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Wang B, Li X, Wang G. Responses of the desert green algae, Chlorella sp. to drought stress. JOURNAL OF PHYCOLOGY 2023; 59:1299-1309. [PMID: 37864776 DOI: 10.1111/jpy.13399] [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: 05/29/2023] [Revised: 07/17/2023] [Accepted: 08/01/2023] [Indexed: 10/23/2023]
Abstract
Desert algae are important components of the desert soil crust and play an essential role in desert soil ecosystem development. Owing to their special habitat, desert algae are often exposed to harsh environments, among which drought represents the most common stress. Green algae are considered to have drought tolerance potential; however, only a few studies have investigated this. In this study, we selected the green alga Chlorella sp., which was isolated from desert soil, and studied its physiological response to polyethylene glycol (PEG) 6000-induced drought stress. The results showed that drought stress can affect the photosynthetic efficiency of Chlorella sp., reduce its water retention ability, and destroy its ultrastructure. However, Chlorella sp. can cope with drought stress through a series of physiological regulatory strategies. Protective strategies include quick recovery of photosynthetic efficiency and increased chlorophyll content. In addition, induced synthesis of soluble proteins, lipids, and extracellular polysaccharide (EPS), and accumulation of osmotic regulatory substances, such as sucrose and trehalose, also contribute to improving drought tolerance in Chlorella sp. This study provides insights into the physiological responses of Chlorella sp. to drought stress, which may be valuable for understanding the underlying drought adaptation mechanisms of desert green algae.
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Affiliation(s)
- Bo Wang
- Jiangxi Key Laboratory of Industrial Ecological Simulation and Environmental Health in Yangtze River Basin, Jiujiang University, Jiujiang, China
- College of Resource & Environment, Jiujiang University, Jiujiang, China
| | - Xiaoyan Li
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Gaohong Wang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
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Fadhil SH, Ismail ZZ. Influence of Light Color on Power Generation and Microalgae Growth in Photosynthetic Microbial Fuel Cell with Chlorella Vulgaris Microalgae as Bio-Cathode. Curr Microbiol 2023; 80:177. [PMID: 37036508 DOI: 10.1007/s00284-023-03292-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 03/28/2023] [Indexed: 04/11/2023]
Abstract
Photosynthetic microbial fuel cell (PMFC) is an environmentally friendly sustainable technique for simultaneous wastewater treatment and power recovery. PMFC utilizes the microalgae to generate oxygen by photosynthesis process in the biocathode. Light sources and intensities have direct effect on chlorophyll pigment formation, photosynthesis processes and microalgae growth. In this study, Chlorella vulgaris was utilized as biocathode in PMFC fed with actual slaughterhouse wastewater. The biocathode was illuminated with florescent light as well as yellow, red and blue LED lights with light intensities of 67.46, 47.03, 26.18 and 4.70 µmol/m.s, respectively. Power output and microalgae growth were considered in evaluating the PMFC performance. Results demonstrated that the highest power output was 217.04 mW/m2 generated under florescent light compared to 28.41, 171.08, and 21.65 mW/m2 observed under yellow, red and blue LEDs, respectively. Additionally, statistical analysis was performed using fifth-degree polynomial model which fitted well the experimental data with a determination coefficient (R2) > 0.97. The results reflected a high confidence level in depicting the growth mechanism of Chlorella vulgaris under lighting sources with different light colors and intensities.
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Affiliation(s)
- Safa H Fadhil
- Department of Environmental Engineering, University of Baghdad, Baghdad, Iraq
| | - Zainab Z Ismail
- Department of Environmental Engineering, University of Baghdad, Baghdad, Iraq.
