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Roncero-Ramos B, Savaglia V, Durieu B, Van de Vreken I, Richel A, Wilmotte A. Ecophysiological and genomic approaches to cyanobacterial hardening for restoration. JOURNAL OF PHYCOLOGY 2024; 60:465-482. [PMID: 38373045 DOI: 10.1111/jpy.13436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 12/15/2023] [Accepted: 12/15/2023] [Indexed: 02/20/2024]
Abstract
Cyanobacteria inhabit extreme environments, including drylands, providing multiple benefits to the ecosystem. Soil degradation in warm drylands is increasing due to land use intensification. Restoration methods adapted to the extreme stress in drylands are being developed, such as cyanobacteria inoculation to recover biocrusts. For this type of restoration method to be a success, it is crucial to optimize the survival of inoculated cyanobacteria in the field. One strategy is to harden them to be acclimated to stressful conditions after laboratory culturing. Here, we analyzed the genome and ecophysiological response to osmotic desiccation and UVR stresses of an Antarctic cyanobacterium, Stenomitos frigidus ULC029, which is closely related to other cyanobacteria from warm and cold dryland soils. Chlorophyll a concentrations showed that preculturing ULC029 under moderate osmotic stress improved its survival during an assay of desiccation plus rehydration under UVR. Additionally, its sequential exposure to these stress factors increased the production of exopolysaccharides, carotenoids, and scytonemin. Desiccation, but not osmotic stress, increased the concentrations of the osmoprotectants trehalose and sucrose. However, osmotic stress might induce the production of other osmoprotectants, for which the complete pathways were observed in the ULC029 genome. In total, 140 genes known to be involved in stress resistance were annotated. Here, we confirm that the sequential application of moderate osmotic stress and dehydration could improve cyanobacterial hardening for soil restoration by inducing several resistance mechanisms. We provide a high-quality genome of ULC029 and a description of the main resistance mechanisms (i.e., production of exopolysaccharides, osmoprotectants, chlorophyll, and carotenoids; DNA repair; and oxidative stress protection).
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Affiliation(s)
- Beatriz Roncero-Ramos
- InBios-Molecular Diversity and Ecology of Cyanobacteria, University of Liège, Liege, Belgium
- Departamento de Biología Vegetal y Ecología, Universidad de Sevilla, Sevilla, Spain
| | - Valentina Savaglia
- InBios-Molecular Diversity and Ecology of Cyanobacteria, University of Liège, Liege, Belgium
- Laboratory of Protistology & Aquatic Ecology, Ghent University, Ghent, Belgium
| | - Benoit Durieu
- InBios-Molecular Diversity and Ecology of Cyanobacteria, University of Liège, Liege, Belgium
| | | | - Aurore Richel
- TERRA-Biomass and Green Technologies, University of Liège, Gembloux, Belgium
| | - Annick Wilmotte
- InBios-Molecular Diversity and Ecology of Cyanobacteria, University of Liège, Liege, Belgium
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Mudtham NA, Promariya A, Duangsri C, Maneeruttanarungroj C, Ngamkala S, Akrimajirachoote N, Powtongsook S, Salminen TA, Raksajit W. Exogenous Trehalose Improves Growth, Glycogen and Poly-3-Hydroxybutyrate (PHB) Contents in Photoautotrophically Grown Arthrospira platensis under Nitrogen Deprivation. BIOLOGY 2024; 13:127. [PMID: 38392345 PMCID: PMC10886759 DOI: 10.3390/biology13020127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 02/09/2024] [Accepted: 02/16/2024] [Indexed: 02/24/2024]
Abstract
Glycogen and poly-3-hydroxybutyrate (PHB) are excellent biopolymer products from cyanobacteria. In this study, we demonstrate that nitrogen metabolism is positively influenced by the exogenous application of trehalose (Tre) in Arthrospira platensis under nitrogen-deprived (-N) conditions. Cells were cultivated photoautotrophically for 5 days under -N conditions, with or without the addition of exogenous Tre. The results revealed that biomass and chlorophyll-a content of A. platensis experienced enhancement with the addition of 0.003 M and 0.03 M Tre in the -N medium after one day, indicating relief from growth inhibition caused by nitrogen deprivation. The highest glycogen content (54.09 ± 1.6% (w/w) DW) was observed in cells grown for 2 days under the -N + 0.003 M Tre condition (p < 0.05), while the highest PHB content (15.2 ± 0.2% (w/w) DW) was observed in cells grown for 3 days under the -N + 0.03 M Tre condition (p < 0.05). The RT-PCR analysis showed a significant increase in glgA and phaC transcript levels, representing approximately 1.2- and 1.3-fold increases, respectively, in A. platensis grown under -N + 0.003 M Tre and -N + 0.03 M Tre conditions. This was accompanied by the induction of enzyme activities, including glycogen synthase and PHA synthase with maximal values of 89.15 and 0.68 µmol min-1 mg-1 protein, respectively. The chemical structure identification of glycogen and PHB from A. platensis was confirmed by FTIR and NMR analysis. This research represents the first study examining the performance of trehalose in promoting glycogen and PHB production in cyanobacteria under nitrogen-deprived conditions.
