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Wang R, Yan SJ, Liu C, Guo H, Cui YN. Comparative Physiological and Gene Expression Analyses Reveal Mechanisms Involved in Maintaining Photosynthesis Capacity, Alleviating Ion Toxicity and Oxidative Stress of Kentucky Bluegrass under NaCl Treatment. PLANTS (BASEL, SWITZERLAND) 2024; 13:2107. [PMID: 39124225 PMCID: PMC11313982 DOI: 10.3390/plants13152107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2024] [Revised: 07/24/2024] [Accepted: 07/25/2024] [Indexed: 08/12/2024]
Abstract
Kentucky bluegrass (Poa pratensis L.), a widely used cool-season turfgrass, shows a high sensitivity to soil salinity. Clarifying the adaptative mechanisms of Kentucky bluegrass that serve to improve its salt tolerance in saline environments is urgent for the application of this turfgrass in salt-affected regions. In this study, physiological responses of the Kentucky bluegrass cultivars "Explorer" and "Blue Best" to NaCl treatment, as well as gene expressions related to photosynthesis, ion transport, and ROS degradation, were analyzed. The results showed that the growth of "Explorer" was obviously better compared to "Blue Best" under 400 mM NaCl treatment. "Explorer" exhibited a much stronger photosynthetic capacity than "Blue Best" under NaCl treatment, and the expression of key genes involved in chlorophyll biosynthesis, photosystem II, and the Calvin cycle in "Explorer" was greatly induced by salt treatment. Compared with "Blue Best", "Explorer" could effectively maintain Na+/K+ homeostasis in its leaves under NaCl treatment, which can be attributed to upregulated expression of genes, such as HKT1;5, HAK5, and SKOR. The relative membrane permeability and contents of O2- and H2O2 in "Explorer" were significantly lower than those in "Blue Best" under NaCl treatment, and, correspondingly, the activities of SOD and POD in the former were significantly higher than in the latter. Moreover, the expression of genes involved in the biosynthesis of enzymes in the ROS-scavenging system of "Explorer" was immediately upregulated after NaCl treatment. Additionally, free proline and betaine are important organic osmolytes for maintaining hydration status in Kentucky bluegrass under NaCl treatment, as the contents of these metabolites in "Explorer" were significantly higher than in "Blue Best". This work lays a theoretical basis for the improvement of salt tolerance in Kentucky bluegrass.
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Affiliation(s)
| | | | | | - Huan Guo
- College of Grassland Agriculture, Northwest A&F University, Yangling 712100, China; (R.W.); (S.-J.Y.); (C.L.)
| | - Yan-Nong Cui
- College of Grassland Agriculture, Northwest A&F University, Yangling 712100, China; (R.W.); (S.-J.Y.); (C.L.)
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2
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Keil L, Qoura FM, Breitsameter JM, Rieger B, Garbe D, Brück TB. Evaluation of Chemical and Physical Triggers for Enhanced Photosynthetic Glycerol Production in Different Dunaliella Isolates. Microorganisms 2024; 12:1318. [PMID: 39065087 PMCID: PMC11278730 DOI: 10.3390/microorganisms12071318] [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: 05/23/2024] [Revised: 06/21/2024] [Accepted: 06/24/2024] [Indexed: 07/28/2024] Open
Abstract
The salt-tolerant marine microalgae Dunaliella tertiolecta is reported to generate significant amounts of intracellular glycerol as an osmoprotectant under high salt conditions. This study highlights the phylogenetic distribution and comparative glycerol biosynthesis of seven new Dunaliella isolates compared to a D. tertiolecta reference strain. Phylogenetic analysis indicates that all Dunaliella isolates are newly discovered and do not relate to the D. tertiolecta reference. Several studies have identified light color and intensity and salt concentration alone as the most inducing factors impacting glycerol productivity. This study aims to optimize glycerol production by investigating these described factors singularly and in combination to improve the glycerol product titer. Glycerol production data indicate that cultivation with white light of an intensity between 500 and 2000 μmol m-2 s-1 as opposed to 100 μmol m-2 s-1 achieves higher biomass and thereby higher glycerol titers for all our tested Dunaliella strains. Moreover, applying higher light intensity in a cultivation of 1.5 M NaCl and an increase to 3 M NaCl resulted in hyperosmotic stress conditions, providing the highest glycerol titer. Under these optimal light intensity and salt conditions, the glycerol titer of D. tertiolecta could be doubled to 0.79 mg mL-1 in comparison to 100 μmol m-2 s-1 and salt stress to 2 M NaCl, and was higher compared to singularly optimized conditions. Furthermore, under the same conditions, glycerol extracts from new Dunaliella isolates did provide up to 0.94 mg mL-1. This highly pure algae-glycerol obtained under optimal production conditions can find widespread applications, e.g., in the pharmaceutical industry or the production of sustainable carbon fibers.
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Affiliation(s)
- Linda Keil
- Werner Siemens Laboratory of Synthetic Biotechnology, TUM-School of Natural Sciences, Technical University of Munich (TUM), 85748 Garching, Germany;
| | - Farah Mitry Qoura
- Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Nobelstraße 12, 70569 Stuttgart, Germany;
| | - Jonas Martin Breitsameter
- Wacker-Laboratory of Macromolecular Chemistry, TUM-School of Natural Sciences, Technical University of Munich (TUM), 85748 Garching, Germany; (J.M.B.); (B.R.)
| | - Bernhard Rieger
- Wacker-Laboratory of Macromolecular Chemistry, TUM-School of Natural Sciences, Technical University of Munich (TUM), 85748 Garching, Germany; (J.M.B.); (B.R.)
| | - Daniel Garbe
- Werner Siemens Laboratory of Synthetic Biotechnology, TUM-School of Natural Sciences, Technical University of Munich (TUM), 85748 Garching, Germany;
| | - Thomas Bartholomäus Brück
- Werner Siemens Laboratory of Synthetic Biotechnology, TUM-School of Natural Sciences, Technical University of Munich (TUM), 85748 Garching, Germany;
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3
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Wei H, Wang X, Wang K, Tang X, Zhang N, Si H. Transcription factors as molecular switches regulating plant responses to drought stress. PHYSIOLOGIA PLANTARUM 2024; 176:e14366. [PMID: 38812034 DOI: 10.1111/ppl.14366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Revised: 05/13/2024] [Accepted: 05/14/2024] [Indexed: 05/31/2024]
Abstract
Plants often experience abiotic stress, which severely affects their growth. With the advent of global warming, drought stress has become a pivotal factor affecting crop yield and quality. Increasing numbers of studies have focused on elucidating the molecular mechanisms underlying plant responses to drought stress. As molecular switches, transcription factors (TFs) are key participants in drought-resistance regulatory networks in crops. TFs regulate the transcription of downstream genes and are regulated by various upstream regulatory factors. Therefore, understanding the mechanisms of action of TFs in regulating drought stress can help enhance the adaptive capacity of crops under drought conditions. In this review, we summarize the structural characteristics of several common TFs, their multiple drought-response pathways, and recently employed research strategies. We describe the application of new technologies such as analysis of stress granule dynamics and function, multi-omics data, gene editing, and molecular crosstalk between TFs in drought resistance. This review aims to familiarize readers with the regulatory network of TFs in drought resistance and to provide a reference for examining the molecular mechanisms of drought resistance in plants and improving agronomic traits.
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Affiliation(s)
- Han Wei
- State Key Laboratory of Aridland Crop Science, Gansu Agricultural University, Lanzhou, People's Republic of China
- College of Agronomy, Gansu Agricultural University, Lanzhou, People's Republic of China
| | - Xiao Wang
- State Key Laboratory of Aridland Crop Science, Gansu Agricultural University, Lanzhou, People's Republic of China
- College of Agronomy, Gansu Agricultural University, Lanzhou, People's Republic of China
| | - Kaitong Wang
- State Key Laboratory of Aridland Crop Science, Gansu Agricultural University, Lanzhou, People's Republic of China
- College of Agronomy, Gansu Agricultural University, Lanzhou, People's Republic of China
| | - Xun Tang
- State Key Laboratory of Aridland Crop Science, Gansu Agricultural University, Lanzhou, People's Republic of China
- College of Life Science and Technology, Gansu Agricultural University, Lanzhou, People's Republic of China
| | - Ning Zhang
- State Key Laboratory of Aridland Crop Science, Gansu Agricultural University, Lanzhou, People's Republic of China
- College of Life Science and Technology, Gansu Agricultural University, Lanzhou, People's Republic of China
| | - Huaijun Si
- State Key Laboratory of Aridland Crop Science, Gansu Agricultural University, Lanzhou, People's Republic of China
- College of Life Science and Technology, Gansu Agricultural University, Lanzhou, People's Republic of China
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Tekin N, Ertuğrul Karatay S, Dönmez G. Third generation biobutanol production by Clostridium beijerinckii in a medium containing mixotrophically cultivated Dunaliella salina biomass. Prep Biochem Biotechnol 2024; 54:483-493. [PMID: 37610720 DOI: 10.1080/10826068.2023.2248298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
This study aims the third generation biobutanol production in P2 medium supplemented D. salina biomass mixotrophically cultivated with marble waste (MW). The wastes derived from the marble industry contain approximately 90% of carbon-rich compounds. Microalgal growth in mixotrophic conditions was optimized in the 0.4-2 g/L of MW concentration range. The highest microalgal concentration was obtained as 0.481 g/L in the presence of 1 g/L MW. Furthermore, some important parameters for the production of biobutanol, such as microalgal cultivation conditions, initial mixotrophic microalgal biomass loading (50-300 g/L), and fermentation time (24-96 h) were optimized. The highest biobutanol, total ABE, biobutanol yield and productivity were determined as 11.88 g/L, 13.89 g/L, 0.331 g/g and 0.165 g/L/h at the end of 72 h in P2 medium including 60 g/L glucose and 200 g/L microalgal biomass cultivated in 1 g/L MW, respectively. The results show that D. salina is a suitable raw material for supporting Clostridium beijerinckii DSMZ 6422 cells on biobutanol production. To the best of our knowledge, this is the first study on the use of MW which is a promising feedstock on the mixotrophic cultivation of D. salina for biobutanol production.
