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Grettenberger CL, Abou‐Shanab R, Hamilton TL. Limiting factors in the operation of photosystems I and II in cyanobacteria. Microb Biotechnol 2024; 17:e14519. [PMID: 39101352 PMCID: PMC11298993 DOI: 10.1111/1751-7915.14519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 06/16/2024] [Indexed: 08/06/2024] Open
Abstract
Cyanobacteria are important targets for biotechnological applications due to their ability to grow in a wide variety of environments, rapid growth rates, and tractable genetic systems. They and their bioproducts can be used as bioplastics, biofertilizers, and in carbon capture and produce important secondary metabolites that can be used as pharmaceuticals. However, the photosynthetic process in cyanobacteria can be limited by a wide variety of environmental factors such as light intensity and wavelength, exposure to UV light, nutrient limitation, temperature, and salinity. Carefully considering these limitations, modifying the environment, and/or selecting cyanobacterial species will allow cyanobacteria to be used in biotechnological applications.
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Affiliation(s)
- Christen L. Grettenberger
- Department of Earth and Planetary SciencesUniversity of California DavisDavisCaliforniaUSA
- Department of Environmental ToxicologyUniversity of California DavisDavisCaliforniaUSA
| | - Reda Abou‐Shanab
- Department of Plant and Microbial BiologyUniversity of MinnesotaSt. PaulMinnesotaUSA
| | - Trinity L. Hamilton
- Department of Plant and Microbial BiologyUniversity of MinnesotaSt. PaulMinnesotaUSA
- The Biotechnology Institute, University of MinnesotaSt. PaulMinnesotaUSA
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Fleischhacker-Daffert C, Zerobin A, Hummel F, Slaninova E, Kroupová Z, Obruca S, Mrazova K, Hrubanova K, Krzyzanek V, Nebesarova J, Ludwig K, Fritz I. A Comparison of the Effects of Continuous Illumination and Day/Night Regimes on PHB Accumulation in Synechocystis Cells. Life (Basel) 2024; 14:907. [PMID: 39063660 PMCID: PMC11278245 DOI: 10.3390/life14070907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2024] [Revised: 07/16/2024] [Accepted: 07/16/2024] [Indexed: 07/28/2024] Open
Abstract
Poly(3-hydroxybutyrate) (PHB) is a biobased and biodegradable polymer with properties comparable to polypropylene and therefore has the potential to replace conventional plastics. PHB is intracellularly accumulated by prokaryotic organisms. For the cells PHB functions manly as carbon and energy source, but all possible functions of PHB are still not known. Synechocystis (cyanobacteria) accumulates PHB using light as energy and CO2 as carbon source. The main trigger for PHB accumulation in cyanobacteria is nitrogen and phosphorous depletion with simultaneous surplus of carbon and energy. For the above reasons, obtaining knowledge about external factors influencing PHB accumulation is of highest interest. This study compares the effect of continuous light exposure and day/night (16/8 h) cycles on selected physiology parameters of three Synechocystis strains. We show that continuous illumination at moderate light intensities leads to an increased PHB accumulation in Synechocystis salina CCALA 192 (max. 14.2% CDW - cell dry weight) compared to day/night cycles (3.7% CDW). In addition to PHB content, glycogen and cell size increased, while cell density and cell viability decreased. The results offer new approaches for further studies to gain deeper insights into the role of PHB in cyanobacteria to obtain bioplastics in a more sustainable and environmentally friendly way.
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Affiliation(s)
- Christina Fleischhacker-Daffert
- Institute of Environmental Biotechnology, Department of Agrobiotechnology, IFA-Tulln, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz Straße 20, 3430 Tulln, Austria; (C.F.-D.); (F.H.); (I.F.)
| | - Antonia Zerobin
- Institute of Environmental Biotechnology, Department of Agrobiotechnology, IFA-Tulln, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz Straße 20, 3430 Tulln, Austria; (C.F.-D.); (F.H.); (I.F.)
| | - Ferdinand Hummel
- Institute of Environmental Biotechnology, Department of Agrobiotechnology, IFA-Tulln, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz Straße 20, 3430 Tulln, Austria; (C.F.-D.); (F.H.); (I.F.)
| | - Eva Slaninova
- Department of Food Chemistry and Biotechnology, Faculty of Chemistry, Brno University of Technology, Purkynova 118, 61200 Brno, Czech Republic; (E.S.); (Z.K.); (S.O.); (K.M.)
| | - Zuzana Kroupová
- Department of Food Chemistry and Biotechnology, Faculty of Chemistry, Brno University of Technology, Purkynova 118, 61200 Brno, Czech Republic; (E.S.); (Z.K.); (S.O.); (K.M.)
| | - Stanislav Obruca
- Department of Food Chemistry and Biotechnology, Faculty of Chemistry, Brno University of Technology, Purkynova 118, 61200 Brno, Czech Republic; (E.S.); (Z.K.); (S.O.); (K.M.)
| | - Katerina Mrazova
- Department of Food Chemistry and Biotechnology, Faculty of Chemistry, Brno University of Technology, Purkynova 118, 61200 Brno, Czech Republic; (E.S.); (Z.K.); (S.O.); (K.M.)
- Institute of Scientific Instruments, The Czech Academy of Sciences, Královopolská 147, 61264 Brno, Czech Republic; (K.H.); (V.K.)
| | - Kamila Hrubanova
- Institute of Scientific Instruments, The Czech Academy of Sciences, Královopolská 147, 61264 Brno, Czech Republic; (K.H.); (V.K.)
| | - Vladislav Krzyzanek
- Institute of Scientific Instruments, The Czech Academy of Sciences, Královopolská 147, 61264 Brno, Czech Republic; (K.H.); (V.K.)
| | - Jana Nebesarova
- Institute of Parasitology, Biology Centre, The Czech Academy of Sciences, Branisovska 31, 37005 Ceske Budejovice, Czech Republic;
- Faculty of Science, Charles University, Vinicna 7, 12844 Prague, Czech Republic
| | - Katharina Ludwig
- BEST—Bioenergy and Sustainable Technologies GmbH, Inffeldgasse 21b, 8010 Graz, Austria
| | - Ines Fritz
- Institute of Environmental Biotechnology, Department of Agrobiotechnology, IFA-Tulln, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz Straße 20, 3430 Tulln, Austria; (C.F.-D.); (F.H.); (I.F.)
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Ran Z, Du Z, Miao G, Zheng M, Luo L, Pang X, Wei L, Li D, Ma W. Identification of a c-type heme oxygenase and its function during acclimation of cyanobacteria to nitrogen fluctuations. Commun Biol 2023; 6:944. [PMID: 37714932 PMCID: PMC10504260 DOI: 10.1038/s42003-023-05315-x] [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: 10/19/2022] [Accepted: 09/01/2023] [Indexed: 09/17/2023] Open
Abstract
The mechanisms of acclimating to a nitrogen-fluctuating environment are necessary for the survival of aquatic cyanobacteria in their natural habitats, but our understanding is still far from complete. Here, the synthesis of phycobiliprotein is confirmed to be much earlier than that of photosystem components during recovery from nitrogen chlorosis and an unknown protein Ssr1698 is discovered to be involved in this synthetic process. The unknown protein is further identified as a c-type heme oxygenase (cHO) in tetrapyrrole biosynthetic pathway and catalyzes the opening of heme ring to form biliverdin IXα, which is required for phycobilin production and ensuing phycobiliprotein synthesis. In addition, the cHO-dependent phycobiliprotein is found to be vital for the growth of cyanobacterial cells during chlorosis and regreening through its nitrogen-storage and light-harvesting functions, respectively. Collectively, the cHO expressed preferentially during recovery from nitrogen chlorosis is identified in photosynthetic organisms and the dual function of this enzyme-dependent phycobiliprotein is proposed to be an important mechanism for acclimation of aquatic cyanobacteria to a nitrogen-fluctuating environment.
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Affiliation(s)
- Zhaoxing Ran
- School of Ecological and Environmental Sciences, East China Normal University, 200241, Shanghai, China
- College of Life Sciences, Shanghai Normal University, 200234, Shanghai, China
| | - Zhenyu Du
- College of Life Sciences, Shanghai Normal University, 200234, Shanghai, China
| | - Gengkai Miao
- College of Life Sciences, Shanghai Normal University, 200234, Shanghai, China
| | - Mei Zheng
- College of Life Sciences, Shanghai Normal University, 200234, Shanghai, China
| | - Ligang Luo
- College of Life Sciences, Shanghai Normal University, 200234, Shanghai, China
| | - Xiaoqin Pang
- College of Life Sciences, Shanghai Normal University, 200234, Shanghai, China
| | - Lanzhen Wei
- College of Life Sciences, Shanghai Normal University, 200234, Shanghai, China.
| | - Dezhi Li
- School of Ecological and Environmental Sciences, East China Normal University, 200241, Shanghai, China.
- Key Laboratory of Urbanization and Ecological Restoration of Shanghai, 200241, Shanghai, China.
- Institute of Eco-Chongming (IEC), 20 Cuiniao Rd, Chenjia Zhen, Chongming, 202162, Shanghai, China.
- Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, 3663 N. Zhongshan Road, 200062, Shanghai, China.
| | - Weimin Ma
- College of Life Sciences, Shanghai Normal University, 200234, Shanghai, China.
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Glucosidase Inhibitors Screening in Microalgae and Cyanobacteria Isolated from the Amazon and Proteomic Analysis of Inhibitor Producing Synechococcus sp. GFB01. Microorganisms 2021; 9:microorganisms9081593. [PMID: 34442672 PMCID: PMC8402191 DOI: 10.3390/microorganisms9081593] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 07/01/2021] [Accepted: 07/02/2021] [Indexed: 11/17/2022] Open
Abstract
Microalgae and cyanobacteria are good sources for prospecting metabolites of biotechnological interest, including glucosidase inhibitors. These inhibitors act on enzymes related to various biochemical processes; they are involved in metabolic diseases, such as diabetes and Gaucher disease, tumors and viral infections, thus, they are interesting hubs for the development of new drugs and therapies. In this work, the screening of 63 environmental samples collected in the Brazilian Amazon found activity against β-glucosidase, of at least 60 min, in 13.85% of the tested extracts, with Synechococcus sp. GFB01 showing inhibitory activity of 90.2% for α-glucosidase and 96.9% against β-glucosidase. It was found that the nutritional limitation due to a reduction in the concentration of sodium nitrate, despite not being sufficient to cause changes in cell growth and photosynthetic apparatus, resulted in reduced production of α and β-glucosidase inhibitors and differential protein expression. The proteomic analysis of cyanobacteria isolated from the Amazon is unprecedented, with this being the first work to evaluate the protein expression of Synechococcus sp. GFB01 subjected to nutritional stress. This evaluation helps to better understand the metabolic responses of this organism, especially related to the production of inhibitors, adding knowledge to the industrial potential of these cyanobacterial compounds.
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Zavřel T, Schoffman H, Lukeš M, Fedorko J, Keren N, Červený J. Monitoring fitness and productivity in cyanobacteria batch cultures. ALGAL RES 2021. [DOI: 10.1016/j.algal.2021.102328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Photosynthetic monitoring techniques indicate maximum glycogen accumulation in nitrogen-limited Synechocystis sp. PCC 6803 culture. ALGAL RES 2021. [DOI: 10.1016/j.algal.2021.102271] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Fuente D, Lazar D, Oliver-Villanueva JV, Urchueguía JF. Reconstruction of the absorption spectrum of Synechocystis sp. PCC 6803 optical mutants from the in vivo signature of individual pigments. PHOTOSYNTHESIS RESEARCH 2021; 147:75-90. [PMID: 33245462 DOI: 10.1007/s11120-020-00799-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 11/13/2020] [Indexed: 06/11/2023]
Abstract
In this work, we reconstructed the absorption spectrum of different Synechocystis sp. PCC 6803 optical strains by summing the computed signature of all pigments present in this organism. To do so, modifications to in vitro pigment spectra were first required: namely wavelength shift, curve smoothing, and the package effect calculation derived from high pigment densities were applied. As a result, we outlined a plausible shape for the in vivo absorption spectrum of each chromophore. These are flatter and slightly broader in physiological conditions yet the mean weight-specific absorption coefficient remains identical to the in vitro conditions. Moreover, we give an estimate of all pigment concentrations without applying spectrophotometric correlations, which are often prone to error. The computed cell spectrum reproduces in an accurate manner the experimental spectrum for all the studied wavelengths in the wild-type, Olive, and PAL strain. The gathered pigment concentrations are in agreement with reported values in literature. Moreover, different illumination set-ups were evaluated to calculate the mean absorption cross-section of each chromophore. Finally, a qualitative estimate of light-limited cellular growth at each wavelength is given. This investigation describes a novel way to approach the cell absorption spectrum and shows all its inherent potential for photosynthesis research.
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Affiliation(s)
- David Fuente
- Instituto de Aplicaciones de las Tecnologías de la Información y de las Comunicaciones Avanzadas, Universitat Politècnica de València, Valencia, Spain.
- Department of Biophysics, Faculty of Science, Palacký University, Olomouc, Czech Republic.
- Department of Adaptation Biotechnologies, Global Change Research Centre, Academy of Science of the Czech Republic, Drásov, Czech Republic.
| | - Dusan Lazar
- Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - Jose Vicente Oliver-Villanueva
- Instituto de Aplicaciones de las Tecnologías de la Información y de las Comunicaciones Avanzadas, Universitat Politècnica de València, Valencia, Spain
| | - Javier F Urchueguía
- Instituto de Aplicaciones de las Tecnologías de la Información y de las Comunicaciones Avanzadas, Universitat Politècnica de València, Valencia, Spain
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Luimstra VM, Schuurmans JM, Hellingwerf KJ, Matthijs HCP, Huisman J. Blue light induces major changes in the gene expression profile of the cyanobacterium Synechocystis sp. PCC 6803. PHYSIOLOGIA PLANTARUM 2020; 170:10-26. [PMID: 32141606 PMCID: PMC7496141 DOI: 10.1111/ppl.13086] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 02/28/2020] [Accepted: 03/04/2020] [Indexed: 05/18/2023]
Abstract
Although cyanobacteria absorb blue light, they use it less efficiently for photosynthesis than other colors absorbed by their photosynthetic pigments. A plausible explanation for this enigmatic phenomenon is that blue light is not absorbed by phycobilisomes and, hence, causes an excitation shortage at photosystem II (PSII). This hypothesis is supported by recent physiological studies, but a comprehensive understanding of the underlying changes in gene expression is still lacking. In this study, we investigate how a switch from artificial white light to blue, orange or red light affects the transcriptome of the cyanobacterium Synechocystis sp. PCC 6803. In total, 145 genes were significantly regulated in response to blue light, whereas only a few genes responded to orange and red light. In particular, genes encoding the D1 and D2 proteins of PSII, the PSII chlorophyll-binding protein CP47 and genes involved in PSII repair were upregulated in blue light, whereas none of the photosystem I (PSI) genes responded to blue light. These changes were accompanied by a decreasing PSI:PSII ratio. Furthermore, many genes involved in gene transcription and translation and several ATP synthase genes were transiently downregulated, concurrent with a temporarily decreased growth rate in blue light. After 6-7 days, when cell densities had strongly declined, the growth rate recovered and the expression of these growth-related genes returned to initial levels. Hence, blue light induces major changes in the transcriptome of cyanobacteria, in an attempt to increase the photosynthetic activity of PSII and cope with the adverse growth conditions imposed by blue light.
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Affiliation(s)
- Veerle M. Luimstra
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem DynamicsUniversity of AmsterdamAmsterdamThe Netherlands
- Wetsus – Center of Excellence for Sustainable Water TechnologyLeeuwardenThe Netherlands
| | - J. Merijn Schuurmans
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem DynamicsUniversity of AmsterdamAmsterdamThe Netherlands
| | - Klaas J. Hellingwerf
- Swammerdam Institute for Life SciencesUniversity of AmsterdamAmsterdamThe Netherlands
| | - Hans C. P. Matthijs
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem DynamicsUniversity of AmsterdamAmsterdamThe Netherlands
| | - Jef Huisman
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem DynamicsUniversity of AmsterdamAmsterdamThe Netherlands
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Zhou Y, Li X, Xia Q, Dai R. Transcriptomic survey on the microcystins production and growth of Microcystis aeruginosa under nitrogen starvation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 700:134501. [PMID: 31689655 DOI: 10.1016/j.scitotenv.2019.134501] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/15/2019] [Accepted: 09/15/2019] [Indexed: 06/10/2023]
Abstract
Cyanobacteria are a vital component of freshwater phytoplankton, and many species are recognized for their ability to produce toxins and harmful algal blooms (HABs). Nitrogen is an essential element of all the complex macromolecules in algal cells. However, the underlying molecular mechanism of the changes in transcriptomic patterns and physiological responses in response to N starvation is poorly understood. The transcriptomes were generated via RNA-sequencing (RNA-Seq) technology to study the major metabolic pathway under N starvation. The results shed light on the mechanism of toxin production and physiological adaptations in Microcystis aeruginosa (M. aeruginosa). The cell density gradually increased during the first two days then declined over time and was finally stable at (15.50 ± 0.5) × 105 cell mL-1 after 6 days. The chlorophyll-a content and phycocyanin content of M. aeruginosa increased during the first two days and subsequently decreased markedly over time under N starvation. The variable to maximum chlorophyll fluorescence ratio (Fv/Fm ratio) decreased with time under N starvation. Most photosynthesis genes have similarity decreasing trends with growth physiological changes. The microcystins (MCs) levels generally increased first, reaching a peak value with 1.35 pg cell-1 on the fifth day, and then remained roughly constant. The genes involved in N metabolism-related gene expression were upregulated to maintain normal biological activity, while the genes involved in photosynthesis-related gene expression were downregulated to save energy. All genes encoding algae toxin synthesis were upregulated under N starvation. The observed expression patterns demonstrate that all MCs genes respond similarly to MCs production within the cell. Our results indicate the response mechanism of M. aeruginosa under N starvation and provide a comprehensive understanding of N-controlling cyanobacteria and MCs synthesis.