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Xing Q, Bi G, Cao M, Belcour A, Aite M, Mo Z, Mao Y. Comparative Transcriptome Analysis Provides Insights into Response of Ulva compressa to Fluctuating Salinity Conditions. JOURNAL OF PHYCOLOGY 2021; 57:1295-1308. [PMID: 33715182 DOI: 10.1111/jpy.13167] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/18/2021] [Accepted: 03/01/2021] [Indexed: 06/12/2023]
Abstract
Ulva compressa, a green tide-forming species, can adapt to hypo-salinity conditions, such as estuaries and brackish lakes. To understand the underlying molecular mechanisms of hypo-salinity stress tolerance, transcriptome-wide gene expression profiles in U. compressa were created using digital gene expression profiles. The RNA-seq data were analyzed based on the comparison of differently expressed genes involved in specific pathways under hypo-salinity and recovery conditions. The up-regulation of genes in photosynthesis and glycolysis pathways may contribute to the recovery of photosynthesis and energy metabolism, which could provide sufficient energy for the tolerance under long-term hyposaline stress. Multiple strategies, such as ion transportation and osmolytes metabolism, were performed to maintain the osmotic homeostasis. Additionally, several long noncoding RNA were differently expressed during the stress, which could play important roles in the osmotolerance. Our work will serve as an essential foundation for the understanding of the tolerance mechanism of U. compressa under the fluctuating salinity conditions.
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Affiliation(s)
- Qikun Xing
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
- Integrative Biology of Marine Models (LBI2M, UMR8227), Station Biologique deRoscoff (SBR), CNRS, Sorbonne Université, 29680, Roscoff, France
| | - Guiqi Bi
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
- Agricultural Synthetic Biology Center, Chinese Academy of Agricultural Sciences, Agricultural Genomes Institute at Shenzhen, Shenzhen, 518120, China
| | - Min Cao
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Arnaud Belcour
- Inria, CNRS, IRISA, Equipe Dyliss, Univ Rennes, Rennes, France
| | - Méziane Aite
- Inria, CNRS, IRISA, Equipe Dyliss, Univ Rennes, Rennes, France
| | - Zhaolan Mo
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Yunxiang Mao
- MOE Key Laboratory of Utilization and Conservation for Tropical Marine Bioresources, College of Fisheries and Life Science, Hainan Tropical Ocean University, Sanya, 572022, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
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de Alvarenga LV, Lucius S, Vaz MGMV, Araújo WL, Hagemann M. The novel strain Desmonostoc salinum CCM-UFV059 shows higher salt and desiccation resistance compared to the model strain Nostoc sp. PCC7120. JOURNAL OF PHYCOLOGY 2020; 56:496-506. [PMID: 31925964 DOI: 10.1111/jpy.12968] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 12/04/2019] [Indexed: 06/10/2023]
Abstract
Desmonostoc salinum CCM-UFV059 (Desmonostoc) is a novel cyanobacterial strain of the order Nostocales isolated from a saline-alkaline lake. The acclimation towards salt and desiccation stress of Desmonostoc was compared to the related and well-characterized model strain Nostoc sp. PCC7120 (Nostoc). Salt-stressed cells of Desmonostoc maintained low cellular Na+ concentrations and accumulated high amounts of compatible solutes, mainly sucrose and to a lower extent trehalose. These features permitted Desmonostoc to grow and maintain photosynthesis at 2-fold higher salinities than Nostoc. Moreover, Desmonostoc also induced sucrose over-accumulation under desiccation, which allowed this strain to recover from this stress in contrast to Nostoc. Additional mechanisms such as the presence of highly unsaturated lipids in the membrane and an efficient ion transport system could also explain, at least partially, how Desmonostoc is able to acclimate to high salinities and to resist longer desiccation periods. Collectively, our results provide first insights into the physiological and metabolic adaptations explaining the remarkable high salt and desiccation tolerance, which qualify Desmonostoc as an attractive model for further analysis of stress acclimation among heterocystous N2 -fixing cyanobacteria.