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Affiliation(s)
- Nazlıhan Tekin
- Science Faculty, Biology Department, Ankara University, Beşevler, Turkey
| | | | - Gönül Dönmez
- Science Faculty, Biology Department, Ankara University, Beşevler, Turkey
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5
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Chen HH, Pang XH, Wang QH, Chen RQ, Dai JL, Jiang JG. Choline Dehydrogenase Contributes to Salt Tolerance in Dunaliella through Betaine Synthesis. PHYSIOLOGIA PLANTARUM 2024; 176:e14296. [PMID: 38650503 DOI: 10.1111/ppl.14296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 03/25/2024] [Accepted: 03/28/2024] [Indexed: 04/25/2024]
Abstract
In Dunaliella tertiolecta, a microalga renowned for its extraordinary tolerance to high salinity levels up to 4.5 M NaCl, the mechanisms underlying its stress response have largely remained a mystery. In a groundbreaking discovery, this study identifies a choline dehydrogenase enzyme, termed DtCHDH, capable of converting choline to betaine aldehyde. Remarkably, this is the first identification of such an enzyme not just in D. tertiolecta but across the entire Chlorophyta. A 3D model of DtCHDH was constructed, and molecular docking with choline was performed, revealing a potential binding site for the substrate. The enzyme was heterologously expressed in E. coli Rosetta (DE3) and subsequently purified, achieving enzyme activity of 672.2 U/mg. To elucidate the role of DtCHDH in the salt tolerance of D. tertiolecta, RNAi was employed to knock down DtCHDH gene expression. The results indicated that the Ri-12 strain exhibited compromised growth under both high and low salt conditions, along with consistent levels of DtCHDH gene expression and betaine content. Additionally, fatty acid analysis indicated that DtCHDH might also be a FAPs enzyme, catalyzing reactions with decarboxylase activity. This study not only illuminates the role of choline metabolism in D. tertiolecta's adaptation to high salinity but also identifies a novel target for enhancing the NaCl tolerance of microalgae in biotechnological applications.
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Affiliation(s)
- Hao-Hong Chen
- College of Food Science and Bioengineering, South China University of Technology, Guangzhou, China
- Department of Bioengineering, Imperial College London, London, UK
| | - Xiao-Hui Pang
- College of Food Science and Bioengineering, South China University of Technology, Guangzhou, China
| | - Qian-Hui Wang
- College of Food Science and Bioengineering, South China University of Technology, Guangzhou, China
| | - Rui-Qi Chen
- Department of Bioengineering, Imperial College London, London, UK
| | - Ju-Liang Dai
- College of Food Science and Bioengineering, South China University of Technology, Guangzhou, China
| | - Jian-Guo Jiang
- College of Food Science and Bioengineering, South China University of Technology, Guangzhou, China
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Mohanta A, Prasad N, Khadim SR, Singh P, Singh S, Singh A, Kayastha AM, Asthana RK. Optimizing light regimes for neutral lipid accumulation in Dunaliella salina MCC 43: a study on physiological status and carbon allocation. World J Microbiol Biotechnol 2024; 40:82. [PMID: 38285311 DOI: 10.1007/s11274-024-03893-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 01/10/2024] [Indexed: 01/30/2024]
Abstract
Dunaliella salina is a favourable source of high lipid feedstock for biofuel and medicinal chemicals. Low biomass output from microalgae is a significant barrier to industrial-scale commercialisation. The current study aimed to determine how photosynthetic efficiency, carbon fixation, macromolecular synthesis, accumulation of neutral lipids, and antioxidative defence (ROS scavenging enzyme activities) of D. salina cells were affected by different light intensities (LI) (50, 100, 200, and 400 µmol m-2 s-1). The cells when exposed to strong light (400 µmol m-2 s-1) led to reduction in chlorophyll a but the carotenoid content increased by 19% in comparison to the control (LI 100). The amount of carbohydrate changed significantly under high light and in spite of stress inflicted on the cells by high irradiation, a considerable increase in activity of carbonic anhydrase and fixation rate of CO2 were recorded, thus, preserving the biomass content. The high light exposed biomass when subjected to nitrogen-deficient medium led to increase in lipid content (59.92% of the dry cell weight). However, neutral lipid made up 78.26% of the total lipid while other lipids like phospholipid and glycolipid content decreased, showing that the lipid was redistributed in these cells under nitrogen deprivation, making the organism more appropriate for biodiesel/jet fuel use. Although D. salina cells had a relatively longer generation time (3.5 d) than other microalgal cells, an economic analysis concluded that the amount of carotenoid they produced and the quality of their lipids made them more suited for commercialization.
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Affiliation(s)
- Abhishek Mohanta
- R. N. Singh Memorial Laboratory, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, 221005, India
| | - Nitesh Prasad
- R. N. Singh Memorial Laboratory, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, 221005, India
| | - Sk Riyazat Khadim
- P.G. Department of Botany, Dhenkanal Autonomous College, Dhenkanal, Odisha, India
| | - Prabhakar Singh
- Biochemistry Department, North-Eastern Hill University, Shillong, Meghalaya, 793022, India
| | - Savita Singh
- R. N. Singh Memorial Laboratory, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, 221005, India
| | - Avinash Singh
- R. N. Singh Memorial Laboratory, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, 221005, India
| | - A M Kayastha
- School of Biotechnology, Banaras Hindu University, Varanasi, 221005, India
| | - R K Asthana
- R. N. Singh Memorial Laboratory, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, 221005, India.
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7
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Keil L, Mehlmer N, Cavelius P, Garbe D, Haack M, Ritz M, Awad D, Brück T. The Time-Resolved Salt Stress Response of Dunaliella tertiolecta-A Comprehensive System Biology Perspective. Int J Mol Sci 2023; 24:15374. [PMID: 37895054 PMCID: PMC10607294 DOI: 10.3390/ijms242015374] [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: 09/20/2023] [Revised: 10/12/2023] [Accepted: 10/17/2023] [Indexed: 10/29/2023] Open
Abstract
Algae-driven processes, such as direct CO2 fixation into glycerol, provide new routes for sustainable chemical production in synergy with greenhouse gas mitigation. The marine microalgae Dunaliella tertiolecta is reported to accumulate high amounts of intracellular glycerol upon exposure to high salt concentrations. We have conducted a comprehensive, time-resolved systems biology study to decipher the metabolic response of D. tertiolecta up to 24 h under continuous light conditions. Initially, due to a lack of reference sequences required for MS/MS-based protein identification, a high-quality draft genome of D. tertiolecta was generated. Subsequently, a database was designed by combining the genome with transcriptome data obtained before and after salt stress. This database allowed for detection of differentially expressed proteins and identification of phosphorylated proteins, which are involved in the short- and long-term adaptation to salt stress, respectively. Specifically, in the rapid salt adaptation response, proteins linked to the Ca2+ signaling pathway and ion channel proteins were significantly increased. While phosphorylation is key in maintaining ion homeostasis during the rapid adaptation to salt stress, phosphofructokinase is required for long-term adaption. Lacking β-carotene, synthesis under salt stress conditions might be substituted by the redox-sensitive protein CP12. Furthermore, salt stress induces upregulation of Calvin-Benson cycle-related proteins.
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Affiliation(s)
| | | | | | | | | | | | | | - Thomas Brück
- Werner Siemens Chair of Synthetic Biotechnology, Department of Chemistry, Technical University of Munich (TUM), 85748 Garching, Germany; (L.K.); (N.M.); (P.C.); (D.G.); (M.H.); (M.R.); (D.A.)
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8
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Chen HH, Liang MH, Ye ZW, Zhu YH, Jiang JG. Engineering the β-Carotene Metabolic Pathway of Microalgae Dunaliella To Confirm Its Carotenoid Synthesis Pattern in Comparison To Bacteria and Plants. Microbiol Spectr 2023; 11:e0436122. [PMID: 36719233 PMCID: PMC10100976 DOI: 10.1128/spectrum.04361-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 12/12/2022] [Indexed: 02/01/2023] Open
Abstract
Dunaliella salina is the most salt-tolerant eukaryote and has the highest β-carotene content, but its carotenoid synthesis pathway is still unclear, especially the synthesis of lycopene, the upstream product of β-carotene. In this study, DsGGPS, DsPSY, DsPDS, DsZISO, DsZDS, DsCRTISO, and DsLYCB genes were cloned from D. salina and expressed in Escherichia coli. A series of carotenoid engineering E. coli strains from phytoene to β-carotene were obtained. ZISO was first identified from Chlorophyta, while CRTISO was first isolated from algae. It was found that DsZISO and DsCRTISO were essential for isomerization of carotenoids in photosynthetic organisms and could not be replaced by photoisomerization, unlike some plants. DsZDS was found to have weak beta cyclization abilities, and DsLYCB was able to catalyze 7,7',9,9'-tetra-cis-lycopene to generate 7,7',9,9'-tetra-cis-β-carotene, which had not been reported before. A new carotenoid 7,7',9,9'-tetra-cis-β-carotene, the beta cyclization product of prolycopene, was discovered. Compared with the bacterial-derived carotenoid synthesis pathway, there is higher specificity and greater efficiency of the carotenoid synthesis pathway in algae. This research experimentally confirmed that the conversion of phytoene to lycopene in D. salina was similar to that of plants and different from bacteria and provided a new possibility for the metabolic engineering of β-carotene. IMPORTANCE The synthesis mode of all trans-lycopene in bacteria and plants is clear, but there are still doubts in microalgae. Dunaliella is the organism with the highest β-carotene content, and plant-type and bacterial-type enzyme genes have been found in its carotenoid metabolism pathway. In this study, the entire plant-type enzyme gene was completely cloned into Escherichia coli, and high-efficiency expression was obtained, which proved that carotenoid synthesis of algae is similar to that of plants. In bacteria, CRT can directly catalyze 4-step continuous dehydrogenation to produce all trans-lycopene. In plants, four enzymes (PDS, ZISO, ZDS, and CRTISO) are involved in this process. Although a carotenoid synthetase similar to that of bacteria has been found in algae, it does not play a major role. This research reveals the evolutionary relationship of carotenoid metabolism in bacteria, algae, and plants and is of methodologically innovative significance for molecular evolution research.