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Affiliation(s)
- Yanping Zhou
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Xuan Li
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Qiongqiong Xia
- North China Municipal Engineering Design & Research Institute Co. Ltd., Tianjin 300074, China
| | - Ruihua Dai
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
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Zhou Y, Zhang X, Li X, Jia P, Dai R. Evaluation of changes in Microcystis aeruginosa growth and microcystin production by urea via transcriptomic surveys. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 655:181-187. [PMID: 30469064 DOI: 10.1016/j.scitotenv.2018.11.100] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 11/02/2018] [Accepted: 11/07/2018] [Indexed: 06/09/2023]
Abstract
The freshwater cyanobacteria, Microcystis aeruginosa (M. aeruginosa), is well known to produce microcystins (MCs) and induce the formation of harmful algal blooms (HABs) in aquatic environments, but the effects that urea fertilizer has on cyanobacterial growth and toxin production from a molecular biology perspective remain poorly understood. We evaluated changes in the growth and toxicity of M. aeruginosa cultured under different conditions of nitrogen (N) starvation (NN), low nitrogen (LN), and high nitrogen (HN). Cell density and chlorophyll-a concentrations decreased in cyanobacteria exposed to N starvation and increased following the addition of urea, whereas MCs content increased to a peak and then decreased after urea addition. Transcriptomic analysis confirmed that most genes encoding MCs and genes involved in N metabolic pathways were upregulated under N starvation and LN conditions, whereas these genes were downregulated under HN conditions. Our results offer important insights into the exploring N in controlling the formation of HABs and toxin production based on both physiological and molecular response.
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Affiliation(s)
- Yanping Zhou
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Xufeng Zhang
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Xuan Li
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Peili Jia
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Ruihua Dai
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China.
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Comparative Targeted Proteomics of the Central Metabolism and Photosystems in SigE Mutant Strains of Synechocystis sp. PCC 6803. Molecules 2018; 23:molecules23051051. [PMID: 29723969 PMCID: PMC6102573 DOI: 10.3390/molecules23051051] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 04/27/2018] [Accepted: 04/27/2018] [Indexed: 12/17/2022] Open
Abstract
A targeted proteome analysis was conducted to investigate the SigE dependent-regulation of central metabolism in Synechocystis sp. PCC 6803 by directly comparing the protein abundance profiles among the wild type, a sigE deletion mutant (ΔsigE), and a sigE over-expression (sigEox) strains. Expression levels of 112 target proteins, including the central metabolism related-enzymes and the subunits of the photosystems, were determined by quantifying the tryptic peptides in the multiple reaction monitoring (MRM) mode of liquid-chromatography–triple quadrupole mass spectrometry (LC–MS/MS). Comparison with gene-expression data showed that although the abundance of Gnd protein was closely correlated with that of gnd mRNA, there were poor correlations for GdhA/gdhA and glycogen degradation-related genes such as GlgX/glgX and GlgP/glgP pairs. These results suggested that the regulation of protein translation and degradation played a role in regulating protein abundance. The protein abundance profile suggested that SigE overexpression reduced the proteins involved in photosynthesis and increased GdhA abundance, which is involved in the nitrogen assimilation pathway using NADPH. The results obtained in this study successfully demonstrated that targeted proteome analysis enables direct comparison of the abundance of central metabolism- and photosystem-related proteins.
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6S RNA plays a role in recovery from nitrogen depletion in Synechocystis sp. PCC 6803. BMC Microbiol 2017; 17:229. [PMID: 29216826 PMCID: PMC5721685 DOI: 10.1186/s12866-017-1137-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 11/27/2017] [Indexed: 12/30/2022] Open
Abstract
Background The 6S RNA is a global transcriptional riboregulator, which is exceptionally widespread among most bacterial phyla. While its role is well-characterized in some heterotrophic bacteria, we subjected a cyanobacterial homolog to functional analysis, thereby extending the scope of 6S RNA action to the special challenges of photoautotrophic lifestyles. Results Physiological characterization of a 6S RNA deletion strain (ΔssaA) demonstrates a delay in the recovery from nitrogen starvation. Significantly decelerated phycobilisome reassembly and glycogen degradation are accompanied with reduced photosynthetic activity compared to the wild type. Transcriptome profiling further revealed that predominantly genes encoding photosystem components, ATP synthase, phycobilisomes and ribosomal proteins were negatively affected in ΔssaA. In vivo pull-down studies of the RNA polymerase complex indicated that the presence of 6S RNA promotes the recruitment of the cyanobacterial housekeeping σ factor SigA, concurrently supporting dissociation of group 2 σ factors during recovery from nitrogen starvation. Conclusions The combination of genetic, physiological and biochemical studies reveals the homologue of 6S RNA as an integral part of the cellular response of Synechocystis sp. PCC 6803 to changing nitrogen availability. According to these results, 6S RNA supports a rapid acclimation to changing nitrogen supply by accelerating the switch from group 2 σ factors SigB, SigC and SigE to SigA-dependent transcription. We therefore introduce the cyanobacterial 6S RNA as a novel candidate regulator of RNA polymerase sigma factor recruitment in Synechocystis sp. PCC 6803. Further studies on mechanistic features of the postulated interaction should shed additional light on the complexity of transcriptional regulation in cyanobacteria. Electronic supplementary material The online version of this article (10.1186/s12866-017-1137-9) contains supplementary material, which is available to authorized users.
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de Porcellinis AJ, Klähn S, Rosgaard L, Kirsch R, Gutekunst K, Georg J, Hess WR, Sakuragi Y. The Non-Coding RNA Ncr0700/PmgR1 is Required for Photomixotrophic Growth and the Regulation of Glycogen Accumulation in the Cyanobacterium Synechocystis sp. PCC 6803. PLANT & CELL PHYSIOLOGY 2016; 57:2091-2103. [PMID: 27440548 DOI: 10.1093/pcp/pcw128] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 07/12/2016] [Indexed: 06/06/2023]
Abstract
Carbohydrate metabolism is a tightly regulated process in photosynthetic organisms. In the cyanobacterium Synechocystis sp. PCC 6803, the photomixotrophic growth protein A (PmgA) is involved in the regulation of glucose and storage carbohydrate (i.e. glycogen) metabolism, while its biochemical activity and possible factors acting downstream of PmgA are unknown. Here, a genome-wide microarray analysis of a ΔpmgA strain identified the expression of 36 protein-coding genes and 42 non-coding transcripts as significantly altered. From these, the non-coding RNA Ncr0700 was identified as the transcript most strongly reduced in abundance. Ncr0700 is widely conserved among cyanobacteria. In Synechocystis its expression is inversely correlated with light intensity. Similarly to a ΔpmgA mutant, a Δncr0700 deletion strain showed an approximately 2-fold increase in glycogen content under photoautotrophic conditions and wild-type-like growth. Moreover, its growth was arrested by 38 h after a shift to photomixotrophic conditions. Ectopic expression of Ncr0700 in Δncr0700 and ΔpmgA restored the glycogen content and photomixotrophic growth to wild-type levels. These results indicate that Ncr0700 is required for photomixotrophic growth and the regulation of glycogen accumulation, and acts downstream of PmgA. Hence Ncr0700 is renamed here as PmgR1 for photomixotrophic growth RNA 1.
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Affiliation(s)
- Alice J de Porcellinis
- Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, DK-1871, Denmark
- These authors contributed equally to this work
| | - Stephan Klähn
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Schänzlestr. 1, Freiburg, D-79104, Germany
- These authors contributed equally to this work
| | - Lisa Rosgaard
- Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, DK-1871, Denmark
- Present address: R&D Renescience Thermal Power, DONG Energy, Skærbæk-7000 Fredericia, Denmark
| | - Rebekka Kirsch
- Botanical Institute, Christian-Albrechts-University, Am Botanischen Garten 5, Kiel, D-24118, Germany
| | - Kirstin Gutekunst
- Botanical Institute, Christian-Albrechts-University, Am Botanischen Garten 5, Kiel, D-24118, Germany
| | - Jens Georg
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Schänzlestr. 1, Freiburg, D-79104, Germany
| | - Wolfgang R Hess
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Schänzlestr. 1, Freiburg, D-79104, Germany
| | - Yumiko Sakuragi
- Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, DK-1871, Denmark
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Benson PJ, Purcell-Meyerink D, Hocart CH, Truong TT, James GO, Rourke L, Djordjevic MA, Blackburn SI, Price GD. Factors Altering Pyruvate Excretion in a Glycogen Storage Mutant of the Cyanobacterium, Synechococcus PCC7942. Front Microbiol 2016; 7:475. [PMID: 27092129 PMCID: PMC4820439 DOI: 10.3389/fmicb.2016.00475] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 03/22/2016] [Indexed: 12/20/2022] Open
Abstract
Interest in the production of carbon commodities from photosynthetically fixed CO2 has focused attention on cyanobacteria as a target for metabolic engineering and pathway investigation. We investigated the redirection of carbon flux in the model cyanobacterial species, Synechococcus elongatus PCC 7942, under nitrogen deprivation, for optimized production of the industrially desirable compound, pyruvate. Under nitrogen limited conditions, excess carbon is naturally stored as the multi-branched polysaccharide, glycogen, but a block in glycogen synthesis, via knockout mutation in the gene encoding ADP-glucose pyrophosphorylase (glgC), results in the accumulation of the organic acids, pyruvate and 2-oxoglutarate, as overflow excretions into the extracellular media. The ΔglgC strain, under 48 h of N-deprivation was shown to excrete pyruvate for the first time in this strain. Additionally, by increasing culture pH, to pH 10, it was possible to substantially elevate excretion of pyruvate, suggesting the involvement of an unknown substrate/proton symporter for export. The ΔglgC mutant was also engineered to express foreign transporters for glucose and sucrose, and then grown photomixotrophically with exogenous organic carbon supply, as added 5 mM glucose or sucrose during N- deprivation. Under these conditions we observed a fourfold increase in extracellular pyruvate excretion when glucose was added, and a smaller increase with added sucrose. Although the magnitude of pyruvate excretion did not correlate with the capacity of the ΔglgC strain for bicarbonate-dependent photosynthetic O2 evolution, or with light intensity, there was, however, a positive correlation observed between the density of the starter culture prior to N-deprivation and the final extracellular pyruvate concentration. The factors that contribute to enhancement of pyruvate excretion are discussed, as well as consideration of whether the source of carbon for pyruvate excretion might be derived from photosynthetic CO2 fixation or from remobilisation of existing carbon stores.