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Affiliation(s)
- Luna Viggiano de Alvarenga
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
- Max-Planck Partner Group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
- Institut für Biowissenschaften, Abteilung Pflanzenphysiologie, Universität Rostock, A.-Einstein-Str. 3, Rostock, D-18059, Germany
| | - Stefan Lucius
- Institut für Biowissenschaften, Abteilung Pflanzenphysiologie, Universität Rostock, A.-Einstein-Str. 3, Rostock, D-18059, Germany
| | - Marcelo Gomes Marçal Vieira Vaz
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
- Max-Planck Partner Group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
| | - Wagner L Araújo
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
- Max-Planck Partner Group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
| | - Martin Hagemann
- Institut für Biowissenschaften, Abteilung Pflanzenphysiologie, Universität Rostock, A.-Einstein-Str. 3, Rostock, D-18059, Germany
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Physiological and Metabolic Responses of Freshwater and Brackish-Water Strains of Microcystis aeruginosa Acclimated to a Salinity Gradient: Insight into Salt Tolerance. Appl Environ Microbiol 2019; 85:AEM.01614-19. [PMID: 31444201 DOI: 10.1128/aem.01614-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 08/18/2019] [Indexed: 12/24/2022] Open
Abstract
Proliferation of microcystin (MC)-producing Microcystis aeruginosa in brackish waters has been described in several locations and represents a new concern for public and environmental health. While the impact of a sudden salinity increase on M. aeruginosa physiology has been studied, less is known about the mechanisms involved in salt tolerance after acclimation. This study aims to compare the physiological responses of two strains of M. aeruginosa (PCC 7820 and PCC 7806), which were isolated from contrasted environments, to increasing salinities. After acclimation, growth and MC production rates were determined and metabolomic analyses were conducted. For both strains, salinity decreased the biovolume, growth, and MC production rates and induced the accumulation of polyunsaturated lipids identified as monogalactosyldiacylglycerol. The distinct salt tolerances (7.5 and 16.9) obtained between the freshwater (PCC 7820) and the brackish-water (PCC 7806) strains suggested different strategies to cope with the osmotic pressure, as revealed by targeted and untargeted metabolomic analyses. An accumulation of trehalose as the main compatible solute was obtained in the freshwater strain, while sucrose was mainly accumulated in the brackish one. Moreover, distinct levels of glycine betaine and proline accumulation were noted. Altogether, metabolomic analysis illustrated a strain-specific response to salt tolerance, involving compatible solute production.IMPORTANCE Blooms of Microcystis aeruginosa and the production of microcystins are major issues in eutrophic freshwater bodies. Recently, an increasing number of proliferations of M. aeruginosa in brackish water has been documented. The occurrence of both M. aeruginosa and microcystins in coastal areas represents a new threat for human and environmental health. In order to better describe the mechanisms involved in Microcystis sp. proliferation in brackish water, this study used two M. aeruginosa strains isolated from fresh and brackish waters. High salinity reduced the growth rate and microcystin production rate of M. aeruginosa In order to cope with higher salinities, the strains accumulated different cyanobacterial compatible solutes, as well as unsaturated lipids, explaining their distinct salt tolerance.
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Panahi Y, Yari Khosroushahi A, Sahebkar A, Heidari HR. Impact of Cultivation Condition and Media Content on Chlorella vulgaris Composition. Adv Pharm Bull 2019; 9:182-194. [PMID: 31380244 PMCID: PMC6664117 DOI: 10.15171/apb.2019.022] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 04/17/2019] [Accepted: 05/04/2019] [Indexed: 11/09/2022] Open
Abstract
Microalgae are a source material in food, pharmacy, and cosmetics industries for producing various products including high-protein nutritional supplements, synthetic pharmaceuticals, and natural colors. A promising algal source for such productions is Chlorella vulgaris which contains a considerable protein content. Similar to other microalgae, its desirability is minimal nutrient requirements since they are unicellular, photosynthetic, and fast-growing microorganisms. Another propitious option to be produced by C. vulgaris is biodiesel, since it is rich in oil too. Besides, algal well thriving in presence of increased amount of carbon dioxide makes them a practicable alternative biofuel resource without some problems of the traditional ones. At the same time, C. vulgaris is also a promising source for nutraceuticals such as amino acids, vitamins, and antioxidants. This review aims to discuss the conditions need to be observed for achieving a favorable growth efficiency of the C. vulgaris, as well as targeted productions such as biomass, antioxidant, and biofuel. Additionally, different approaches to induce any specific production are also considered comprehensively.
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Affiliation(s)
- Yunes Panahi
- Chemical Injuries Research Center, Systems Biology and Poisoning Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Ahmad Yari Khosroushahi
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
- Department of Medical Nanotechnology, Faculty of Advanced Medical Science, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Amirhossein Sahebkar
- Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hamid Reza Heidari
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
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Gustavs L, Schumann R, Karsten U, Lorenz M. Mixotrophy in the terrestrial green alga Apatococcus lobatus (Trebouxiophyceae, Chlorophyta). JOURNAL OF PHYCOLOGY 2016; 52:311-314. [PMID: 27037595 DOI: 10.1111/jpy.12381] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 12/25/2015] [Indexed: 06/05/2023]
Abstract
The green microalga Apatococcus lobatus is widely distributed in terrestrial habitats throughout many climatic zones. It dominates green biofilms on natural and artificial substrata in temperate latitudes and is regarded as a key genus of obligate terrestrial consortia. Until now, its isolation, cultivation and application as a terrestrial model organism has been hampered by slow growth rates and low growth capacities. A mixotrophic culturing approach clearly enhanced the accumulation of biomass, thereby permitting the future application of A. lobatus in different types of bio-assays necessary for material and biofilm research. The ability of A. lobatus to grow mixotrophically is assumed as a competitive advantage in terrestrial habitats.