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Affiliation(s)
- Hao-Hong Chen
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Ming-Hua Liang
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Zhi-Wei Ye
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - Yue-Hui Zhu
- Washington University School of Medicine, St. Louis, Missouri, USA
| | - Jian-Guo Jiang
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
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Zeballos N, Grulois D, Leung C, Chevin LM. Acceptable loss: Fitness consequences of salinity-induced cell death in a halotolerant microalga. Am Nat 2023; 201:825-840. [DOI: 10.1086/724417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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10
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Guermazi W, Masmoudi S, Trabelsi NA, Gammoudi S, Ayadi H, Morant-Manceau A, Hotos GN. Physiological and Biochemical Responses in Microalgae Dunaliella salina, Cylindrotheca closterium and Phormidium versicolor NCC466 Exposed to High Salinity and Irradiation. Life (Basel) 2023; 13:life13020313. [PMID: 36836671 PMCID: PMC9961930 DOI: 10.3390/life13020313] [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: 12/16/2022] [Revised: 01/16/2023] [Accepted: 01/19/2023] [Indexed: 01/24/2023] Open
Abstract
Dunaliella salina (Chlorophyceae), Phormidium versicolor (Cyanophyceae), and Cylindrotheca closterium (Bacillariophyceae) were isolated from three ponds in the solar saltern of Sfax (Tunisia). Growth, pigment contents, and photosynthetic and antioxidant enzyme activities were measured under controlled conditions of three light levels (300, 500, and 1000 µmol photons m-2 s-1) and three NaCl concentrations (40, 80, and 140 g L-1). The highest salinity reduced the growth of D. salina and P. versicolor NCC466 and strongly inhibited that of C. closterium. According to ΦPSII values, the photosynthetic apparatus of P. versicolor was stimulated by increasing salinity, whereas that of D. salina and C. closterium was decreased by irradiance rise. The production of carotenoids in D. salina and P. versicolor was stimulated when salinity and irradiance increased, whereas it decreased in the diatom. Catalase (CAT), Superoxide dismutase (SOD), and Ascorbate peroxidase (APX) activities were only detected when the three species were cultivated under E1000. The antioxidant activity of carotenoids could compensate for the low antioxidant enzyme activity measured in D. salina. Salinity and irradiation levels interact with the physiology of three species that have mechanisms of more or less effective stress resistance, hence different resistance to environmental stresses according to the species. Under these stress-controlled conditions, P. versicolor and C. closterium strains could provide promising sources of extremolyte for several purposes.
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Affiliation(s)
- Wassim Guermazi
- Laboratory of Marine Biodiversity and Environment (LR18ES/30), University of Sfax, Sfax CP 3000, Tunisia
| | - Salma Masmoudi
- Laboratory of Marine Biodiversity and Environment (LR18ES/30), University of Sfax, Sfax CP 3000, Tunisia
- LUNAM, Laboratoire Mer, Molécules, Santé (EA 2160), Université du Maine, Avenue Olivier Messiaen, CEDEX 9, 72085 Le Mans, France
| | - Neila Annabi Trabelsi
- Laboratory of Marine Biodiversity and Environment (LR18ES/30), University of Sfax, Sfax CP 3000, Tunisia
| | - Sana Gammoudi
- Laboratory of Marine Biodiversity and Environment (LR18ES/30), University of Sfax, Sfax CP 3000, Tunisia
| | - Habib Ayadi
- Laboratory of Marine Biodiversity and Environment (LR18ES/30), University of Sfax, Sfax CP 3000, Tunisia
| | - Annick Morant-Manceau
- LUNAM, Laboratoire Mer, Molécules, Santé (EA 2160), Université du Maine, Avenue Olivier Messiaen, CEDEX 9, 72085 Le Mans, France
| | - George N. Hotos
- Plankton Culture Laboratory, Department of Fisheries and Aquaculture, University of Patras, 30200 Messolonghi, Greece
- Correspondence:
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Metabolomic analysis reveals the responses of docosahexaenoic-acid-producing Schizochytrium under hyposalinity conditions. ALGAL RES 2023. [DOI: 10.1016/j.algal.2023.102987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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12
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Sokolov SS, Popova MM, Pohl P, Horner A, Akimov SA, Kireeva NA, Knorre DA, Batishchev OV, Severin FF. Structural Role of Plasma Membrane Sterols in Osmotic Stress Tolerance of Yeast Saccharomyces cerevisiae. MEMBRANES 2022; 12:1278. [PMID: 36557185 PMCID: PMC9781751 DOI: 10.3390/membranes12121278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/08/2022] [Accepted: 12/15/2022] [Indexed: 06/17/2023]
Abstract
Yeast S. cerevisiae has been shown to suppress a sterol biosynthesis as a response to hyperosmotic stress. In the case of sodium stress, the failure to suppress biosynthesis leads to an increase in cytosolic sodium. The major yeast sterol, ergosterol, is known to regulate functioning of plasma membrane proteins. Therefore, it has been suggested that the suppression of its biosynthesis is needed to adjust the activity of the plasma membrane sodium pumps and channels. However, as the sterol concentration is in the range of thirty to forty percent of total plasma membrane lipids, it is believed that its primary biological role is not regulatory but structural. Here we studied how lowering the sterol content affects the response of a lipid bilayer to an osmotic stress. In accordance with previous observations, we found that a decrease of the sterol fraction increases a water permeability of the liposomal membranes. Yet, we also found that sterol-free giant unilamellar vesicles reduced their volume during transient application of the hyperosmotic stress to a greater extent than the sterol-rich ones. Furthermore, our data suggest that lowering the sterol content in yeast cells allows the shrinkage to prevent the osmotic pressure-induced plasma membrane rupture. We also found that mutant yeast cells with the elevated level of sterol accumulated propidium iodide when exposed to mild hyperosmotic conditions followed by hypoosmotic stress. It is likely that the decrease in a plasma membrane sterol content stimulates a drop in cell volume under hyperosmotic stress, which is beneficial in the case of a subsequent hypo-osmotic one.
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Affiliation(s)
- Svyatoslav S. Sokolov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 1-40 Leninskie Gory, 119991 Moscow, Russia
| | - Marina M. Popova
- Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31/4 Leninskiyprospekt, 119071 Moscow, Russia
| | - Peter Pohl
- Institute of Biophysics, Johannes Kepler University Linz, Gruberstraße 40, 4020 Linz, Austria
| | - Andreas Horner
- Institute of Biophysics, Johannes Kepler University Linz, Gruberstraße 40, 4020 Linz, Austria
| | - Sergey A. Akimov
- Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31/4 Leninskiyprospekt, 119071 Moscow, Russia
| | - Natalia A. Kireeva
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 1-40 Leninskie Gory, 119991 Moscow, Russia
| | - Dmitry A. Knorre
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 1-40 Leninskie Gory, 119991 Moscow, Russia
| | - Oleg V. Batishchev
- Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31/4 Leninskiyprospekt, 119071 Moscow, Russia
| | - Fedor F. Severin
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 1-40 Leninskie Gory, 119991 Moscow, Russia
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Fierli D, Barone ME, Graceffa V, Touzet N. Cold stress combined with salt or abscisic acid supplementation enhances lipogenesis and carotenogenesis in Phaeodactylum tricornutum (Bacillariophyceae). Bioprocess Biosyst Eng 2022; 45:1967-1977. [PMID: 36264371 DOI: 10.1007/s00449-022-02800-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 10/07/2022] [Indexed: 11/02/2022]
Abstract
Compounds from microalgae such as ω3-fatty acids or carotenoid are commercially exploited within the pharmacology, nutraceutical, or cosmetic sectors. The co-stimulation of several compounds of interest may improve the cost-effectiveness of microalgal biorefinery pipelines. This study focussed on Phaeodactylum tricornutum to investigate the effects on lipogenesis and carotenogenesis of combined stressors, here cold temperature and addition of NaCl salt or the phytohormone abscisic acid, using a two-stage cultivation strategy. Cold stress with NaCl or phytohormone addition increased the neutral lipid content of the biomass (20 to 35%). These treatments also enhanced the proportions of EPA (22% greater than control) in the fatty acid profile. Also, these treatments had a stimulatory effect on carotenogenesis, especially the combination of cold stress with NaCl addition, which returned the highest production of fucoxanthin (33% increase). The gene expression of diacylglycerol acyltransferase (DGAT) and the ω-3 desaturase precursor (PTD15) were enhanced 4- and 16-fold relative to the control, respectively. In addition, zeaxanthin epoxidase 3 (ZEP3), was downregulated at low temperature when combined with abscisic acid. These results highlight the benefits of applying a combination of low temperature and salinity stress, to simultaneously enhance the yields of the valuable metabolites EPA and fucoxanthin in Phaeodactylum tricornutum.
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Affiliation(s)
- David Fierli
- School of Science, Department of Environmental Science, Centre for Environmental Research, Sustainability and Innovation, Atlantic Technological University, Ash Ln, Ballytivnan, Sligo, F91 YW50, Ireland.
| | - Maria Elena Barone
- School of Science, Department of Environmental Science, Centre for Environmental Research, Sustainability and Innovation, Atlantic Technological University, Ash Ln, Ballytivnan, Sligo, F91 YW50, Ireland
| | - Valeria Graceffa
- School of Science, Department of Life Sciences, Cellular Health and Toxicology Research Group (CHAT), Atlantic Technological University, Ash Ln, Ballytivnan, Sligo, F91 YW50, Ireland
| | - Nicolas Touzet
- School of Science, Department of Environmental Science, Centre for Environmental Research, Sustainability and Innovation, Atlantic Technological University, Ash Ln, Ballytivnan, Sligo, F91 YW50, Ireland
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He Z, Liu D, Shi Y, Wu X, Dai Y, Shang Y, Peng J, Cui Z. Broader environmental adaptation of rare rather than abundant bacteria in reforestation succession soil. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 828:154364. [PMID: 35288131 DOI: 10.1016/j.scitotenv.2022.154364] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 01/07/2022] [Accepted: 03/03/2022] [Indexed: 06/14/2023]
Abstract
Revealing the responses of rare and abundant bacteria to environmental change is crucial for understanding microbial community assembly and ecosystem function. However, both the environmental adaptability and the ecological assembly processes exhibited by rare and abundant soil bacteria remain poorly understood. Here we investigated the assembly processes of rare and abundant bacteria along a chronosequence of a 35-year reforestation succession (8, 17, and 35 years), particularly with regard to their environmental adaptations. Compared to the abundant taxa, the phylogenetic clustering of rare taxa was tighter but their environmental breadth wider. Homogeneous selection (65.8%) belonging to deterministic processes dominated the rare bacterial assembly, whereas homogenizing dispersal and undominated process (57.9%) belonging to stochastic processes governed the abundant taxa. Neutral processes had a significant impact on shaping the rare taxa compared to the abundant taxa. Rare taxa were environmentally less constrained than abundant taxa. Soil EC was the major determinant factor for the assembly processes of both rare and abundant taxa. Ecological assembly processes showed a significant negative correlation with rare bacterial functional redundancies, while they had a significant positive correlation with the abundant taxa. Microbial network modularity further demonstrated that rare taxa developed stronger environmental adaptation strategies than their abundant counterparts. Our study significantly advances the knowledge of the environmental adaptability of rare and abundant bacteria and emphasizes their key role in reforestation ecological succession soils.