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Affiliation(s)
- Phoebe J Benson
- Research School of Biology, Plant Sciences, Australian National University, Canberra ACT, Australia
| | - Diane Purcell-Meyerink
- Research School of Biology, Plant Sciences, Australian National University, CanberraACT, Australia; North Australia Marine Research Alliance, Arafura Timor Research Facility, DarwinNT, Australia
| | - Charles H Hocart
- Research School of Biology, Plant Sciences, Australian National University, Canberra ACT, Australia
| | - Thy T Truong
- Research School of Biology, Plant Sciences, Australian National University, Canberra ACT, Australia
| | - Gabriel O James
- Research School of Biology, Plant Sciences, Australian National University, CanberraACT, Australia; Heliase Genomics, University of AucklandAuckland, New Zealand
| | - Loraine Rourke
- Research School of Biology, Plant Sciences, Australian National University, Canberra ACT, Australia
| | - Michael A Djordjevic
- Research School of Biology, Plant Sciences, Australian National University, Canberra ACT, Australia
| | - Susan I Blackburn
- CSIRO National Research Collections Australia, Hobart TAS, Australia
| | - G D Price
- Research School of Biology, Plant Sciences, Australian National University, Canberra ACT, Australia
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Deletion of the gene family of small chlorophyll-binding proteins (ScpABCDE) offsets C/N homeostasis in Synechocystis PCC 6803. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:396-407. [DOI: 10.1016/j.bbabio.2015.11.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 11/20/2015] [Accepted: 11/27/2015] [Indexed: 02/03/2023]
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Osanai T, Iijima H, Hirai MY. Understanding Sugar Catabolism in Unicellular Cyanobacteria Toward the Application in Biofuel and Biomaterial Production. Subcell Biochem 2016; 86:511-523. [PMID: 27023248 DOI: 10.1007/978-3-319-25979-6_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Synechocystis sp. PCC 6803 is a model species of the cyanobacteria that undergo oxygenic photosynthesis, and has garnered much attention for its potential biotechnological applications. The regulatory mechanism of sugar metabolism in this cyanobacterium has been intensively studied and recent omics approaches have revealed the changes in transcripts, proteins, and metabolites of sugar catabolism under different light and nutrient conditions. Several transcriptional regulators that control the gene expression of enzymes related to sugar catabolism have been identified in the past 10 years, including a sigma factor, transcription factors, and histidine kinases. The modification of these genes can lead to alterations in the primary metabolism as well as the levels of high-value products such as bioplastics and hydrogen. This review summarizes recent studies on sugar catabolism in Synechocystis sp. PCC 6803, emphasizing the importance of elucidating the molecular mechanisms of cyanobacterial metabolism for biotechnological applications.
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Affiliation(s)
- Takashi Osanai
- School of Agriculture, Meiji University, 1-1-1, Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan.
| | - Hiroko Iijima
- School of Agriculture, Meiji University, 1-1-1, Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan
| | - Masami Yokota Hirai
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
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Harke MJ, Gobler CJ. Daily transcriptome changes reveal the role of nitrogen in controlling microcystin synthesis and nutrient transport in the toxic cyanobacterium, Microcystis aeruginosa. BMC Genomics 2015; 16:1068. [PMID: 26673568 PMCID: PMC4681089 DOI: 10.1186/s12864-015-2275-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 12/03/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND While transcriptomics have become a valuable tool for linking physiology and ecology in aquatic microbes, the temporal dynamics of global transcriptomic patterns in Microcystis have rarely been assessed. Furthermore, while many microbial studies have explored expression of nutrient transporter genes, few studies have concurrently measured nutrient assimilation rates. Here, we considered how the global transcriptomic patterns and physiology of the cyanobacterium, Microcystis aeruginosa, changed daily as cells were grown from replete to deficient nitrogen (N) conditions and then back to replete conditions. RESULTS During N deprivation, Microcystis downregulated genes involved in photosynthesis and respiration, carbon acquisition, lipid metabolism, and amino acid biosynthesis while upregulating genes involved in N acquisition and transport. With increasing N stress, both the strength of expression and number of genes being differentially expressed increased, until N was restored at which point these patterns reversed. Uptake of (15)N-labeled nitrate, ammonium and urea reflected differential expression of genes encoding transporters for these nutrients, with Microcystis appearing to preferentially increase transcription of ammonium and urea transporters and uptake of these compounds during N deprivation. Nitrate uptake and nitrate transporter expression were correlated for one set of transporters but not another, indicating these were high and low affinity nitrate transporters, respectively. Concentrations of microcystin per cell decreased during N deprivation and increased upon N restoration. However, the transcript abundance of genes involved in the synthesis of this compound was complex, as microcystin synthetase genes involved in peptide synthesis were downregulated under N deprivation while genes involved in tailoring and transport were upregulated, suggesting modification of the microcystin molecule under N stress as well as potential alternative functions for these genes and/or this toxin. CONCLUSIONS Collectively, this study highlights the complex choreography of gene expression, cell physiology, and toxin synthesis that dynamic N levels can elicit in this ecologically important cyanobacterium. Differing expression patterns of genes within the microcystin synthetase operon in response to changing N levels revealed the potential limitations drawing conclusions based on only one gene in this operon.
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Affiliation(s)
- Matthew J Harke
- School of Marine and Atmospheric Sciences, Stony Brook University, 239 Montauk Hwy, Southampton, NY, 11968, USA.
| | - Christopher J Gobler
- School of Marine and Atmospheric Sciences, Stony Brook University, 239 Montauk Hwy, Southampton, NY, 11968, USA.
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Regulation of the scp Genes in the Cyanobacterium Synechocystis sp. PCC 6803--What is New? Molecules 2015; 20:14621-37. [PMID: 26274949 PMCID: PMC6331805 DOI: 10.3390/molecules200814621] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 08/05/2015] [Accepted: 08/07/2015] [Indexed: 11/18/2022] Open
Abstract
In the cyanobacterium Synechocystis sp. PCC 6803 there are five genes encoding small CAB-like (SCP) proteins, which have been shown to be up-regulated under stress. Analyses of the promoter sequences of the scp genes revealed the existence of an NtcA binding motif in two scp genes, scpB and scpE. Binding of NtcA, the key transcriptional regulator during nitrogen stress, to the promoter regions was shown by electrophoretic mobility shift assay. The metabolite 2-oxoglutarate did not increase the affinity of NtcA for binding to the promoters of scpB and scpE. A second motif, the HIP1 palindrome 5ʹ GGCGATCGCC 3ʹ, was detected in the upstream regions of scpB and scpC. The transcription factor encoded by sll1130 has been suggested to recognize this motif to regulate heat-responsive genes. Our data suggest that HIP1 is not a regulatory element within the scp genes. Further, the presence of the high light regulatory (HLR1) motif was confirmed in scpB-E, in accordance to their induced transcriptions in cells exposed to high light. The HLR1 motif was newly discovered in eight additional genes.