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Affiliation(s)
- Lydia Gustavs
- Institute of Biological Sciences, Applied Ecology and Phycology, University of Rostock, Albert-Einstein-Strasse 3, Rostock, 18051, Germany
| | - Rhena Schumann
- Institute of Biological Sciences, Applied Ecology and Phycology, University of Rostock, Albert-Einstein-Strasse 3, Rostock, 18051, Germany
| | - Ulf Karsten
- Institute of Biological Sciences, Applied Ecology and Phycology, University of Rostock, Albert-Einstein-Strasse 3, Rostock, 18051, Germany
| | - Maike Lorenz
- Albrecht-von-Haller-Institute for Plant Sciences, Experimental Phycology and Culture Collection of Algae (SAG), Georg-August-University Göttingen, Nikolausberger Weg 18, Göttingen, 37073, Germany
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Crits-Christoph A, Robinson CK, Ma B, Ravel J, Wierzchos J, Ascaso C, Artieda O, Souza-Egipsy V, Casero MC, DiRuggiero J. Phylogenetic and Functional Substrate Specificity for Endolithic Microbial Communities in Hyper-Arid Environments. Front Microbiol 2016; 7:301. [PMID: 27014224 PMCID: PMC4784552 DOI: 10.3389/fmicb.2016.00301] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 02/23/2016] [Indexed: 11/13/2022] Open
Abstract
Under extreme water deficit, endolithic (inside rock) microbial ecosystems are considered environmental refuges for life in cold and hot deserts, yet their diversity and functional adaptations remain vastly unexplored. The metagenomic analyses of the communities from two rock substrates, calcite and ignimbrite, revealed that they were dominated by Cyanobacteria, Actinobacteria, and Chloroflexi. The relative distribution of major phyla was significantly different between the two substrates and biodiversity estimates, from 16S rRNA gene sequences and from the metagenomic data, all pointed to a higher taxonomic diversity in the calcite community. While both endolithic communities showed adaptations to extreme aridity and to the rock habitat, their functional capabilities revealed significant differences. ABC transporters and pathways for osmoregulation were more diverse in the calcite chasmoendolithic community. In contrast, the ignimbrite cryptoendolithic community was enriched in pathways for secondary metabolites, such as non-ribosomal peptides (NRP) and polyketides (PK). Assemblies of the metagenome data produced population genomes for the major phyla found in both communities and revealed a greater diversity of Cyanobacteria population genomes for the calcite substrate. Draft genomes of the dominant Cyanobacteria in each community were constructed with more than 93% estimated completeness. The two annotated proteomes shared 64% amino acid identity and a significantly higher number of genes involved in iron update, and NRPS gene clusters, were found in the draft genomes from the ignimbrite. Both the community-wide and genome-specific differences may be related to higher water availability and the colonization of large fissures and cracks in the calcite in contrast to a harsh competition for colonization space and nutrient resources in the narrow pores of the ignimbrite. Together, these results indicated that the habitable architecture of both lithic substrates- chasmoendolithic versus cryptoendolithic - might be an essential element in determining the colonization and the diversity of the microbial communities in endolithic substrates at the dry limit for life.