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Affiliation(s)
- Zhibin He
- College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, 100193, China
| | - Duo Liu
- College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, 100193, China
| | - Yu Shi
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, Henan, China
| | - Xingjie Wu
- College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, 100193, China
| | - Yuexiu Dai
- College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, 100193, China
| | - Yiwei Shang
- College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, 100193, China
| | - Jingjing Peng
- College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, 100193, China.
| | - Zhenling Cui
- College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, 100193, China
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15
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Leung C, Grulois D, Chevin LM. Plasticity across levels: relating epigenomic, transcriptomic, and phenotypic responses to osmotic stress in a halotolerant microalga. Mol Ecol 2022; 31:4672-4687. [PMID: 35593517 PMCID: PMC9543585 DOI: 10.1111/mec.16542] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Accepted: 05/12/2022] [Indexed: 12/01/2022]
Abstract
Phenotypic plasticity, the ability of a given genotype to produce alternative phenotypes in response to its environment of development, is an important mechanism for coping with variable environments. While the mechanisms underlying phenotypic plasticity are diverse, their relative contributions need to be investigated quantitatively to better understand the evolvability of plasticity across biological levels. This requires relating plastic responses of the epigenome, transcriptome, and organismal phenotype, and investigating how they vary with the genotype. Here we carried out this approach for responses to osmotic stress in Dunaliella salina, a green microalga that is a model organism for salinity tolerance. We compared two strains that show markedly different demographic responses to osmotic stress, and showed that these phenotypic responses involve strain‐ and environment‐specific variation in gene expression levels, but a relative low—albeit significant—effect of strain × environment interaction. We also found an important genotype effect on the genome‐wide methylation pattern, but little contribution from environmental conditions to the latter. However, we did detect a significant marginal effect of epigenetic variation on gene expression, beyond the influence of genetic differences on epigenetic state, and we showed that hypomethylated regions are correlated with higher gene expression. Our results indicate that epigenetic mechanisms are either not involved in the rapid plastic response to environmental change in this species, or involve only few changes in trans that are sufficient to trigger concerted changes in the expression of many genes, and phenotypic responses by multiple traits.
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Affiliation(s)
- Christelle Leung
- CEFE, Université de Montpellier, CNRS, EPHE, IRD, Montpellier, France
| | - Daphné Grulois
- CEFE, Université de Montpellier, CNRS, EPHE, IRD, Montpellier, France
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Xu L, Gao F, Feng J, Lv J, Liu Q, Nan F, Liu X, Xie S. Relationship between β-Carotene Accumulation and Geranylgeranyl Pyrophosphate Synthase in Different Species of Dunaliella. PLANTS (BASEL, SWITZERLAND) 2021; 11:27. [PMID: 35009031 PMCID: PMC8747272 DOI: 10.3390/plants11010027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 12/14/2021] [Accepted: 12/20/2021] [Indexed: 06/14/2023]
Abstract
To study the relationship between β-carotene synthesis and geranylgeranyl pyrophosphate synthase (GGPS) activity, 15 species of Dunaliella were used to determine the changes in photosynthetic pigment contents, chlorophyll fluorescence parameters, β-carotene content, and GGPS activity. By observing the morphology and size of 15 species of Dunaliella, D8 has the largest individual algal cell and D9 has the smallest individual. Growth was relatively slow during days one through seven. After about eight days, the cells entered the logarithmic growth period and grew rapidly to a high density. After about 45 days, they entered a mature period, and growth slowed down. The contents of chlorophyll, carotenoids, and β-carotene increased during growth. D1 has the highest accumulation of β-carotene, and GGPS enzyme activity has a positive linear relationship with the β-carotene synthesis content. Phylogenetic analysis showed that the GGPS proteins of the 15 species were highly homologous, and the GGPS protein was not part of the membrane.
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Capa-Robles W, García-Mendoza E, Paniagua-Michel JDJ. Enhanced β-carotene and Biomass Production by Induced Mixotrophy in Dunaliella salina across a Combined Strategy of Glycerol, Salinity, and Light. Metabolites 2021; 11:metabo11120866. [PMID: 34940624 PMCID: PMC8708783 DOI: 10.3390/metabo11120866] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/03/2021] [Accepted: 12/09/2021] [Indexed: 11/24/2022] Open
Abstract
Current mixotrophic culture systems for Dunaliella salina have technical limitations to achieve high growth and productivity. The purpose of this study was to optimize the mixotrophic conditions imposed by glycerol, light, and salinity that lead to the highest biomass and β-carotene yields in D. salina. The combination of 12.5 mM glycerol, 3.0 M salinity, and 50 μmol photons m−2 s−1 light intensity enabled significant assimilation of glycerol by D. salina and consequently enhanced growth (2.1 × 106 cell mL−1) and β-carotene accumulation (4.43 pg cell−1). The saline and light shock induced the assimilation of glycerol by this microalga. At last stage of growth, the increase in light intensity (300 μmol photons m−2 s−1) caused the β-carotene to reach values higher than 30 pg cell−1 and tripled the β-carotene values obtained from photoautotrophic cultures using the same light intensity. Increasing the salt concentration from 1.5 to 3.0 M NaCl (non-isosmotic salinity) produced higher growth and microalgal β-carotene than the isosmotic salinity 3.0 M NaCl. The mixotrophic strategy developed in this work is evidenced in the metabolic capability of D. salina to use both photosynthesis and organic carbon, viz., glycerol that leads to higher biomass and β-carotene productivity than that of an either phototrophic or heterotrophic process alone. The findings provide insights into the key role of exogenous glycerol with a strategic combination of salinity and light, which evidenced unknown roles of this polyol other than that in osmoregulation, mainly on the growth, pigment accumulation, and carotenogenesis of D. salina.
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Affiliation(s)
- Willian Capa-Robles
- Department of Marine Biotechnology, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), 22860 Ensenada, Baja California, Mexico;
| | - Ernesto García-Mendoza
- Department of Biological Oceanography, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), 22860 Ensenada, Baja California, Mexico;
| | - José de Jesús Paniagua-Michel
- Department of Marine Biotechnology, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), 22860 Ensenada, Baja California, Mexico;
- Correspondence: ; Tel.: +52-646-1745050
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Govaert L, Gilarranz LJ, Altermatt F. Competition alters species' plastic and genetic response to environmental change. Sci Rep 2021; 11:23518. [PMID: 34876603 PMCID: PMC8651732 DOI: 10.1038/s41598-021-02841-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 11/18/2021] [Indexed: 11/29/2022] Open
Abstract
Species react to environmental change via plastic and evolutionary responses. While both of them determine species' survival, most studies quantify these responses individually. As species occur in communities, competing species may further influence their respective response to environmental change. Yet, how environmental change and competing species combined shape plastic and genetic responses to environmental change remains unclear. Quantifying how competition alters plastic and genetic responses of species to environmental change requires a trait-based, community and evolutionary ecological approach. We exposed unicellular aquatic organisms to long-term selection of increasing salinity-representing a common and relevant environmental change. We assessed plastic and genetic contributions to phenotypic change in biomass, cell shape, and dispersal ability along increasing levels of salinity in the presence and absence of competition. Trait changes in response to salinity were mainly due to mean trait evolution, and differed whether species evolved in the presence or absence of competition. Our results show that species' evolutionary and plastic responses to environmental change depended both on competition and the magnitude of environmental change, ultimately determining species persistence. Our results suggest that understanding plastic and genetic responses to environmental change within a community will improve predictions of species' persistence to environmental change.
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Affiliation(s)
- Lynn Govaert
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland. .,Department of Aquatic Ecology, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, 8600, Dübendorf, Switzerland. .,URPP Global Change and Biodiversity, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland. .,Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 310, 12587, Berlin, Germany.
| | - Luis J. Gilarranz
- grid.418656.80000 0001 1551 0562Department of Aquatic Ecology, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, 8600 Dübendorf, Switzerland
| | - Florian Altermatt
- grid.7400.30000 0004 1937 0650Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland ,grid.418656.80000 0001 1551 0562Department of Aquatic Ecology, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, 8600 Dübendorf, Switzerland ,grid.7400.30000 0004 1937 0650URPP Global Change and Biodiversity, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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Gao F, Nan F, Feng J, Lv J, Liu Q, Liu X, Xie S. Comparative morphological, physiological, biochemical and genomic studies reveal novel genes of Dunaliella bioculata and D. quartolecta in response to salt stress. Mol Biol Rep 2021; 49:1749-1761. [PMID: 34813000 DOI: 10.1007/s11033-021-06984-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 11/18/2021] [Indexed: 11/24/2022]
Abstract
BACKGROUND Salinity is an essential abiotic stress in plants. Dunaliella is a genus of high-salt-tolerant microalgae. The present study aimed to compare the characterizations of D. bioculata and D. quartolecta at different levels and investigate novel genes response to salt stress. METHODS AND RESULTS High chlorophyll contents were detected in D. bioculata on the 35th d of salt stress, while high lipid and carotenoid contents were detected in D. quartolecta via morphological and biochemical analyses. Physiological analysis showed that D. quartolecta cells had a smaller increase in osmotic potential, a smaller decrease in the Na+/K+ ratio and photochemical efficiency (Fv/Fm), and a lower relative conductivity than D. bioculata cells. The genomic lengths of D. quartolecta and D. bioculata were 396,013,629 bp (scaffold N50 = 1954 bp) and 427,667,563 bp (scaffold N50 = 3093 bp) via high-throughput sequencing and de novo assembly, respectively. Altogether, 25,751 and 26,620 genes were predicted in their genomes by annotation analysis with various biodatabases. The D. bioculata genome showed more segmental duplication events via collinearity analysis. More single nucleotide polymorphisms and insertion-deletion variants were detected in the D. bioculata genome. Both algae, which showed a close phylogenetic relationship, may undergo positive selection via bioinformatics analysis. A total of 382 and 85 novel genes were screened in D. bioculata and D. quartolecta, with 138 and 51 enriched KEGG pathways, respectively. Unlike the novel genes adh1, hprA and serA, the relative expression of livF and phbB in D. bioculata was markedly downregulated as salinity increased, as determined by qPCR analysis. The relative expression of leuB, asd, pstC and proA in D. quartolecta was markedly upregulated with the same salinity increase. CONCLUSION Dunaliella quartolecta is more halophilic than D. bioculata, with more effective responses to high salt stress based on the multiphase comparative data.