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Depraetere O, Deschoenmaeker F, Badri H, Monsieurs P, Foubert I, Leys N, Wattiez R, Muylaert K. Trade-Off between Growth and Carbohydrate Accumulation in Nutrient-Limited Arthrospira sp. PCC 8005 Studied by Integrating Transcriptomic and Proteomic Approaches. PLoS One 2015. [PMID: 26196510 PMCID: PMC4509649 DOI: 10.1371/journal.pone.0132461] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Cyanobacteria have a strong potential for biofuel production due to their ability to accumulate large amounts of carbohydrates. Nitrogen (N) stress can be used to increase the content of carbohydrates in the biomass, but it is expected to reduce biomass productivity. To study this trade-off between carbohydrate accumulation and biomass productivity, we characterized the biomass productivity, biomass composition as well as the transcriptome and proteome of the cyanobacterium Arthrospira sp. PCC 8005 cultured under N-limiting and N-replete conditions. N limitation resulted in a large increase in the carbohydrate content of the biomass (from 14 to 74%) and a decrease in the protein content (from 37 to 10%). Analyses of fatty acids indicated that no lipids were accumulated under N-limited conditions. Nevertheless, it did not affect the biomass productivity of the culture up to five days after N was depleted from the culture medium. Transcriptomic and proteomic analysis indicated that de novo protein synthesis was down-regulated in the N-limited culture. Proteins were degraded and partly converted into carbohydrates through gluconeogenesis. Cellular N derived from protein degradation was recycled through the TCA and GS-GOGAT cycles. In addition, photosynthetic energy production and carbon fixation were both down-regulated, while glycogen synthesis was up-regulated. Our results suggested that N limitation resulted in a redirection of photosynthetic energy from protein synthesis to glycogen synthesis. The fact that glycogen synthesis has a lower energy demand than protein synthesis might explain why Arthrospira is able to achieve a similar biomass productivity under N-limited as under N-replete conditions despite the fact that photosynthetic energy production was impaired by N limitation.
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Affiliation(s)
- Orily Depraetere
- KU Leuven campus Kortrijk, Laboratory Aquatic Biology, E. Sabbelaan 53, 8500, Kortrijk, Belgium
- * E-mail:
| | - Frédéric Deschoenmaeker
- Department of Proteomic and Microbiology, Research Institute for Biosciences, University of Mons, Place du Parc 20, 7000, Mons, Belgium
| | - Hanène Badri
- Expert Group for Molecular and Cellular Biology MCB, Belgian Nuclear Research Center SCK.CEN, 2400, Mol, Belgium
| | - Pieter Monsieurs
- Expert Group for Molecular and Cellular Biology MCB, Belgian Nuclear Research Center SCK.CEN, 2400, Mol, Belgium
| | - Imogen Foubert
- KU Leuven campus Kortrijk, Research Unit Food & Lipids, Department of Molecular and Microbial Systems Kulak, Etienne Sabbelaan 53, 8500, Kortrijk, Belgium
| | - Natalie Leys
- Expert Group for Molecular and Cellular Biology MCB, Belgian Nuclear Research Center SCK.CEN, 2400, Mol, Belgium
| | - Ruddy Wattiez
- Department of Proteomic and Microbiology, Research Institute for Biosciences, University of Mons, Place du Parc 20, 7000, Mons, Belgium
| | - Koenraad Muylaert
- KU Leuven campus Kortrijk, Laboratory Aquatic Biology, E. Sabbelaan 53, 8500, Kortrijk, Belgium
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20
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Aguirre-von-Wobeser E, Eguiarte LE, Souza V, Soberón-Chávez G. Theoretical analysis of the cost of antagonistic activity for aquatic bacteria in oligotrophic environments. Front Microbiol 2015; 6:490. [PMID: 26074891 PMCID: PMC4444843 DOI: 10.3389/fmicb.2015.00490] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 05/04/2015] [Indexed: 01/11/2023] Open
Abstract
Many strains of bacteria produce antagonistic substances that restrain the growth of others, and potentially give them a competitive advantage. These substances are commonly released to the surrounding environment, involving metabolic costs in terms of energy and nutrients. The rate at which these molecules need to be produced to maintain a certain amount of them close to the producing cell before they are diluted into the environment has not been explored so far. To understand the potential cost of production of antagonistic substances in water environments, we used two different theoretical approaches. Using a probabilistic model, we determined the rate at which a cell needs to produce individual molecules in order to keep on average a single molecule in its vicinity at all times. For this minimum protection, a cell would need to invest 3.92 × 10(-22) kg s(-1) of organic matter, which is 9 orders of magnitude lower than the estimated expense for growth. Next, we used a continuous model, based on Fick's laws, to explore the production rate needed to sustain minimum inhibitory concentrations around a cell, which would provide much more protection from competitors. In this scenario, cells would need to invest 1.20 × 10(-11) kg s(-1), which is 2 orders of magnitude higher than the estimated expense for growth, and thus not sustainable. We hypothesize that the production of antimicrobial compounds by bacteria in aquatic environments lies between these two extremes.
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Affiliation(s)
| | - Luis E Eguiarte
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México Mexico City, Mexico
| | - Valeria Souza
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México Mexico City, Mexico
| | - Gloria Soberón-Chávez
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México Mexico City, Mexico
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21
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Spät P, Maček B, Forchhammer K. Phosphoproteome of the cyanobacterium Synechocystis sp. PCC 6803 and its dynamics during nitrogen starvation. Front Microbiol 2015; 6:248. [PMID: 25873915 PMCID: PMC4379935 DOI: 10.3389/fmicb.2015.00248] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 03/13/2015] [Indexed: 12/02/2022] Open
Abstract
Cyanobacteria have shaped the earth's biosphere as the first oxygenic photoautotrophs and still play an important role in many ecosystems. The ability to adapt to changing environmental conditions is an essential characteristic in order to ensure survival. To this end, numerous studies have shown that bacteria use protein post-translational modifications such as Ser/Thr/Tyr phosphorylation in cell signaling, adaptation, and regulation. Nevertheless, our knowledge of cyanobacterial phosphoproteomes and their dynamic response to environmental stimuli is relatively limited. In this study, we applied gel-free methods and high accuracy mass spectrometry toward the detection of Ser/Thr/Tyr phosphorylation events in the model cyanobacterium Synechocystis sp. PCC 6803. We could identify over 300 phosphorylation events in cultures grown on nitrate as exclusive nitrogen source. Chemical dimethylation labeling was applied to investigate proteome and phosphoproteome dynamics during nitrogen starvation. Our dataset describes the most comprehensive (phospho)proteome of Synechocystis to date, identifying 2382 proteins and 183 phosphorylation events and quantifying 2111 proteins and 148 phosphorylation events during nitrogen starvation. Global protein phosphorylation levels were increased in response to nitrogen depletion after 24 h. Among the proteins with increased phosphorylation, the PII signaling protein showed the highest fold-change, serving as positive control. Other proteins with increased phosphorylation levels comprised functions in photosynthesis and in carbon and nitrogen metabolism. This study reveals dynamics of Synechocystis phosphoproteome in response to environmental stimuli and suggests an important role of protein Ser/Thr/Tyr phosphorylation in fundamental mechanisms of homeostatic control in cyanobacteria.
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Affiliation(s)
- Philipp Spät
- Department of Organismic Interactions, Interfaculty Institute for Microbiology and Infection Medicine, Eberhard-Karls-University Tübingen Tübingen, Germany
| | - Boris Maček
- Interfaculty Institute for Cell Biology, Proteome Center Tuebingen, Eberhard-Karls-University Tübingen Tübingen, Germany
| | - Karl Forchhammer
- Department of Organismic Interactions, Interfaculty Institute for Microbiology and Infection Medicine, Eberhard-Karls-University Tübingen Tübingen, Germany
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22
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Badri H, Monsieurs P, Coninx I, Wattiez R, Leys N. Molecular investigation of the radiation resistance of edible cyanobacterium Arthrospira sp. PCC 8005. Microbiologyopen 2015; 4:187-207. [PMID: 25678338 PMCID: PMC4398503 DOI: 10.1002/mbo3.229] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 10/28/2014] [Accepted: 11/10/2014] [Indexed: 01/28/2023] Open
Abstract
The aim of this work was to characterize in detail the response of Arthrospira to ionizing radiation, to better understand its radiation resistance capacity. Live cells of Arthrospira sp. PCC 8005 were irradiated with 60Co gamma rays. This study is the first, showing that Arthrospira is highly tolerant to gamma rays, and can survive at least 6400 Gy (dose rate of 527 Gy h−1), which identified Arthrospira sp. PCC 8005 as a radiation resistant bacterium. Biochemical, including proteomic and transcriptomic, analysis after irradiation with 3200 or 5000 Gy showed a decline in photosystem II quantum yield, reduced carbon fixation, and reduced pigment, lipid, and secondary metabolite synthesis. Transcription of photo-sensing and signaling pathways, and thiol-based antioxidant systems was induced. Transcriptomics did show significant activation of ssDNA repair systems and mobile genetic elements (MGEs) at the RNA level. Surprisingly, the cells did not induce the classical antioxidant or DNA repair systems, such superoxide dismutase (SOD) enzyme and the RecA protein. Arthrospira cells lack the catalase gene and the LexA repressor. Irradiated Arthrospira cells did induce strongly a group of conserved proteins, of which the function in radiation resistance remains to be elucidated, but which are a promising novel routes to be explored. This study revealed the radiation resistance of Arthrospira, and the molecular systems involved, paving the way for its further and better exploitation.