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Affiliation(s)
- Nat-Anong Mudtham
- Program of Animal Health Technology, Department of Veterinary Nursing, Faculty of Veterinary Technology, Kasetsart University, Bangkok 10900, Thailand
| | - Authen Promariya
- Program of Animal Health Technology, Department of Veterinary Nursing, Faculty of Veterinary Technology, Kasetsart University, Bangkok 10900, Thailand
| | - Chanchanok Duangsri
- Department of Animal Science, Faculty of Agricultural Technology and Agro-Industry, Rajamangala University of Technology Suvarnabhumi, Phranakhon Si Ayutthaya 13000, Thailand
| | - Cherdsak Maneeruttanarungroj
- Department of Biology, School of Science, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand
| | - Suchanit Ngamkala
- Program of Animal Health Technology, Department of Veterinary Nursing, Faculty of Veterinary Technology, Kasetsart University, Bangkok 10900, Thailand
| | | | - Sorawit Powtongsook
- Center of Excellence for Marine Biotechnology, Department of Marine Science, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- National Center for Genetic Engineering and Biotechnology (BIOTEC), Pathum Thani 12120, Thailand
| | - Tiina A Salminen
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Tykistökatu 6 A, FI-20520 Turku, Finland
| | - Wuttinun Raksajit
- Program of Animal Health Technology, Department of Veterinary Nursing, Faculty of Veterinary Technology, Kasetsart University, Bangkok 10900, Thailand
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Santos-Merino M, Yun L, Ducat DC. Cyanobacteria as cell factories for the photosynthetic production of sucrose. Front Microbiol 2023; 14:1126032. [PMID: 36865782 PMCID: PMC9971976 DOI: 10.3389/fmicb.2023.1126032] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 01/24/2023] [Indexed: 02/16/2023] Open
Abstract
Biofuels and other biologically manufactured sustainable goods are growing in popularity and demand. Carbohydrate feedstocks required for industrial fermentation processes have traditionally been supplied by plant biomass, but the large quantities required to produce replacement commodity products may prevent the long-term feasibility of this approach without alternative strategies to produce sugar feedstocks. Cyanobacteria are under consideration as potential candidates for sustainable production of carbohydrate feedstocks, with potentially lower land and water requirements relative to plants. Several cyanobacterial strains have been genetically engineered to export significant quantities of sugars, especially sucrose. Sucrose is not only naturally synthesized and accumulated by cyanobacteria as a compatible solute to tolerate high salt environments, but also an easily fermentable disaccharide used by many heterotrophic bacteria as a carbon source. In this review, we provide a comprehensive summary of the current knowledge of the endogenous cyanobacterial sucrose synthesis and degradation pathways. We also summarize genetic modifications that have been found to increase sucrose production and secretion. Finally, we consider the current state of synthetic microbial consortia that rely on sugar-secreting cyanobacterial strains, which are co-cultivated alongside heterotrophic microbes able to directly convert the sugars into higher-value compounds (e.g., polyhydroxybutyrates, 3-hydroxypropionic acid, or dyes) in a single-pot reaction. We summarize recent advances reported in such cyanobacteria/heterotroph co-cultivation strategies and provide a perspective on future developments that are likely required to realize their bioindustrial potential.
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Affiliation(s)
- María Santos-Merino
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
| | - Lisa Yun
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, United States
| | - Daniel C. Ducat
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, United States
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Production of Arthrospira platensis: Effects on Growth and Biochemical Composition of Long-Term Acclimatization at Different Salinities. Bioengineering (Basel) 2023; 10:bioengineering10020233. [PMID: 36829727 PMCID: PMC9952471 DOI: 10.3390/bioengineering10020233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/14/2023] [Accepted: 02/06/2023] [Indexed: 02/12/2023] Open
Abstract
Arthrospira platensis is an edible cyanobacterium with high nutritional value. Even though A. platensis is not a marine species, it can be adapted to higher salinities, a strategy that could allow mass cultivation using brackish or saline water. In this work A. platensis was long-term adapted at different salinities (5-60 g/L NaCl added as natural sea salt) to evaluate the growth and biochemical composition of the biomass produced. Biomass production was enhanced in salinity up to 40 g/L NaCl, while at 60 g/L NaCl biomass production slightly decreased. However, it displayed higher values compared to the conventional Zarrouk growth medium. By increasing the salinity, carbohydrate content increases, while proteins, phycocyanin, carotenoids, and total phenolics decreased. Biomass content in lipids, and chlorophyll along with the antioxidant capacity of extracts, was not significantly affected. A. platensis tended to increase the unsaturated fatty acids, while amino acid composition was not significantly affected by the increased salinity. However, in vitro protein digestibility was negatively affected when salinity was above 20 g/L NaCl. It was macroscopically observed that trichomes were longer at higher salinities, and especially at 40 g/L NaCl. The results suggest that A. platensis when acclimated in long-term can be grown successfully at various salinities.