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Affiliation(s)
- Fan Gao
- School of Life Science, Shanxi Key Laboratory for Research and Development of Regional Plants, Shanxi University, No. 92 Wucheng Road, Taiyuan, 030006, China
| | - Fangru Nan
- School of Life Science, Shanxi Key Laboratory for Research and Development of Regional Plants, Shanxi University, No. 92 Wucheng Road, Taiyuan, 030006, China
| | - Jia Feng
- School of Life Science, Shanxi Key Laboratory for Research and Development of Regional Plants, Shanxi University, No. 92 Wucheng Road, Taiyuan, 030006, China
| | - Junping Lv
- School of Life Science, Shanxi Key Laboratory for Research and Development of Regional Plants, Shanxi University, No. 92 Wucheng Road, Taiyuan, 030006, China
| | - Qi Liu
- School of Life Science, Shanxi Key Laboratory for Research and Development of Regional Plants, Shanxi University, No. 92 Wucheng Road, Taiyuan, 030006, China
| | - Xudong Liu
- School of Life Science, Shanxi Key Laboratory for Research and Development of Regional Plants, Shanxi University, No. 92 Wucheng Road, Taiyuan, 030006, China
| | - Shulian Xie
- School of Life Science, Shanxi Key Laboratory for Research and Development of Regional Plants, Shanxi University, No. 92 Wucheng Road, Taiyuan, 030006, China.
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20
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Li Y, Wang L, Yu B, Guo J, Zhao Y, Zhu Y. Expression Analysis of AUX/IAA Family Genes in Apple Under Salt Stress. Biochem Genet 2021; 60:1205-1221. [PMID: 34802110 DOI: 10.1007/s10528-021-10158-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 11/10/2021] [Indexed: 11/26/2022]
Abstract
Members of the auxin/indoleacetic acid (Aux/IAA) gene family in plants are primary auxin-responsive genes that play important roles in many aspects of plant development and in responses to abiotic stress. Recently, 33 Aux/IAA have been identified in the apple genome. The biological responses of MdIAAs to salt stress are still unknown. In this study, Malus zumi, Malus baccata, and Malus × domestica 'Fuji' plantlets were subjected to salt stress by supplementing hydroponic media with NaCl at various concentrations. M. zumi showed the strongest salt resistance, followed by 'Fuji', and M. baccata was the most sensitive to salt stress. Tissue-specific expression profiles of MdIAAs were determined by quantitative real-time polymerase chain reaction. When apple plantlets were subjected to salt stress, most of salt-responsive MdIAAs were up-regulated by 1 h, 3 h, and 6 h in roots, shoot tips, and leaves, respectively. Highly expressed MdIAAs in roots, especially for M. zumi, consisted with the salt tolerance of apple rootstocks. Transgenic apple calli were tolerant to salt stress when over-expressed salt-responsive genes, MdIAA8, -9, and -25. These results provide clues about salt resistance in these three Malus species, which helps apple breeding of salt tolerance by genetic transformation.
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Affiliation(s)
- Yongzhou Li
- Department of Pomology, College of Horticulture, China Agricultural University, Yuanmingyuan West Road No. 2, Haidian District, Beijing, 100193, People's Republic of China
| | - Limin Wang
- Department of Pomology, College of Horticulture, China Agricultural University, Yuanmingyuan West Road No. 2, Haidian District, Beijing, 100193, People's Republic of China
| | - Boyang Yu
- Department of Pomology, College of Horticulture, China Agricultural University, Yuanmingyuan West Road No. 2, Haidian District, Beijing, 100193, People's Republic of China
| | - Jing Guo
- Department of Pomology, College of Horticulture, China Agricultural University, Yuanmingyuan West Road No. 2, Haidian District, Beijing, 100193, People's Republic of China
| | - Yanan Zhao
- Department of Pomology, College of Horticulture, China Agricultural University, Yuanmingyuan West Road No. 2, Haidian District, Beijing, 100193, People's Republic of China
| | - Yuandi Zhu
- Department of Pomology, College of Horticulture, China Agricultural University, Yuanmingyuan West Road No. 2, Haidian District, Beijing, 100193, People's Republic of China.
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21
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Kumar Patel A, Tseng YS, Rani Singhania R, Chen CW, Chang JS, Di Dong C. Novel application of microalgae platform for biodesalination process: A review. BIORESOURCE TECHNOLOGY 2021; 337:125343. [PMID: 34120057 DOI: 10.1016/j.biortech.2021.125343] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 05/24/2021] [Accepted: 05/26/2021] [Indexed: 06/12/2023]
Abstract
Freshwater demand is rising worldwide due to largely increasing population and industrialization. Latest focus is to explore the Ocean and saline effluent from industries to produce freshwater in a sustainable way via algal desalination. Current physicochemical desalination technology is not only an energy-intensive and expensive process but also gives severe environmental impact from brine and GHGs emissions. Therefore, it is neither environmentally-friendly nor feasible to countries with limited resources. Biodesalination could be an attractive technology with recent breakthroughs in algal bioprocess with fast growth rate under highly saline conditions to effectively remove salts optimally 50-67% from saline water. Algal desalination mainly occurs through biosorption and bioaccumulation which governs by biotic and abiotic factors e.g., strain, temperature, pH, light and nutrients etc. This review provides a current scenario of this novel technology by an in-depth assessment of technological advancement, social impact, possible risks and scope for policy implications.
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Affiliation(s)
- Anil Kumar Patel
- Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City 81157 Taiwan
| | - Yi-Sheng Tseng
- Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City 81157 Taiwan
| | - Reeta Rani Singhania
- Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City 81157 Taiwan
| | - Chiu-Wen Chen
- Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City 81157 Taiwan
| | - Jo-Shu Chang
- Department of Chemical and Materials Engineering, Tunghai University, Taiwan; Research Center for Smart Sustainable Circular Economy, Tunghai University, Taiwan; Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan
| | - Cheng Di Dong
- Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City 81157 Taiwan.
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22
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Skjånes K, Aesoy R, Herfindal L, Skomedal H. Bioactive peptides from microalgae: Focus on anti-cancer and immunomodulating activity. PHYSIOLOGIA PLANTARUM 2021; 173:612-623. [PMID: 34085279 DOI: 10.1111/ppl.13472] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 05/06/2021] [Accepted: 05/31/2021] [Indexed: 06/12/2023]
Abstract
In addition to the rapidly expanding field of using microalgae for food and feed, microalgae represent a tremendous potential for new bioactive compounds with health-promoting effects. One field where new therapeutics is needed is cancer therapy. As cancer therapy often cause severe side effects and loose effect due to development of drug resistance, new therapeutic agents are needed. Treating cancer by modulating the immune response using peptides has led to unprecedented responses in patients. In this review, we want to elucidate the potential for microalgae as a source of new peptides for possible use in cancer management. Among the limited studies on anti-cancer effects of peptides, positive results were found in a total of six different forms of cancer. The majority of studies have been performed with different strains of Chlorella, but effects have also been found using peptides from other species. This is also the case for peptides with immunomodulating effects and peptides with other health-promoting effects (e.g., role in cardiovascular diseases). However, the active peptide sequence has been determined in only half of the studies. In many cases, the microalga strain and the cultivation conditions used for producing the algae have not been reported. The low number of species that have been explored, as opposed to the large number of species available, is a clear indication that the potential for new discoveries is large. Additionally, the availability and cost-effectiveness of microalgae make them attractive in the search for bioactive peptides to prevent cancer.
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Affiliation(s)
- Kari Skjånes
- Division of Biotechnology and Plant Health, Norwegian Institute of Bioeconomy Research (NIBIO), Ås, Norway
| | - Reidun Aesoy
- Department of Clinical Science, Centre for Pharmacy, University of Bergen, Bergen, Norway
| | - Lars Herfindal
- Department of Clinical Science, Centre for Pharmacy, University of Bergen, Bergen, Norway
| | - Hanne Skomedal
- Division of Biotechnology and Plant Health, Norwegian Institute of Bioeconomy Research (NIBIO), Ås, Norway
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Utilisation of CO2 from Sodium Bicarbonate to Produce Chlorella vulgaris Biomass in Tubular Photobioreactors for Biofuel Purposes. SUSTAINABILITY 2021. [DOI: 10.3390/su13169118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Microalgae are one of the most promising sources of renewable substrates used for energy purposes. Biomass and components accumulated in their cells can be used to produce a wide range of biofuels, but the profitability of their production is still not at a sufficient level. Significant costs are generated, i.a., during the cultivation of microalgae, and are connected with providing suitable culture conditions. This study aims to evaluate the possibility of using sodium bicarbonate as an inexpensive alternative CO2 source in the culture of Chlorella vulgaris, promoting not only the increase of microalgae biomass production but also lipid accumulation. The study was carried out at technical scale using 100 L photobioreactors. Gravimetric and spectrophotometric methods were used to evaluate biomass growth. Lipid content was determined using a mixture of chloroform and methanol according to the Blight and Dyer method, while the carbon content and CO2 fixation rate were measured according to the Walkley and Black method. In batch culture, even a small addition of bicarbonate resulted in a significant (p ≤ 0.05) increase in the amount of biomass, productivity and optical density compared to non-bicarbonate cultures. At 2.0 g∙L–1, biomass content was 572 ± 4 mg·L−1, the maximum productivity was 7.0 ± 1.0 mg·L–1·d–1, and the optical density was 0.181 ± 0.00. There was also an increase in the lipid content (26 ± 4%) and the carbon content in the biomass (1322 ± 0.062 g∙dw–1), as well as a higher rate of carbon dioxide fixation (0.925 ± 0.073 g·L–1·d–1). The cultivation of microalgae in enlarged scale photobioreactors provides a significant technological challenge. The obtained results can be useful to evaluate the efficiency of biomass and valuable cellular components production in closed systems realized at industrial scale.