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Affiliation(s)
- Hanène Badri
- Expert Group for Molecular and Cellular Biology, Belgian Nuclear Research Center SCK•CEN, Mol, Belgium.,Proteomics and Microbiology Group, Research Institute for Biosciences, University of Mons, Mons, Belgium
| | - Pieter Monsieurs
- Expert Group for Molecular and Cellular Biology, Belgian Nuclear Research Center SCK•CEN, Mol, Belgium
| | - Ilse Coninx
- Expert Group for Molecular and Cellular Biology, Belgian Nuclear Research Center SCK•CEN, Mol, Belgium
| | - Ruddy Wattiez
- Proteomics and Microbiology Group, Research Institute for Biosciences, University of Mons, Mons, Belgium
| | - Natalie Leys
- Expert Group for Molecular and Cellular Biology, Belgian Nuclear Research Center SCK•CEN, Mol, Belgium
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Kanwal S, Khetkorn W, Incharoensakdi A. GABA Accumulation in Response to Different Nitrogenous Compounds in Unicellular Cyanobacterium Synechocystis sp. PCC 6803. Curr Microbiol 2014; 70:96-102. [DOI: 10.1007/s00284-014-0687-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 07/22/2014] [Indexed: 10/24/2022]
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Osanai T, Oikawa A, Iijima H, Kuwahara A, Asayama M, Tanaka K, Ikeuchi M, Saito K, Hirai MY. Metabolomic analysis reveals rewiring of Synechocystis sp. PCC 6803 primary metabolism by ntcA overexpression. Environ Microbiol 2014; 16:3304-17. [PMID: 25039649 DOI: 10.1111/1462-2920.12554] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2014] [Accepted: 06/30/2014] [Indexed: 11/26/2022]
Abstract
NtcA is a cAMP receptor protein-type transcription factor conserved among cyanobacteria and is essential for gene expression in response to nitrogen status. NtcA has been widely studied; however, no metabolomic analysis has been conducted using the ntcA mutant. Here, we generated a strain that overexpresses ntcA in Synechocystis sp. PCC 6803, named NOX10, and performed physiological, transcriptomic and metabolomic analyses. NOX10 grew faster than the wild-type strain under photoautotrophic conditions, but slower under light-activated heterotrophic conditions. Transcriptome analysis revealed that the expression of genes related to primary metabolism was altered by ntcA overexpression particularly under nitrogen-depleted conditions. Metabolomic analysis revealed that metabolite levels in sugar, purine/pyrimidine nucleotide, organic acid and amino acid metabolism were widely altered by ntcA overexpression. The protein levels of nitrogen-regulated transcriptional regulators were altered by ntcA overexpression during nitrogen starvation. These results demonstrate the alteration of primary metabolism by genetic engineering of NtcA, and they contribute to the current understanding of metabolic regulation of unicellular cyanobacteria.
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Affiliation(s)
- Takashi Osanai
- RIKEN, Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan; Japan Science and Technology Agency (JST), PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
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25
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Verspagen JMH, Van de Waal DB, Finke JF, Visser PM, Huisman J. Contrasting effects of rising CO2 on primary production and ecological stoichiometry at different nutrient levels. Ecol Lett 2014; 17:951-60. [PMID: 24813339 DOI: 10.1111/ele.12298] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 04/11/2014] [Accepted: 04/18/2014] [Indexed: 11/29/2022]
Abstract
Although rising CO2 concentrations are thought to promote the growth and alter the carbon : nutrient stoichiometry of primary producers, several studies have reported conflicting results. To reconcile these contrasting results, we tested the following hypotheses: rising CO2 levels (1) will increase phytoplankton biomass more at high nutrient loads than at low nutrient loads, but (2) will increase their carbon : nutrient stoichiometry more at low than at high nutrient loads. We formulated a mathematical model to predict dynamic changes in phytoplankton population density, elemental stoichiometry and inorganic carbon chemistry in response to rising CO2 . The model was tested in chemostat experiments with the freshwater cyanobacterium Microcystis aeruginosa. The model predictions and experimental results confirmed the hypotheses. Our findings provide a novel theoretical framework to understand and predict effects of rising CO2 concentrations on primary producers and their nutritional quality as food for herbivores under different nutrient conditions.
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Affiliation(s)
- Jolanda M H Verspagen
- Department of Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94248, 1090 GE, Amsterdam, The Netherlands
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26
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Huang S, Chen L, Te R, Qiao J, Wang J, Zhang W. Complementary iTRAQ proteomics and RNA-seq transcriptomics reveal multiple levels of regulation in response to nitrogen starvation in Synechocystis sp. PCC 6803. MOLECULAR BIOSYSTEMS 2014; 9:2565-74. [PMID: 23942477 DOI: 10.1039/c3mb70188c] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Sequential adaptation to environmental stress needs complex regulation at different cellular levels in cyanobacteria. To uncover the regulatory mechanism in response to nitrogen starvation, we investigated the genome-wide correlation between protein abundance and gene expression in a model cyanobacterium Synechocystis sp. PCC 6803 using complementary quantitative iTRAQ proteomics and RNA-seq transcriptomics. Consistent with the cell growth inhibition, proteomic analysis indicated phase-dependent down-regulation of proteins related to nitrogen metabolism, ribosome complexes, glycolysis pathway and tricarboxylic acid (TCA) cycles by nitrogen starvation. Transcriptomic analysis also showed that genes related to "Photosynthesis", "Protein synthesis" and "Energy metabolism" were significantly down-regulated by nitrogen starvation. Interestingly, the concordance between protein abundances and their corresponding mRNAs exhibited a functional categories-dependent pattern, with some categories, such as "Protein synthesis" and "Energy metabolism", having a relatively high correlation, while others even with numerous discordant changes in protein-mRNA pairs, indicated divergent regulation of transcriptional and post-transcriptional processes. In particular, an increased abundance of proteins related to "Photosynthesis" upon nitrogen starvation was found to be reversely correlated with the down-regulation of their corresponding mRNAs. In addition, two metabolic modules highly correlated with nitrogen starvation were identified by a co-expression network analysis, and were found to contain mostly photosynthetic proteins and hypothetical proteins, respectively. We further confirmed the involvement of the photosynthetic genes in nitrogen starvation tolerance by constructing and analyzing the psbV gene deletion mutant.
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Affiliation(s)
- Siqiang Huang
- School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, P.R. China.
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Rabouille S, Van de Waal DB, Matthijs HCP, Huisman J. Nitrogen fixation and respiratory electron transport in the cyanobacterium Cyanothece under different light/dark cycles. FEMS Microbiol Ecol 2013; 87:630-8. [PMID: 24236731 DOI: 10.1111/1574-6941.12251] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 10/24/2013] [Accepted: 11/11/2013] [Indexed: 11/30/2022] Open
Abstract
Incompatibility of nitrogen fixation and oxygen production compels unicellular diazotrophic cyanobacteria to perform photosynthesis during daytime and restrict nitrogen fixation to nighttime. The marine diazotroph Cyanothece BG 043511 was grown in continuous culture under three light/dark regimes (16L : 8D, 12L : 12D, and 8L : 16D h); we monitored nitrogen fixation and potential photosynthetic efficiency simultaneously online to reveal how their temporal separation is affected by different LD regimes. An increase in nitrogen fixation rate at night coincided with a rise in pulse-amplitude modulated fluorescence, indicating that the enhanced respiratory electron transport to fuel diazotrophy affects the oxidation state of the plastoquinone pool. This may offer an alternative approach to assess instantaneous nitrogen fixation activity. Regardless of photoperiod, the maximum rate of nitrogen fixation was conserved at about 20 h after the onset of the light. Consequently, nitrogen fixation rates peaked at different moments in the dark: relatively early in the 16L : 8D cycle, at midnight in 12L : 12D, and relatively late in 8L : 16D. Under 16L : 8D, nitrogen fixation extended into the light, demonstrating the functional plasticity of nitrogen fixation in Cyanothece. Highest daily amounts of nitrogen fixed were obtained in 12L : 12D, which is consistent with the natural LD cycle of subtropical latitudes in which Cyanothece thrives.
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Affiliation(s)
- Sophie Rabouille
- Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands; UPMC Univ Paris 06, UMR 7093, LOV, Observatoire océanologique, Villefranche/mer, France; LOV, Observatoire océanologique, CNRS, UMR 7093, Villefranche/mer, France
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Nagarajan S, Srivastava S, Sherman LA. Essential role of the plasmid hik31 operon in regulating central metabolism in the dark in Synechocystis sp. PCC 6803. Mol Microbiol 2013; 91:79-97. [PMID: 24237382 DOI: 10.1111/mmi.12442] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/24/2013] [Indexed: 12/13/2022]
Abstract
The plasmid hik31 operon (P3, slr6039-slr6041) is located on the pSYSX plasmid in Synechocystis sp. PCC 6803. A P3 mutant (ΔP3) had a growth defect in the dark and a pigment defect that was worsened by the addition of glucose. The glucose defect was from incomplete metabolism of the substrate, was pH dependent, and completely overcome by the addition of bicarbonate. Addition of organic carbon and nitrogen sources partly alleviated the defects of the mutant in the dark. Electron micrographs of the mutant revealed larger cells with division defects, glycogen limitation, lack of carboxysomes, deteriorated thylakoids and accumulation of polyhydroxybutyrate and cyanophycin. A microarray experiment over two days of growth in light-dark plus glucose revealed downregulation of several photosynthesis, amino acid biosynthesis, energy metabolism genes; and an upregulation of cell envelope and transport and binding genes in the mutant. ΔP3 had an imbalance in carbon and nitrogen levels and many sugar catabolic and cell division genes were negatively affected after the first dark period. The mutant suffered from oxidative and osmotic stress, macronutrient limitation, and an energy deficit. Therefore, the P3 operon is an important regulator of central metabolism and cell division in the dark.