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Roncero-Ramos B, Román JR, Acién G, Cantón Y. Towards large scale biocrust restoration: Producing an efficient and low-cost inoculum of N-fixing cyanobacteria. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 848:157704. [PMID: 35908695 DOI: 10.1016/j.scitotenv.2022.157704] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 07/04/2022] [Accepted: 07/25/2022] [Indexed: 06/15/2023]
Abstract
Dryland soil degradation is increasing due to global change and traditional restoration methods are not successful due to water scarcity. Thus, an alternative technology based on inoculating biocrust-forming cyanobacteria on degraded soils has emerged. Biocrusts are communities of mosses, lichens, cyanobacteria or fungi that colonize soil surface forming a stable and fertile layer. Previous studies have shown the benefits of inoculating cyanobacteria to restore soils at a small scale. However, to face field restoration projects, it is necessary to produce high quantities of biomass at an affordable cost. In this work, we analyze if the previously tested cyanobacteria Scytonema hyalinum, Tolypothrix distorta (heterocystous strains) and Trichocoleus desertorum (a bundle-forming one) can be produced with agricultural fertilizers. Different culture media were used: two containing pure chemicals (BG11 and BG110, this N-free medium was used just for heterocystous strains) and two containing fertilizers (BG11-F and MM-F). The performance of the cultures was monitored by measuring the biomass concentration and photosynthetic stress. Afterwards, we analyzed their capacity to induce biocrusts and improve soil properties by inoculating the biomass on a mine substrate indoors and measuring, three months later, the albedo, chlorophyll a and organic carbon content. Results show that the bundle-forming cyanobacterium was unable to grow in the media tested, whereas both heterocystous cyanobacteria grew in all of them and induced the formation of biocrusts improving the organic carbon substrate content. The best results for S. hyalinum were found using the MM-F medium, and for T. distorta using a medium containing pure chemicals (BG11). However, results were also positive when using a medium containing fertilizers (BG11-F). Thus, agricultural fertilizers can be used to undertake the production of heterocystous cyanobacteria for large scale restoration in drylands. On the other hand, more research is needed to find sustainable techniques to produce biomass of bundle-forming cyanobacteria.
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Affiliation(s)
- Beatriz Roncero-Ramos
- Department of Life Sciences, InBios-Center for Protein Engineering, University of Liège, Belgium; Agronomy Department, University of Almería, Spain.
| | - José Raúl Román
- Agronomy Department, University of Almería, Spain; Department of Ecosystem Science and Management, The Pennsylvania State University, State College, PA, USA
| | - Gabriel Acién
- Chemical Engineering Department, University of Almería, Spain
| | - Yolanda Cantón
- Agronomy Department, University of Almería, Spain; Research Centre for Scientific Collections from the University of Almeria (CECOUAL), Spain
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Quantification of extracellular and biomass carbohydrates by Arthrospira under nitrogen starvation at lab-scale. ALGAL RES 2022. [DOI: 10.1016/j.algal.2022.102907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Rueda E, Altamira-Algarra B, García J. Process optimization of the polyhydroxybutyrate production in the cyanobacteria Synechocystis sp. and Synechococcus sp. BIORESOURCE TECHNOLOGY 2022; 356:127330. [PMID: 35589041 DOI: 10.1016/j.biortech.2022.127330] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 05/11/2022] [Accepted: 05/13/2022] [Indexed: 06/15/2023]
Abstract
The effect of four parameters (acetate, NaCl, inorganic carbon and days in darkness) affecting the polyhydroxybutyrate (PHB) production were tested and optimized for Synechococcus sp. and Synechocystis sp. using a Box-Behnken design. The optimal conditions for Synechocystis sp. were found to be 1.2 g L-1 of acetate, 4 gC L-1 of NaHCO3, 18 g L-1 of NaCl and 0 days in darkness. For Synechococcus sp., equal acetate concentration and days in darkness, and lower inorganic carbon and NaCl concentrations than those for Synechocystis sp. were needed (0.05 g L-1 inorganic carbon and 9 g L-1 NaCl). Optimal conditions were scaled up to 3 L photobioreactors. Using Synechocystis sp., 5.6 %dcw of PHB was obtained whether adding or not acetate. In opposition, a maximum of 26.1 %dcw by using acetate was reached with Synechococcus sp. These results provide an easy method to optimize the cultivation conditions to enhance PHB production with cyanobacteria.