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Abu-Ghosh S, Dubinsky Z, Verdelho V, Iluz D. Unconventional high-value products from microalgae: A review. BIORESOURCE TECHNOLOGY 2021; 329:124895. [PMID: 33713898 DOI: 10.1016/j.biortech.2021.124895] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/18/2021] [Accepted: 02/19/2021] [Indexed: 06/12/2023]
Abstract
Microalgae have gained significant importance in biotechnology development, providing valuable goods and services in multiple applications. Although there is a rising market for most of these applications, the incorporation and introduction of microalgae into new venues will extend in the near future. These advances are due to the vast biodiversity of microalgal species, recent genetic engineering tools, and culture techniques. There are three main possible approaches for novel algal compounds from: (1) recently isolated yet less known microalgae; (2) selectively stressed conditions; and (3) enzymatically adjusted compounds from conventional molecules. All these approaches can be combined in a specific manner. This review discusses the opportunities, potential and limitations of introducing novel microalgae-based products, and how the recent technologies can be deployed to make these products financially viable. To give an outlook to the future, an analysis of the developments and predicted future market that further enlarge the promise of cultivating microalgae for commercial purposes are considered.
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Affiliation(s)
- Said Abu-Ghosh
- The Mina and Everard Goodman, Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
| | - Zvy Dubinsky
- The Mina and Everard Goodman, Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Vitor Verdelho
- General Manager of the European Algae Biomass Association (EABA), Portugal
| | - David Iluz
- The Mina and Everard Goodman, Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel; Department of Environmental Sciences and Agriculture, Beit Berl Academic College, Israel; Talpiot academic College, Holon, Israel
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Abstract
Microalgae have become an attractive natural source of a diverse range of biomolecules, including enzymatic and non-enzymatic antioxidants; nevertheless, economically sustainable production of such compounds from microalgae biomass is still challenging. The main hurdles are: (a) increasing microalgae yield; (b) achieving optimal cultivation conditions; (c) energy-efficient and cost-effective downstream processing (extraction and purification); (d) optimal storage of post-processed antioxidant molecules. This review provides a detailed overview of enzymatic and non-enzymatic antioxidants in the cellular metabolism of the commercially important microalgae Dunaliella, industrial applications of antioxidant enzymes, strategies to enhanced antioxidant accumulation in cells, and the opportunities and limitations of current technologies for antioxidant enzymes production from microalgae biomass as an alternative to common microbial sources.
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Villanova V, Galasso C, Fiorini F, Lima S, Brönstrup M, Sansone C, Brunet C, Brucato A, Scargiali F. Biological and chemical characterization of new isolated halophilic microorganisms from saltern ponds of Trapani, Sicily. ALGAL RES 2021. [DOI: 10.1016/j.algal.2021.102192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Wan W, Liu S, Li X, Xing Y, Chen W, Huang Q. Bridging Rare and Abundant Bacteria with Ecosystem Multifunctionality in Salinized Agricultural Soils: from Community Diversity to Environmental Adaptation. mSystems 2021; 6:e01221-20. [PMID: 33785569 PMCID: PMC8547000 DOI: 10.1128/msystems.01221-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/03/2021] [Indexed: 01/09/2023] Open
Abstract
Bacterial diversity and ecosystem multifunctionality (EMF) vary along environmental gradients. However, little is known about interconnections between EMF and taxonomic and phylogenetic diversities of rare and abundant bacteria. Using MiSeq sequencing and multiple statistical analyses, we evaluated the maintenance of taxonomic and phylogenetic diversities of rare and abundant bacteria and their contributions to EMF in salinized agricultural soils (0.09 to 19.91 dS/m). Rare bacteria exhibited closer phylogenetic clustering and broader environmental breadths than abundant ones, while abundant bacteria showed higher functional redundancies and stronger phylogenetic signals of ecological preferences than rare ones. Variable selection (86.7%) dominated rare bacterial community assembly, and dispersal limitation (54.7%) and variable selection (24.5%) determined abundant bacterial community assembly. Salinity played a decisive role in mediating the balance between stochastic and deterministic processes and showed significant effects on functions and diversities of both rare and abundant bacteria. Rare bacterial taxonomic α-diversity and abundant bacterial phylogenetic α-diversity contributed significantly to EMF, while abundant bacterial taxonomic α-diversity and rare bacterial phylogenetic α-diversity did not. Additionally, abundant rather than rare bacterial community function had a significant effect on soil EMF. These findings extend our knowledge of environmental adaptation of rare and abundant bacteria and highlight different contributions of taxonomic and phylogenetic α-diversities of rare and abundant bacteria to soil EMF.IMPORTANCE Soil salinization is a worldwide environmental problem and threatens plant productivity and microbial diversity. Understanding the generation and maintenance of microbial diversity is essential to estimate soil tillage potential via investigating ecosystem multifunctionality. Our sequence-based data showed differences in environmental adaptations of rare and abundant bacteria at taxonomic and phylogenetic levels, which led to different contributions of taxonomic and phylogenetic α-diversities of rare and abundant bacteria to soil EMF. Studying the diversity of rare and abundant bacteria and their contributions to EMF in salinized soils is critical for guiding soil restoration.
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Affiliation(s)
- Wenjie Wan
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, People's Republic of China
- Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, People's Republic of China
| | - Song Liu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, People's Republic of China
| | - Xiang Li
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, People's Republic of China
| | - Yonghui Xing
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, People's Republic of China
| | - Wenli Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, People's Republic of China
| | - Qiaoyun Huang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, People's Republic of China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, Huazhong Agricultural University, Wuhan, People's Republic of China
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Lv H, Kim M, Park S, Baek K, Oh H, Polle JE, Jin E. Comparative transcriptome analysis of short-term responses to salt and glycerol hyperosmotic stress in the green alga Dunaliella salina. ALGAL RES 2021. [DOI: 10.1016/j.algal.2020.102147] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Capability of carbon fixation in bicarbonate-based and carbon dioxide-based systems by Scenedesmus acuminatus TH04. Biochem Eng J 2021. [DOI: 10.1016/j.bej.2020.107858] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Lipid accumulation patterns and role of different fatty acid types towards mitigating salinity fluctuations in Chlorella vulgaris. Sci Rep 2021; 11:438. [PMID: 33432049 PMCID: PMC7801682 DOI: 10.1038/s41598-020-79950-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 12/15/2020] [Indexed: 12/12/2022] Open
Abstract
Mangrove-dwelling microalgae are well adapted to frequent encounters of salinity fluctuations across their various growth phases but are lesser studied. The current study explored the adaptive changes (in terms of biomass, oil content and fatty acid composition) of mangrove-isolated C. vulgaris UMT-M1 cultured under different salinity levels (5, 10, 15, 20, 30 ppt). The highest total oil content was recorded in cultures at 15 ppt salinity (63.5% of dry weight) with uncompromised biomass productivity, thus highlighting the ‘trigger-threshold’ for oil accumulation in C. vulgaris UMT-M1. Subsequently, C. vulgaris UMT-M1 was further assessed across different growth phases under 15 ppt. The various short, medium and long-chain fatty acids (particularly C20:0), coupled with a high level of C18:3n3 PUFA reported at early exponential phase represents their physiological importance during rapid cell growth. Accumulation of C18:1 and C18:2 at stationary growth phase across all salinities was seen as cells accumulating substrate for C18:3n3 should the cells anticipate a move from stationary phase into new growth phase. This study sheds some light on the possibility of ‘triggered’ oil accumulation with uninterrupted growth and the participation of various fatty acid types upon salinity mitigation in a mangrove-dwelling microalgae.
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Polle JE, Calhoun S, McKie-Krisberg Z, Prochnik S, Neofotis P, Yim WC, Hathwaik LT, Jenkins J, Molina H, Bunkenborg J, Grigoriev IV, Barry K, Schmutz J, Jin E, Cushman JC, Magnusson JK. Genomic adaptations of the green alga Dunaliella salina to life under high salinity. ALGAL RES 2020. [DOI: 10.1016/j.algal.2020.101990] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Leung C, Rescan M, Grulois D, Chevin LM. Reduced phenotypic plasticity evolves in less predictable environments. Ecol Lett 2020; 23:1664-1672. [PMID: 32869431 PMCID: PMC7754491 DOI: 10.1111/ele.13598] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/22/2020] [Accepted: 08/06/2020] [Indexed: 01/16/2023]
Abstract
Phenotypic plasticity is a prominent mechanism for coping with variable environments, and a key determinant of extinction risk. Evolutionary theory predicts that phenotypic plasticity should evolve to lower levels in environments that fluctuate less predictably, because they induce mismatches between plastic responses and selective pressures. However, this prediction is difficult to test in nature, where environmental predictability is not controlled. Here, we exposed 32 lines of the halotolerant microalga Dunaliella salina to ecologically realistic, randomly fluctuating salinity, with varying levels of predictability, for 500 generations. We found that morphological plasticity evolved to lower degrees in lines that experienced less predictable environments. Evolution of plasticity mostly concerned phases with slow population growth, rather than the exponential phase where microbes are typically phenotyped. This study underlines that long‐term experiments with complex patterns of environmental change are needed to test theories about population responses to altered environmental predictability, as currently observed under climate change.
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Affiliation(s)
- Christelle Leung
- CEFE, Université de Montpellier, CNRS, EPHE, IRD, Université Paul Valéry Montpellier 3, Montpellier, France
| | - Marie Rescan
- CEFE, Université de Montpellier, CNRS, EPHE, IRD, Université Paul Valéry Montpellier 3, Montpellier, France
| | - Daphné Grulois
- CEFE, Université de Montpellier, CNRS, EPHE, IRD, Université Paul Valéry Montpellier 3, Montpellier, France
| | - Luis-Miguel Chevin
- CEFE, Université de Montpellier, CNRS, EPHE, IRD, Université Paul Valéry Montpellier 3, Montpellier, France
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Xu F, Pan J. Potassium channel KCN11 is required for maintaining cellular osmolarity during nitrogen starvation to control proper cell physiology and TAG accumulation in Chlamydomonas reinhardtii. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:129. [PMID: 32699552 PMCID: PMC7372795 DOI: 10.1186/s13068-020-01769-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 07/11/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Nitrogen (N) starvation in algae induces a variety of structural and metabolic changes including accumulation of triacylglycerol (TAG). Given the promising prospect of using algae as feedstock for biofuel production, accumulation of TAG upon N starvation becomes an ideal system to study TAG biosynthesis. Under nitrogen-depleted conditions, algae also accumulate compatible solutes such as sugar and certain amino acids, which is expected to elevate osmolarity in the cytoplasm. However, how osmoregulation is maintained and how it impacts on carbon metabolism, especially TAG accumulation under N starvation, are not well understood. RESULTS We show here that potassium channel KCN11 localized in the contractile vacuole (CV) mediates osmoregulation during N starvation and loss of KCN11 profoundly affects cell physiology and TAG biosynthesis. KCN11 level is increased and the CV pulsation is accelerated. Loss of KCN11 induces aberrant CV cycle, inhibition of cell growth, increase of cell size, inhibition of chlorophyll loss and TAG accumulation. These effects are rescued by addition of sucrose to raise osmolarity in the culture medium, indicating that osmoregulation is required for cell adaptation to N starvation. Metabolomic analysis shows reduction of acetyl-CoA and accumulation of glyceraldehyde-3-phosphate in kcn11 mutant relative to the control under N starvation, indicating that defects in acetyl-CoA biosynthesis and some metabolic steps from glyceraldehyde-3-phosphate to TAG contribute to the decreased TAG accumulation due to loss of osmoregulation. CONCLUSIONS This work provides novel insight of osmoregulation during N starvation in the control of cell physiology and metabolism especially TAG accumulation. According to these findings, we propose that osmolarity should be carefully monitored during the industrial production of biodiesel.