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Affiliation(s)
| | | | - Bing Ma
- Institute for Genome Sciences, University of Maryland School of Medicine Baltimore, MD, USA
| | - Jacques Ravel
- Institute for Genome Sciences, University of Maryland School of Medicine Baltimore, MD, USA
| | - Jacek Wierzchos
- Department of Biochemistry and Microbial Ecology, Museo Nacional de Ciencias Naturales - Consejo Superior de Investigaciones Científicas Madrid, Spain
| | - Carmen Ascaso
- Department of Biochemistry and Microbial Ecology, Museo Nacional de Ciencias Naturales - Consejo Superior de Investigaciones Científicas Madrid, Spain
| | | | - Virginia Souza-Egipsy
- Instituto de Ciencias Agrarias - Consejo Superior de Investigaciones Científicas Madrid, Spain
| | - M Cristina Casero
- Department of Biochemistry and Microbial Ecology, Museo Nacional de Ciencias Naturales - Consejo Superior de Investigaciones Científicas Madrid, Spain
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Holzinger A, Pichrtová M. Abiotic Stress Tolerance of Charophyte Green Algae: New Challenges for Omics Techniques. FRONTIERS IN PLANT SCIENCE 2016; 7:678. [PMID: 27242877 PMCID: PMC4873514 DOI: 10.3389/fpls.2016.00678] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 05/02/2016] [Indexed: 05/20/2023]
Abstract
Charophyte green algae are a paraphyletic group of freshwater and terrestrial green algae, comprising the classes of Chlorokybophyceae, Coleochaetophyceae, Klebsormidiophyceae, Zygnematophyceae, Mesostigmatophyceae, and Charo- phyceae. Zygnematophyceae (Conjugating green algae) are considered to be closest algal relatives to land plants (Embryophyta). Therefore, they are ideal model organisms for studying stress tolerance mechanisms connected with transition to land, one of the most important events in plant evolution and the Earth's history. In Zygnematophyceae, but also in Coleochaetophyceae, Chlorokybophyceae, and Klebsormidiophyceae terrestrial members are found which are frequently exposed to naturally occurring abiotic stress scenarios like desiccation, freezing and high photosynthetic active (PAR) as well as ultraviolet (UV) irradiation. Here, we summarize current knowledge about various stress tolerance mechanisms including insight provided by pioneer transcriptomic and proteomic studies. While formation of dormant spores is a typical strategy of freshwater classes, true terrestrial groups are stress tolerant in vegetative state. Aggregation of cells, flexible cell walls, mucilage production and accumulation of osmotically active compounds are the most common desiccation tolerance strategies. In addition, high photophysiological plasticity and accumulation of UV-screening compounds are important protective mechanisms in conditions with high irradiation. Now a shift from classical chemical analysis to next-generation genome sequencing, gene reconstruction and annotation, genome-scale molecular analysis using omics technologies followed by computer-assisted analysis will give new insights in a systems biology approach. For example, changes in transcriptome and role of phytohormone signaling in Klebsormidium during desiccation were recently described. Application of these modern approaches will deeply enhance our understanding of stress reactions in an unbiased non-targeted view in an evolutionary context.
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Affiliation(s)
- Andreas Holzinger
- Unit of Functional Plant Biology, Institute of Botany, University of Innsbruck, InnsbruckAustria
- *Correspondence: Andreas Holzinger,
| | - Martina Pichrtová
- Unit of Functional Plant Biology, Institute of Botany, University of Innsbruck, InnsbruckAustria
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Pichrtová M, Hájek T, Elster J. Osmotic stress and recovery in field populations of Zygnema sp. (Zygnematophyceae, Streptophyta) on Svalbard (High Arctic) subjected to natural desiccation. FEMS Microbiol Ecol 2014; 89:270-80. [PMID: 24476153 DOI: 10.1111/1574-6941.12288] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 01/06/2014] [Accepted: 01/16/2014] [Indexed: 12/01/2022] Open
Abstract
Zygnema is a genus of filamentous green algae belonging to the class of Zygnematophyceae (Streptophyta). In the Arctic, it typically forms extensive mats in habitats that regularly dry out during summer, and therefore, mechanisms of stress resistance are expected. We investigated its natural populations with respect to production of specialized desiccation-resistant cells and osmotic acclimation. Six populations in various stages of natural desiccation were selected, from wet biomass floating in water to dried paper-like crusts. After rewetting, plasmolysis and osmotic stress effects were studied using hypertonic sorbitol solutions, and the physiological state was estimated using chlorophyll a fluorescence parameters. All populations of Zygnema sp. formed stationary-phase cells filled with storage products. In green algal research, such cells are traditionally called akinetes. However, the populations differed in their reaction to osmotic stress. Whereas the wet-collected samples were strongly impaired, the osmotic stress resistance of the naturally dried samples was comparable to that of true aeroterrestrial algae. We showed that arctic populations of Zygnema acclimate well to natural desiccation via hardening that is mediated by slow desiccation. As no other types of specialized cells were observed, we assume that the naturally hardened akinetes also play a key role in winter survival.
