthophyll and suppressed the synthesis of chlorophylls. Acetate in the medium was exhausted much more rapidly in HL than in LL. The data obtained from LC-MS/MS indicated that high light enhanced photorespiration, the Calvin cycle and the glyoxylate cycle of mixotrophic C. sorokiniana. The results of metabolic flux ratio analysis showed that the majority of the assimilated carbon derived from supplemented acetate, and photorespiratory glyoxylate could enter the glyoxylate cycle. Based on these data, we conclude that photorespiration provides glyoxylate to speed up the glyoxylate cycle, and releases acetate-derived CO2 for the Calvin cycle. Thus, photorespiration connects the glyoxylate cycle and the Calvin cycle, and participates in the assimilation of supplemented acetate in C. sorokiniana under high light.
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Affiliation(s)
- Xiujun Xie
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China
- Tianjin Key Laboratory of Marine Resources and Chemistry, College of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Aiyou Huang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China
| | - Wenhui Gu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China
| | - Zhengrong Zang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Guanghua Pan
- Tianjin Key Laboratory of Marine Resources and Chemistry, College of Marine Science and Engineering, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Shan Gao
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China
| | - Linwen He
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China
| | - Baoyu Zhang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China
| | - Jianfeng Niu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China
| | - Apeng Lin
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China
| | - Guangce Wang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China
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Varshney P, Mikulic P, Vonshak A, Beardall J, Wangikar PP. Extremophilic micro-algae and their potential contribution in biotechnology. BIORESOURCE TECHNOLOGY 2015; 184:363-372. [PMID: 25443670 DOI: 10.1016/j.biortech.2014.11.040] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Revised: 11/05/2014] [Accepted: 11/07/2014] [Indexed: 05/18/2023]
Abstract
Micro-algae have potential as sustainable sources of energy and products and alternative mode of agriculture. However, their mass cultivation is challenging due to low survival under harsh outdoor conditions and competition from other, undesired, species. Extremophilic micro-algae have a role to play by virtue of their ability to grow under acidic or alkaline pH, high temperature, light, CO2 level and metal concentration. In this review, we provide several examples of potential biotechnological applications of extremophilic micro-algae and the ranges of tolerated extremes. We also discuss the adaptive mechanisms of tolerance to these extremes. Analysis of phylogenetic relationship of the reported extremophiles suggests certain groups of the Kingdom Protista to be more tolerant to extremophilic conditions than other taxa. While extremophilic microalgae are beginning to be explored, much needs to be done in terms of the physiology, molecular biology, metabolic engineering and outdoor cultivation trials before their true potential is realized.
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Affiliation(s)
- Prachi Varshney
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India; School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia; IIT Bombay Monash Research Academy, CSE Building, 2nd Floor, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Paulina Mikulic
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Avigad Vonshak
- Jacob Blaustein Institutes for Desert Research, Ben Gurion University, Sede Boqer Campus, 84990, Israel
| | - John Beardall
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Pramod P Wangikar
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
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Raanan H, Felde VJMNL, Peth S, Drahorad S, Ionescu D, Eshkol G, Treves H, Felix-Henningsen P, Berkowicz SM, Keren N, Horn R, Hagemann M, Kaplan A. Three-dimensional structure and cyanobacterial activity within a desert biological soil crust. Environ Microbiol 2015; 18:372-83. [DOI: 10.1111/1462-2920.12859] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 02/26/2015] [Accepted: 03/06/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Hagai Raanan
- Department of Plant and Environmental Sciences; Edmond J. Safra Campus, Givat Ram; The Hebrew University of Jerusalem; Jerusalem 9190401 Israel
| | - Vincent J. M. N. L. Felde
- Institute of Soil Science and Soil Conservation; Justus Liebig University Giessen; 35392 Giessen Germany
| | - Stephan Peth
- Deparment of Soil Science; Faculty of Ecological Agriculture; University of Kassel; 37213 Witzenhausen Germany
| | - Sylvie Drahorad
- Institute of Soil Science and Soil Conservation; Justus Liebig University Giessen; 35392 Giessen Germany
| | - Danny Ionescu
- The Max Planck Institute for Marine Microbiology; Celsius Str. 1 28359 Bremen Germany
| | - Gil Eshkol
- Department of Plant and Environmental Sciences; Edmond J. Safra Campus, Givat Ram; The Hebrew University of Jerusalem; Jerusalem 9190401 Israel
| | - Haim Treves
- Department of Plant and Environmental Sciences; Edmond J. Safra Campus, Givat Ram; The Hebrew University of Jerusalem; Jerusalem 9190401 Israel
| | - Peter Felix-Henningsen
- Institute of Soil Science and Soil Conservation; Justus Liebig University Giessen; 35392 Giessen Germany
| | - Simon M. Berkowicz
- Department of Plant and Environmental Sciences; Edmond J. Safra Campus, Givat Ram; The Hebrew University of Jerusalem; Jerusalem 9190401 Israel
- Arid Ecosystems Research Center; Edmond J. Safra Campus, Givat Ram; The Hebrew University of Jerusalem; Jerusalem 9190401 Israel
| | - Nir Keren
- Department of Plant and Environmental Sciences; Edmond J. Safra Campus, Givat Ram; The Hebrew University of Jerusalem; Jerusalem 9190401 Israel
| | - Rainer Horn
- Institute of Plant Nutrition and Soil Science; Christian Albrechts University of Kiel; 24118 Kiel Germany
| | - Martin Hagemann
- Institut für Biowissenschaften; Universität Rostock; D-18059 Rostock Germany
| | - Aaron Kaplan
- Department of Plant and Environmental Sciences; Edmond J. Safra Campus, Givat Ram; The Hebrew University of Jerusalem; Jerusalem 9190401 Israel
- Arid Ecosystems Research Center; Edmond J. Safra Campus, Givat Ram; The Hebrew University of Jerusalem; Jerusalem 9190401 Israel
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