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Affiliation(s)
- Feifei Xu
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, China
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, The Fourth Military Medical University, Xi’an, Shaanxi China
| | - Junmin Pan
- MOE Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong China
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Rapid and Positive Effect of Bicarbonate Addition on Growth and Photosynthetic Efficiency of the Green Microalgae Chlorella Sorokiniana (Chlorophyta, Trebouxiophyceae). APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10134515] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Bicarbonate ions are the primary source of inorganic carbon for autotrophic organisms living in aquatic environments. In the present study, we evaluated the short-term (hours) effects of sodium bicarbonate (NaHCO3) addition on the growth and photosynthetic efficiency of the green algae Chlorella sorokiniana (211/8k). Bicarbonate was added to nonaxenic cultures at concentrations of 1, 2, and 3 g L−1 leading to a significant increase in biomass especially at the highest salt concentration (3 g L−1) and also showing a bactericidal and bacteriostatic effect that helped to keep a reduced microbial load in the algal culture. Furthermore, bicarbonate stimulated the increase in cellular content of chlorophyll a, improving the photosynthetic performance of cells. Since microalgae of genus Chlorella spp. show great industrial potential for the production of biofuels, nutraceuticals, cosmetics, health, and dietary supplements and the use of bicarbonate as a source of inorganic carbon led to short-term responses in Chlorella sorokiniana, this method represents a valid alternative not only to the insufflation of carbon dioxide for the intensive cultures but also for the production of potentially bioactive compounds in a short period.
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Uritskiy G, Tisza MJ, Gelsinger DR, Munn A, Taylor J, DiRuggiero J. Cellular life from the three domains and viruses are transcriptionally active in a hypersaline desert community. Environ Microbiol 2020; 23:3401-3417. [DOI: 10.1111/1462-2920.15023] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 04/12/2020] [Indexed: 02/03/2023]
Affiliation(s)
- Gherman Uritskiy
- Department of Biology Johns Hopkins University Baltimore MD 21218 USA
| | - Michael J. Tisza
- Department of Biology Johns Hopkins University Baltimore MD 21218 USA
- Laboratory of Cellular Oncology NCI, NIH Bethesda MD 20892‐4263 USA
| | | | - Adam Munn
- Department of Biology Johns Hopkins University Baltimore MD 21218 USA
| | - James Taylor
- Department of Biology Johns Hopkins University Baltimore MD 21218 USA
- Department of Computer Science Johns Hopkins University Baltimore MD 21218 USA
| | - Jocelyne DiRuggiero
- Department of Biology Johns Hopkins University Baltimore MD 21218 USA
- Department of Earth and Planetary Sciences Johns Hopkins University Baltimore MD 21218 USA
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He Q, Toh JD, Ero R, Qiao Z, Kumar V, Serra A, Tan J, Sze SK, Gao YG. The unusual di-domain structure of Dunaliella salina glycerol-3-phosphate dehydrogenase enables direct conversion of dihydroxyacetone phosphate to glycerol. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 102:153-164. [PMID: 31762135 DOI: 10.1111/tpj.14619] [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: 06/18/2019] [Revised: 10/31/2019] [Accepted: 11/15/2019] [Indexed: 06/10/2023]
Abstract
Dunaliella has been extensively studied due to its intriguing adaptation to high salinity. Its di-domain glycerol-3-phosphate dehydrogenase (GPDH) isoform is likely to underlie the rapid production of the osmoprotectant glycerol. Here, we report the structure of the chimeric Dunaliella salina GPDH (DsGPDH) protein featuring a phosphoserine phosphatase-like domain fused to the canonical glycerol-3-phosphate (G3P) dehydrogenase domain. Biochemical assays confirm that DsGPDH can convert dihydroxyacetone phosphate (DHAP) directly to glycerol, whereas a separate phosphatase protein is required for this conversion process in most organisms. The structure of DsGPDH in complex with its substrate DHAP and co-factor nicotinamide adenine dinucleotide (NAD) allows the identification of the residues that form the active sites. Furthermore, the structure reveals an intriguing homotetramer form that likely contributes to the rapid biosynthesis of glycerol.
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Affiliation(s)
- Qinghua He
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization, College of Life Science and Technology, Southwest Minzu University, Chengdu, 610041, China
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore City, 637551, Singapore
| | - Joel Dewei Toh
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore City, 637551, Singapore
- Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), 61 Biopolis Drive, Singapore City, 138673, Singapore
| | - Rya Ero
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore City, 637551, Singapore
- NTU Institute of Structural Biology, Nanyang Technological University, 59 Nanyang Drive, Singapore City, 639798, Singapore
| | - Zhu Qiao
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore City, 637551, Singapore
- NTU Institute of Structural Biology, Nanyang Technological University, 59 Nanyang Drive, Singapore City, 639798, Singapore
| | - Veerendra Kumar
- Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), 61 Biopolis Drive, Singapore City, 138673, Singapore
| | - Aida Serra
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore City, 637551, Singapore
| | - Jackie Tan
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore City, 637551, Singapore
| | - Siu Kwan Sze
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore City, 637551, Singapore
| | - Yong-Gui Gao
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore City, 637551, Singapore
- Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), 61 Biopolis Drive, Singapore City, 138673, Singapore
- NTU Institute of Structural Biology, Nanyang Technological University, 59 Nanyang Drive, Singapore City, 639798, Singapore
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Zarkami R, Hesami H, Sadeghi Pasvisheh R. Assessment, monitoring and modelling of the abundance of Dunaliella salina Teod in the Meighan wetland, Iran using decision tree model. ENVIRONMENTAL MONITORING AND ASSESSMENT 2020; 192:172. [PMID: 32040638 DOI: 10.1007/s10661-020-8148-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Accepted: 02/05/2020] [Indexed: 06/10/2023]
Abstract
The microalga Dunaliella salina has been broadly studied for different purposes such as beta-carotene production, toxicity assessment and salinity tolerance, yet research on the habitat suitability of this alga has rarely been reported. The present research aims to apply a suitable monitoring and modelling methods (two critical steps in ecological researches) to predict the abundance of D. salina. The abundance of D. salina was predicted by decision tree model (J48 algorithm) in 10 different monitoring sites during 1-year study period (2016-2017) in the Meighan wetland, one of the valuable hypersaline wetlands in Iran. The abundance of alga (as output of model) together with various water quality and physical-habitat wetland characteristics (as inputs of model) were monthly and repeatedly monitored in two different depths (one from the surface layer and another one from the depth of maximum 50 cm) which in total resulted in 240 instances (120 instances for each depth). Based on trial and error, a sevenfold cross-validation resulted in the highest predictive performances of the model (CCI > 75% and Cohen's Kappa > 0.65). According to the model's prediction, the number of sunny hours might be one of the most important driving parameters to meet the habitat requirements of alga in the hypersaline wetland. Model also predicted that an increase in dissolved oxygen and sodium concentrations might increase the abundance of D. salina in the salt wetland. In contrast, an increase in total suspended solids concentration and monthly precipitation might lead to a decrease in the abundance of alga. Chi-square test of independence showed a significant difference between the abundance of the D. salina and spatio-temporal patterns in the wetland (Pearson chi-square statistic = 221.7, p = 0.001) so warm seasons (spring and summer) had more contribution to the sampling of the species than cold seasons (autumn and winter). The difference in the abundance of the species in different sampling sites can be attributed due to the various anthropogenic activities.
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Affiliation(s)
- Rahmat Zarkami
- Department of Environmental Science, Faculty of Natural Resources, University of Guilan, P.O. Box 1144, Sowmeh Sara, Iran.
| | - Hedieh Hesami
- Department of Environmental Science, Faculty of Natural Resources, University of Guilan, P.O. Box 1144, Sowmeh Sara, Iran
| | - Roghayeh Sadeghi Pasvisheh
- Department of Plants and Crops, Faculty of Bio-Science Engineering, Ghent University, Coupure Links, 653, 9000, Ghent, Belgium
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Carotenoids Overproduction in Dunaliella Sp.: Transcriptional Changes and New Insights through Lycopene β Cyclase Regulation. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9245389] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Dunaliella is a green microalga known for its ability to produce high levels of carotenoids under well-defined growing conditions. Molecular responses to the simultaneous effect of increasing salinity, light intensity and decrease of nitrogen availability were investigated in terms of their effect on different metabolic pathways (isoprenoids synthesis, glycolysis, carbohydrate use, etc.) by following the transcriptional regulation of enolase (ENO), 1-deoxy-D-xylulose 5-phosphate synthase (DXS), lycopene β-cyclase (LCYB), carotene globule protein (CGP), chloroplast-localized heat shock protein (HSP70), and chloroplast ribulose phosphate-3-epimerase (RPE) genes. The intracellular production of carotenoid was increased five times in stressed Dunaliella cells compared to those grown in an unstressed condition. At transcriptional levels, ENO implicated in glycolysis, and revealing about polysaccharides degradation, showed a two-stage response during the first 72 h. Genes directly involved in β-carotene accumulation, namely, CGP and LCYB, revealed the most important increase by about 54 and 10 folds, respectively. In silico sequence analysis, along with 3D modeling studies, were performed to identify possible posttranslational modifications of CGP and LCYB proteins. Our results described, for the first time, their probable regulation by sumoylation covalent attachment as well as the presence of expressed SUMO (small ubiquitin-related modifier) protein in Dunaliella sp.