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Affiliation(s)
- Martina Pichrtová
- Institute of Botany, Academy of Sciences of the Czech Republic, Třeboň, Czech Republic; Department of Botany, Faculty of Science, Charles University in Prague, Prague, Czech Republic
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Bremauntz P, Fernández-Linares LC, Cañizares-Villanueva RO. Osmotic Stress Effect over Carbohydrate Production in a Native Starin of <i>Scenedesmus</i> sp. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/nr.2014.51002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Manna S, Chaudhuri K, Bhattacharyya S, Bhattacharyya M. Dynamics of Sundarban estuarine ecosystem: eutrophication induced threat to mangroves. SALINE SYSTEMS 2010; 6:8. [PMID: 20699005 PMCID: PMC2928246 DOI: 10.1186/1746-1448-6-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Accepted: 08/11/2010] [Indexed: 12/03/2022]
Abstract
Background Sundarbans is the largest chunk of mangrove forest and only tiger mangrove land in the world. Compared to the rich species diversity and uniqueness, very few studies have so far been conducted here, mainly due to its inaccessibility. This study explores water quality, density of biomass, species diversity, phytoplankton abundance and bacterial population of a tidal creek in Sunderban estuary during the post and pre monsoon period of 2008-09. Results Phytoplankton community was observed to be dominated by diatoms (Biacillariophyceae) followed by Pyrrophyceae (Dinoflagellates) and Chlorophyceae. A total of 46 taxa belonging to 6 groups were recorded. Other algal groups were Cyanophyceae, Euglenophyceae and Chrysophyceae. Species diversity was highest in summer (March) and lowest in winter season (November) in all the sample stations indicating its close correlation with ambient temperature. Species evenness was fairly high in all five stations throughout the study period. Present study indicated that dissolved oxygen, nutrients and turbidity are the limiting factors for the phytoplankton biomass. The estuary was in eutrophic condition (Chlorophyll-a ≥10 μg/L) in winter. During the month of May phytoplankton biomass declined and at high salinity level (21.2PSU) new phytoplankton species take over, which are definitely better resilient to the high saline environment. Bio-indicator species like Polykrikos schwartzil, Dinophysis norvegica and Prorocentrum concavum points to moderately polluted water quality of the estuary. Conclusion Eutrophication as well as presence of toxic Dinoflagellates and Cyanophyceae in the tidal creek of Sundarban estuary definitely revealed the deteriorated status of the water quality. The structure and function of the mangrove food web is unique, driven by both marine and terrestrial components. But little attention has been paid so far to the adaptive responses of mangrove biota to the various disturbances, and now our work unfolds the fact that marine status of Sundarban estuary is highly threatened which in turn will affect the ecology of the mangrove. This study indicates that ecosystem dynamics of the world heritage site Sundarban may facilitate bioinvasion putting a question mark on the sustainability of mangroves.
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Affiliation(s)
- Suman Manna
- Institute of Environmental Studies and Wetland Management, DD-24, Sector-I, Salt lake, Kolkata-700064, India
| | - Kaberi Chaudhuri
- Institute of Environmental Studies and Wetland Management, DD-24, Sector-I, Salt lake, Kolkata-700064, India
| | - Somenath Bhattacharyya
- Institute of Environmental Studies and Wetland Management, DD-24, Sector-I, Salt lake, Kolkata-700064, India
| | - Maitree Bhattacharyya
- Department of Biochemistry, University of Calcutta, 35, B.C. Road, kolkata-700019, India
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Klähn S, Steglich C, Hess WR, Hagemann M. Glucosylglycerate: a secondary compatible solute common to marine cyanobacteria from nitrogen-poor environments. Environ Microbiol 2010; 12:83-94. [DOI: 10.1111/j.1462-2920.2009.02045.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Aeroterrestrial Algae Growing on Man-Made Surfaces. CELLULAR ORIGIN, LIFE IN EXTREME HABITATS AND ASTROBIOLOGY 2007. [DOI: 10.1007/978-1-4020-6112-7_32] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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