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Affiliation(s)
- Estel Rueda
- GEMMA-Group of Environmental Engineering and Microbiology, Department of Civil and Environmental Engineering, Escola d'Enginyeria de Barcelona Est (EEBE), Universitat Politècnica de Catalunya-BarcelonaTech, Av. Eduard Maristany 16, Building C5.1, E-08019 Barcelona, Spain
| | - Beatriz Altamira-Algarra
- GEMMA-Group of Environmental Engineering and Microbiology, Department of Civil and Environmental Engineering, Escola d'Enginyeria de Barcelona Est (EEBE), Universitat Politècnica de Catalunya-BarcelonaTech, Av. Eduard Maristany 16, Building C5.1, E-08019 Barcelona, Spain
| | - Joan García
- GEMMA-Group of Environmental Engineering and Microbiology, Department of Civil and Environmental Engineering, Universitat Politècnica de Catalunya-BarcelonaTech, c/ Jordi Girona 1-3, Building D1, E-08034 Barcelona. Spain.
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Wu W, Du W, Gallego RP, Hellingwerf KJ, van der Woude AD, Branco dos Santos F. Using osmotic stress to stabilize mannitol production in Synechocystis sp. PCC6803. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:117. [PMID: 32636923 PMCID: PMC7331161 DOI: 10.1186/s13068-020-01755-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 06/23/2020] [Indexed: 05/03/2023]
Abstract
BACKGROUND Mannitol is a C(6) polyol that is used in the food and medical sector as a sweetener and antioxidant, respectively. The sustainable production of mannitol, especially via the direct conversion of CO2 by photosynthetic cyanobacteria, has become increasingly appealing. However, previous work aiming to achieve mannitol production in the marine Synechococcus sp. PCC7002 via heterologous expression of mannitol-1-phosphate-5-dehydrogenase (mtlD) and mannitol-1-phosphatase (m1p, in short: a 'mannitol cassette'), proved to be genetically unstable. In this study, we aim to overcome this genetic instability by conceiving a strategy to stabilize mannitol production using Synechocystis sp. PCC6803 as a model cyanobacterium. RESULTS Here, we explore the stabilizing effect that mannitol production may have on cells faced with osmotic stress, in the freshwater cyanobacterium Synechocystis sp. PCC6803. We first validated that mannitol can function as a compatible solute in Synechocystis sp. PCC6803, and in derivative strains in which the ability to produce one or both of the native compatible solutes was impaired. Wild-type Synechocystis, complemented with a mannitol cassette, indeed showed increased salt tolerance, which was even more evident in Synechocystis strains in which the ability to synthesize the endogenous compatible solutes was impaired. Next we tested the genetic stability of all these strains with respect to their mannitol productivity, with and without salt stress, during prolonged turbidostat cultivations. The obtained results show that mannitol production under salt stress conditions in the Synechocystis strain that cannot synthesize its endogenous compatible solutes is remarkably stable, while the control strain completely loses this ability in only 6 days. DNA sequencing results of the control groups that lost the ability to synthesize mannitol revealed that multiple types of mutation occurred in the mtlD gene that can explain the disruption of mannitol production. CONCLUSIONS Mannitol production in freshwater Synechocsytis sp. PCC6803 confers it with increased salt tolerance. Under this strategy, genetically instability which was the major challenge for mannitol production in cyanobacteria is tackled. This paper marks the first report of utilization of the response to salt stress as a factor that can increase the stability of mannitol production in a cyanobacterial cell factory.
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Affiliation(s)
- Wenyang Wu
- Molecular Microbial Physiology Group, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Wei Du
- Molecular Microbial Physiology Group, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Ruth Perez Gallego
- Photanol B.V, Matrix V, Science Park 406, 1098 XH Amsterdam, The Netherlands
- Present Address: NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Microbiology and Biogeochemistry, Utrecht University, P.O. Box 59, Den Burg, Texel, 1790 AB Utrecht, The Netherlands
| | - Klaas J. Hellingwerf
- Molecular Microbial Physiology Group, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
- Photanol B.V, Matrix V, Science Park 406, 1098 XH Amsterdam, The Netherlands
| | | | - Filipe Branco dos Santos
- Molecular Microbial Physiology Group, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
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