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Affiliation(s)
- Sowmya Nagarajan
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA
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Osanai T, Kuwahara A, Iijima H, Toyooka K, Sato M, Tanaka K, Ikeuchi M, Saito K, Hirai MY. Pleiotropic effect of sigE over-expression on cell morphology, photosynthesis and hydrogen production in Synechocystis sp. PCC 6803. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2013; 76:456-65. [PMID: 23941239 DOI: 10.1111/tpj.12310] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 08/07/2013] [Accepted: 08/09/2013] [Indexed: 05/04/2023]
Abstract
Over-expression of sigE, a gene encoding an RNA polymerase sigma factor in the unicellular cyanobacterium Synechocystis sp. PCC 6803, is known to activate sugar catabolism and bioplastic production. In this study, we investigated the effects of sigE over-expression on cell morphology, photosynthesis and hydrogen production in this cyanobacterium. Transmission electron and scanning probe microscopic analyses revealed that sigE over-expression increased the cell size, possibly as a result of aberrant cell division. Over-expression of sigE reduced respiration and photosynthesis activities via changes in gene expression and chlorophyll fluorescence. Hydrogen production under micro-oxic conditions is enhanced in sigE over-expressing cells. Despite these pleiotropic phenotypes, the sigE over-expressing strain showed normal cell viability under both nitrogen-replete and nitrogen-depleted conditions. These results provide insights into the inter-relationship among metabolism, cell morphology, photosynthesis and hydrogen production in this unicellular cyanobacterium.
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Affiliation(s)
- Takashi Osanai
- RIKEN Plant Science Center, 1-7-22, Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan; Japan Science and Technology Agency, PRESTO, 4-1-8, Honcho, Kawaguchi, Saitama, 332-0012, Japan
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Schwarz D, Schubert H, Georg J, Hess WR, Hagemann M. The gene sml0013 of Synechocystis species strain PCC 6803 encodes for a novel subunit of the NAD(P)H oxidoreductase or complex I that is ubiquitously distributed among Cyanobacteria. PLANT PHYSIOLOGY 2013; 163:1191-202. [PMID: 24089436 PMCID: PMC3813643 DOI: 10.1104/pp.113.224287] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 10/01/2013] [Indexed: 05/21/2023]
Abstract
The NAD(P)H oxidoreductase or complex I (NDH1) complex participates in many processes such as respiration, cyclic electron flow, and inorganic carbon concentration in the cyanobacterial cell. Despite immense progress in our understanding of the structure-function relation of the cyanobacterial NDH1 complex, the subunits catalyzing NAD(P)H docking and oxidation are still missing. The gene sml0013 of Synechocystis 6803 encodes for a small protein of unknown function for which homologs exist in all completely known cyanobacterial genomes. The protein exhibits weak similarities to the NDH-dependent flow6 (NDF6) protein, which was reported from Arabidopsis (Arabidopsis thaliana) chloroplasts as a NDH subunit. An sml0013 inactivation mutant of Synechocystis 6803 was generated and characterized. It showed only weak differences regarding growth and pigmentation in various culture conditions; most remarkably, it exhibited a glucose-sensitive phenotype in the light. The genome-wide expression pattern of the Δsml0013::Km mutant was almost identical to the wild type when grown under high CO2 conditions as well as after shifts to low CO2 conditions. However, measurements of the photosystem I redox kinetic in cells of the Δsml0013::Km mutant revealed differences, such as a decreased capability of cyclic electron flow as well as electron flow into respiration in comparison with the wild type. These results suggest that the Sml0013 protein (named NdhP) represents a novel subunit of the cyanobacterial NDH1 complex, mediating its coupling either to the respiratory or the photosynthetic electron flow.
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Zhu H, Ren X, Wang J, Song Z, Shi M, Qiao J, Tian X, Liu J, Chen L, Zhang W. Integrated OMICS guided engineering of biofuel butanol-tolerance in photosynthetic Synechocystis sp. PCC 6803. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:106. [PMID: 23883549 PMCID: PMC3726282 DOI: 10.1186/1754-6834-6-106] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Accepted: 07/23/2013] [Indexed: 05/03/2023]
Abstract
BACKGROUND Photosynthetic cyanobacteria have been recently proposed as a 'microbial factory' to produce butanol due to their capability to utilize solar energy and CO2 as the sole energy and carbon sources, respectively. However, to improve the productivity, one key issue needed to be addressed is the low tolerance of the photosynthetic hosts to butanol. RESULTS In this study, we first applied a quantitative transcriptomics approach with a next-generation RNA sequencing technology to identify gene targets relevant to butanol tolerance in a model cyanobacterium Synechocystis sp. PCC 6803. The results showed that 278 genes were induced by the butanol exposure at all three sampling points through the growth time course. Genes encoding heat-shock proteins, oxidative stress related proteins, transporters and proteins involved in common stress responses, were induced by butanol exposure. We then applied GC-MS based metabolomics analysis to determine the metabolic changes associated with the butanol exposure. The results showed that 46 out of 73 chemically classified metabolites were differentially regulated by butanol treatment. Notably, 3-phosphoglycerate, glycine, serine and urea related to general stress responses were elevated in butanol-treated cells. To validate the potential targets, we constructed gene knockout mutants for three selected gene targets. The comparative phenotypic analysis confirmed that these genes were involved in the butanol tolerance. CONCLUSION The integrated OMICS analysis provided a comprehensive view of the complicated molecular mechanisms employed by Synechocystis sp. PCC 6803 against butanol stress, and allowed identification of a series of potential gene candidates for tolerance engineering in cyanobacterium Synechocystis sp. PCC 6803.
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Affiliation(s)
- Hongji Zhu
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, P.R. China
- Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin 300072, P.R. China
| | - Xiaoyue Ren
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, P.R. China
- Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin 300072, P.R. China
| | - Jiangxin Wang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, P.R. China
- Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin 300072, P.R. China
| | - Zhongdi Song
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, P.R. China
- Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin 300072, P.R. China
| | - Mengliang Shi
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, P.R. China
- Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin 300072, P.R. China
| | - Jianjun Qiao
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, P.R. China
- Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin 300072, P.R. China
| | - Xiaoxu Tian
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, P.R. China
- Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin 300072, P.R. China
| | - Jie Liu
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, P.R. China
- Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin 300072, P.R. China
| | - Lei Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, P.R. China
- Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin 300072, P.R. China
| | - Weiwen Zhang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, P.R. China
- Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin 300072, P.R. China
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Osanai T, Oikawa A, Shirai T, Kuwahara A, Iijima H, Tanaka K, Ikeuchi M, Kondo A, Saito K, Hirai MY. Capillary electrophoresis-mass spectrometry reveals the distribution of carbon metabolites during nitrogen starvation in Synechocystis sp. PCC 6803. Environ Microbiol 2013; 16:512-24. [PMID: 23796428 DOI: 10.1111/1462-2920.12170] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2013] [Revised: 05/23/2013] [Accepted: 05/25/2013] [Indexed: 12/01/2022]
Abstract
Nitrogen availability is one of the most important factors for the survival of cyanobacteria. Previous studies on Synechocystis revealed a contradictory situation with regard to metabolism during nitrogen starvation; that is, glycogen accumulated even though the expressions of sugar catabolic genes were widely upregulated. Here, we conducted transcript and metabolomic analyses using capillary electrophoresis-mass spectrometry on Synechocystis sp. PCC 6803 under nitrogen starvation. The levels of some tricarboxylic acid cycle intermediates (succinate, malate and fumarate) were greatly increased by nitrogen deprivation. Purine and pyrimidine nucleotides were markedly downregulated under nitrogen depletion. The levels of 19 amino acids changed under nitrogen deprivation, especially those of amino acids synthesized from pyruvate and phosphoenolpyruvate, which showed marked increases. Liquid chromatography-mass spectrometry analysis demonstrated that the amount of NADPH and the NADPH/NADH ratio decreased under nitrogen depletion. These data demonstrate that there are increases in not only glycogen but also in metabolites downstream of sugar catabolism in Synechocystis sp. PCC 6803 under nitrogen starvation, resolving the contradiction between glycogen accumulation and induction of sugar catabolic gene expression in this unicellular cyanobacterium.
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Affiliation(s)
- Takashi Osanai
- RIKEN Plant Science Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan; PRESTO, Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
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Schwarzenberger A, Sadler T, Von Elert E. Effect of nutrient limitation of cyanobacteria on protease inhibitor production and fitness of Daphnia magna. J Exp Biol 2013; 216:3649-55. [DOI: 10.1242/jeb.088849] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Summary
Herbivore-plant interactions have been well studied in both terrestrial and aquatic ecosystems as they are crucial for the trophic transfer of energy and matter. In nutrient-rich freshwater ecosystems, the interaction between primary producers and herbivores is to a large extent represented by Daphnia and cyanobacteria. The occurrence of cyanobacterial blooms in lakes and ponds has, at least partly, been attributed to cyanotoxins, which negatively affect the major grazer of planktonic cyanobacteria, i.e. Daphnia. Among these cyanotoxins are the wide-spread protease inhibitors. These inhibitors have been shown (both in vitro and in situ) to inhibit the most important group of digestive proteases in the gut of Daphnia, i.e. trypsins and chymotrypsins, and to reduce Daphnia growth. In this study we grew cultures of the cyanobacterium Microcystis aeruginosa strain BM25 on nutrient replete, N-depleted or P-depleted medium. We identified three different micropeptins to be the cause for the inhibitory activity of BM25 against chymotrypsins. The micropeptin content depended on nutrient availability: Whereas N-limitation led to a lower concentration of micropeptins per biomass, P-limitation resulted in a higher production of these chymotrypsin inhibitors. The altered micropeptin content of BM25 was accompanied by changed effects on the fitness of Daphnia: A higher content of micropeptins led to lower IC50 values for Daphnia gut proteases and vice-versa. Following expectations, the lower content of micropeptins in the N-depleted BM25 caused higher somatic growth of Daphnia. Therefore, protease inhibitors can be regarded as a nutrient-dependent defence against grazers. Interestingly, although the P-limitation of the cyanobacterium led to a higher micropeptin content, high growth of D. magna was observed when they were fed with P-depleted BM25. This might be due to reduced digestibility of P-depleted cells with putatively thick mucilaginous sheaths. These findings indicate that both the grazer and the cyanobacterium benefit from P-reduction in light of digestibility and growth inhibition, which is an interesting starting point for further studies.
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Gründel M, Scheunemann R, Lockau W, Zilliges Y. Impaired glycogen synthesis causes metabolic overflow reactions and affects stress responses in the cyanobacterium Synechocystis sp. PCC 6803. Microbiology (Reading) 2012; 158:3032-3043. [DOI: 10.1099/mic.0.062950-0] [Citation(s) in RCA: 187] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Marianne Gründel
- Humboldt-Universität zu Berlin, Institute of Biology/Biochemistry of Plants, Chausseestr. 117, 10115 Berlin, Germany
| | - Ramon Scheunemann
- Humboldt-Universität zu Berlin, Institute of Biology/Biochemistry of Plants, Chausseestr. 117, 10115 Berlin, Germany
| | - Wolfgang Lockau
- Humboldt-Universität zu Berlin, Institute of Biology/Biochemistry of Plants, Chausseestr. 117, 10115 Berlin, Germany
| | - Yvonne Zilliges
- Humboldt-Universität zu Berlin, Institute of Biology/Biochemistry of Plants, Chausseestr. 117, 10115 Berlin, Germany
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Salomon E, Bar-Eyal L, Sharon S, Keren N. Balancing photosynthetic electron flow is critical for cyanobacterial acclimation to nitrogen limitation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012. [PMID: 23201479 DOI: 10.1016/j.bbabio.2012.11.010] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Nitrogen limitation forces photosynthetic organisms to reallocate available nitrogen to essential functions. At the same time, it increases the probability of photo-damage by limiting the rate of energy-demanding metabolic processes, downstream of the photosynthetic apparatus. Non-diazotrophic cyanobacteria cope with this situation by decreasing the size of their phycobilisome antenna and by modifying their photosynthetic apparatus. These changes can serve two purposes: to provide extra amino-acids and to decrease excitation pressure. We examined the effects of nitrogen limitation on the form and function of the photosynthetic apparatus. Our aim was to study which of the two demands serve as the driving force for the remodeling of the photosynthetic apparatus, under different growth conditions. We found that a drastic reduction in light intensity allowed cells to maintain a more functional photosynthetic apparatus: the phycobilisome antenna was bigger, the activity of both photosystems was higher and the levels of photosystem (PS) proteins were higher. Pre-acclimating cells to Mn limitation, under which the activity of both PSI and PSII is diminished, results in a very similar response. The rate of PSII photoinhibition, in nitrogen limited cells, was found to be directly related to the activity of the photosynthetic apparatus. These data indicate that, under our experimental conditions, photo-damage avoidance was the more prominent determinant during the acclimation process. The combinations of limiting factors tested here is by no means artificial. Similar scenarios can take place under environmental conditions and should be taken into account when estimating nutrient limitations in nature.
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Affiliation(s)
- Eitan Salomon
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
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Krasikov V, Aguirre von Wobeser E, Dekker HL, Huisman J, Matthijs HCP. Time-series resolution of gradual nitrogen starvation and its impact on photosynthesis in the cyanobacterium Synechocystis PCC 6803. PHYSIOLOGIA PLANTARUM 2012; 145:426-439. [PMID: 22289076 DOI: 10.1111/j.1399-3054.2012.01585.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Sequential adaptation to nitrogen deprivation and ultimately to full starvation requires coordinated adjustment of cellular functions. We investigated changes in gene expression and cell physiology of the cyanobacterium Synechocystis PCC 6803 during 96 h of nitrogen starvation. During the first 6 h, the transcriptome showed activation of nitrogen uptake and assimilation systems and of the core nitrogen and carbon assimilation regulators. However, the nitrogen-deprived cells still grew at the same rate as the control and even showed transiently increased expression of phycobilisome genes. After 12 h, cell growth decreased and chlorosis started with degradation of the nitrogen-rich phycobilisomes. During this phase, the transcriptome showed suppression of genes for phycobilisomes, for carbon fixation and for de novo protein synthesis. Interestingly, photosynthetic activity of both photosystem I (PSI) and photosystem II was retained quite well. Excess electrons were quenched by the induction of terminal oxidase and hydrogenase genes, compensating for the diminished carbon fixation and nitrate reduction activity. After 48 h, the cells ceased most activities. A marked exception was the retained PSI gene transcription, possibly this supports the viability of Synechocystis cells and enables rapid recovery after relieving from nitrogen starvation. During early recovery, many genes changed expression, supporting the resumed cellular activity. In total, our results distinguished three phases during gradual nitrogen depletion: (1) an immediate response, (2) short-term acclimation and (3) long-term survival. This shows that cyanobacteria respond to nitrogen starvation by a cascade of physiological adaptations reflected by numerous changes in the transcriptome unfolding at different timescales.
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Affiliation(s)
- Vladimir Krasikov
- Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94248, 1090 GE Amsterdam, The Netherlands
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Brauer VS, Stomp M, Huisman J. The nutrient-load hypothesis: patterns of resource limitation and community structure driven by competition for nutrients and light. Am Nat 2012; 179:721-40. [PMID: 22617261 DOI: 10.1086/665650] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Resource competition theory predicts that the outcome of competition for two nutrients depends on the ratio at which these nutrients are supplied. Yet there is considerable debate whether nutrient ratios or absolute nutrient loads determine the species composition of phytoplankton and plant communities. Here we extend the classical resource competition model for two nutrients by including light as additional resource. Our results suggest the nutrient-load hypothesis, which predicts that nutrient ratios determine the species composition in oligotrophic environments, whereas nutrient loads are decisive in eutrophic environments. The underlying mechanism is that nutrient enrichment shifts the species interactions from competition for nutrients to competition for light, which favors the dominance of superior light competitors overshadowing all other species. Intermediate nutrient loads can generate high biodiversity through a fine-grained patchwork of two-species and three-species coexistence equilibria. Depending on the species traits, however, competition for nutrients and light may also produce multiple alternative stable states, suppressing the predictability of the species composition. The nutrient-load hypothesis offers a solution for several discrepancies between classical resource competition theory and field observations, explains why eutrophication often leads to diversity loss, and provides a simple conceptual framework for patterns of biodiversity and community structure observed in nature.
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Affiliation(s)
- Verena S Brauer
- Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94248, 1090 GE Amsterdam, The Netherlands.
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Hackenberg C, Huege J, Engelhardt A, Wittink F, Laue M, Matthijs HCP, Kopka J, Bauwe H, Hagemann M. Low-carbon acclimation in carboxysome-less and photorespiratory mutants of the cyanobacterium Synechocystis sp. strain PCC 6803. Microbiology (Reading) 2012; 158:398-413. [DOI: 10.1099/mic.0.054544-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Affiliation(s)
- Claudia Hackenberg
- Universität Rostock, Institut für Biowissenschaften, Pflanzenphysiologie, Albert-Einstein-Str. 3, D-18059 Rostock, Germany
| | - Jan Huege
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Golm, Germany
| | - Annerose Engelhardt
- Universität Rostock, Institut für Biowissenschaften, Pflanzenphysiologie, Albert-Einstein-Str. 3, D-18059 Rostock, Germany
| | - Floyd Wittink
- Microarray Department, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098XH Amsterdam, The Netherlands
| | - Michael Laue
- Universität Rostock, Institut für Pathologie, Elektronenmikroskopisches Zentrum, Strempelstr. 14, D-18055 Rostock, Germany
| | - Hans C. P. Matthijs
- Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Science Park 904, 1098XH Amsterdam, The Netherlands
| | - Joachim Kopka
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Golm, Germany
| | - Hermann Bauwe
- Universität Rostock, Institut für Biowissenschaften, Pflanzenphysiologie, Albert-Einstein-Str. 3, D-18059 Rostock, Germany
| | - Martin Hagemann
- Universität Rostock, Institut für Biowissenschaften, Pflanzenphysiologie, Albert-Einstein-Str. 3, D-18059 Rostock, Germany
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