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Jiang JY, Zhu S, Zhang Y, Sun X, Hu X, Huang H, Ren LJ. Integration of lipidomic and transcriptomic profiles reveals novel genes and regulatory mechanisms of Schizochytrium sp. in response to salt stress. BIORESOURCE TECHNOLOGY 2019; 294:122231. [PMID: 31606596 DOI: 10.1016/j.biortech.2019.122231] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 09/29/2019] [Accepted: 09/30/2019] [Indexed: 06/10/2023]
Abstract
In this study, the effects of salt stress on the physiological, lipidomic and transcriptomic profiles of halophilic microalga Schizochytrium sp. were investigated. In general, Schizochytrium sp. could survive under high osmotic fermentation medium containing 30 g/L NaCl, and showed a significant increase in C14:0 percentage in total fatty acids. In lipidomic analysis, C14:0 was specifically enriched in phosphatidylcholine (PC), and membrane phospholipids participated in the salt stress response mostly. Specially, one novel signal lipid N-acylphosphatidylethanolamine (NAPE) (18:0/20:3/14:0) was upregulated significantly. Transcriptomic analysis revealed glycerol-3-phosphate acyltransferase (GPAT) and phospholipase ABHD3 (PLABDH3) were involved in C14:0 metabolism and NAPE biosynthesis. Signalling pathways they mediated were activated as evident by high expression level of Myristoyl-CoA: protein N-myristoyltransferase (NMT) and NAPE-hydrolyzing PLD (NAPE-PLD). This study gives us an insight in specific responses to salt stress in Schizochytrium sp. and provides a considerable proportion of novel genes that could commendably be used for engineering modification.
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Affiliation(s)
- Jia-Yi Jiang
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China; School of Pharmaceutical Sciences, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China
| | - Siyu Zhu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China; School of Pharmaceutical Sciences, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China
| | - Yuting Zhang
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China; School of Pharmaceutical Sciences, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China
| | - Xiaoman Sun
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Wenyuan Road, Nanjing 210023, People's Republic of China; School of Pharmaceutical Sciences, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China
| | - Xuechao Hu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China; School of Pharmaceutical Sciences, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China; Jiangsu TianKai Biotechnology Co., Ltd. (Nanjing, P.R. China), No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China
| | - He Huang
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China; School of Pharmaceutical Sciences, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China; School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Wenyuan Road, Nanjing 210023, People's Republic of China
| | - Lu-Jing Ren
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China; School of Pharmaceutical Sciences, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China.
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Sampathkumar SJ, Gothandam KM. Sodium bicarbonate augmentation enhances lutein biosynthesis in green microalgae Chlorella pyrenoidosa. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2019. [DOI: 10.1016/j.bcab.2019.101406] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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41
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Wu Q, Lan Y, Cao X, Yao H, Qiao D, Xu H, Cao Y. Characterization and diverse evolution patterns of glycerol-3-phosphate dehydrogenase family genes in Dunaliella salina. Gene 2019; 710:161-169. [DOI: 10.1016/j.gene.2019.05.056] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 05/15/2019] [Accepted: 05/29/2019] [Indexed: 12/29/2022]
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42
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Gallego-Cartagena E, Castillo-Ramírez M, Martínez-Burgos W. Effect of stressful conditions on the carotenogenic activity of a Colombian strain of Dunaliella salina. Saudi J Biol Sci 2019; 26:1325-1330. [PMID: 31762591 PMCID: PMC6864209 DOI: 10.1016/j.sjbs.2019.07.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Revised: 07/18/2019] [Accepted: 07/23/2019] [Indexed: 10/26/2022] Open
Abstract
The objective was evaluate the carotenogenic activity of Dunaliella salina isolated from the artificial salt flats of municipality of Manaure (Department of La Guajira, Colombia). Two experimental testings were designed, in triplicate, to induce the reversibility of the cell tonality depending on the culture conditions. In the first test (A), to induce the reversibility from green to red tonality in D. salina cells, these were cultured in J/1 medium at a concentration of 4.0 M NaCl, 390 µmol m-2 s-1, 0.50 mM KNO3. In the second test (B), to induce the reversibility from red to green cell tonality, the cultures were maintained in J/1 medium 1 M NaCl, 190 µmol m-2 s-1, 5.0 mM KNO3 and pH 8.2. The population growth was evaluated by cell count and the pigment content was performed by spectrophotometric techniques. It was found that in both tests the culture conditions influenced the population growth and the pigments production of D. salina. There was a significant difference between the mean values of total carotenoids in the test A with 9.67 ± 0.19 μg/ml and second test with 1.54 ± 0.08 μg/ml at a significance level of p < 0.05. It was demonstrated that the culture conditions of test A induce the production of lipophilic antioxidants, among these carotenoids. The knowledge of the stressful conditions for the production of carotenoids from D. salina isolated from artificial saline of Manaure opens a field in implementation of this biotic resource for biotechnological purposes, production of new antibiotics, nutraceuticals and/or biofuels production.
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Affiliation(s)
- Euler Gallego-Cartagena
- Department of Civil and Environmental, Universidad de la Costa, Calle 58 #55-66, 080002 Barranquilla, Colombia
| | - Margarita Castillo-Ramírez
- Department of Civil and Environmental, Universidad de la Costa, Calle 58 #55-66, 080002 Barranquilla, Colombia
| | - Walter Martínez-Burgos
- Department Bioprocess Engineering and Biotechnology, Federal University of Paraná, Av. Celador Francisco H. dos Santos 210, Curitiba, Paraná, Brazil
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Besson A, Formosa-Dague C, Guiraud P. Flocculation-flotation harvesting mechanism of Dunaliella salina: From nanoscale interpretation to industrial optimization. WATER RESEARCH 2019; 155:352-361. [PMID: 30856519 DOI: 10.1016/j.watres.2019.02.043] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 02/17/2019] [Accepted: 02/19/2019] [Indexed: 06/09/2023]
Abstract
Dunaliella salina is a green microalgae species industrially exploited for its capacity to produce important amounts of carotenoid pigments. However in low nitrogen conditions in which they produce these pigments, their concentration is low, which results in harvesting difficulties and high costs. In this work, we propose a new solution to efficiently harvest D. salina at the pre-industrial scale, using flocculation/flotation harvesting induced by NaOH addition in the medium. We first show, using numerical simulations and nanoscale atomic force spectroscopy experiments, that sweeping mechanism in formed magnesium hydroxide precipitate is only responsible for D. salina flocculation in hypersaline culture medium upon NaOH addition. Based on this understanding of the flocculation mechanism, we then evaluate the influence of several parameters related to NaOH mixing and magnesium hydroxide precipitation and show that NaOH concentration, mixing, and salinity of the medium can be optimized to achieve high flocculation/flotation harvesting efficiencies in laboratory-scale experiments. We finally successfully scale-up the data obtained at lab-scale to a continuous pre-industrial flotation pilot, and achieve up to 80% of cell recovery. This interdisciplinary study thus provides original results, from the nano to the pre-industrial scale, which allow the successful development of an efficient large-scale D. salina harvesting process. We thus anticipate our results to be the starting point for further optimization and industrial use of this flocculation/flotation harvesting technique.
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Affiliation(s)
- Alexandre Besson
- LISBP, Université de Toulouse, INSA, INRA, CNRS, Toulouse, France
| | - Cécile Formosa-Dague
- LISBP, Université de Toulouse, INSA, INRA, CNRS, Toulouse, France; LAAS, Université de Toulouse, CNRS, Toulouse, France; FERMAT, Université de Toulouse, CNRS, INPT, INSA, UPS, Toulouse, France
| | - Pascal Guiraud
- LISBP, Université de Toulouse, INSA, INRA, CNRS, Toulouse, France; FERMAT, Université de Toulouse, CNRS, INPT, INSA, UPS, Toulouse, France.
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Two-Stage Cultivation of Dunaliella tertiolecta with Glycerol and Triethylamine for Lipid Accumulation: a Viable Way To Alleviate the Inhibitory Effect of Triethylamine on Biomass. Appl Environ Microbiol 2019; 85:AEM.02614-18. [PMID: 30552184 DOI: 10.1128/aem.02614-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 11/29/2018] [Indexed: 11/20/2022] Open
Abstract
Microalgae are promising alternatives for sustainable biodiesel production. Previously, it was found that 100 ppm triethylamine greatly enhanced lipid production and lipid content per cell of Dunaliella tertiolecta by 20% and 80%, respectively. However, triethylamine notably reduced biomass production and pigment contents. In this study, a two-stage cultivation with glycerol and triethylamine was attempted to improve cell biomass and lipid accumulation. At the first stage with 1.0 g/liter glycerol addition, D. tertiolecta cells reached the late log phase in a shorter time due to rapid cell growth, leading to the highest cell biomass (1.296 g/liter) for 16 days. However, the increased glycerol concentrations with glycerol addition decreased the lipid content. At the second-stage cultivation with 100 ppm triethylamine, the highest lipid concentration and lipid weight content were 383.60 mg/liter and 37.7% of dry cell weight (DCW), respectively, in the presence of 1.0 g/liter glycerol, which were 27.36% and 72.51% higher than those of the control group, respectively. Besides, the addition of glycerol alleviated the inhibitory effect of triethylamine on cell morphology, algal growth, and pigment accumulation in D. tertiolecta The results indicated that two-stage cultivation is a viable way to improve lipid yield in microalgae.IMPORTANCE Microalgae are promising alternatives for sustainable biodiesel production. Two-stage cultivation with glycerol and triethylamine enhanced the lipid productivity of Dunaliella tertiolecta, indicating that two-stage cultivation is an efficient strategy for biodiesel production from microalgae. It was found that glycerol significantly enhanced cell biomass of D. tertiolecta, and the presence of glycerol alleviated the inhibitory effect of triethylamine on algal growth. Glycerol, the major byproduct from biodiesel production, was used for the biomass accumulation of D. tertiolecta at the first stage of cultivation. Triethylamine, as a lipid inducer, was used for lipid accumulation at the second stage of cultivation. Two-stage cultivation with glycerol and triethylamine enhanced lipid productivity and alleviated the inhibitory effect of triethylamine on the algal growth of D. tertiolecta, which is an efficient strategy for lipid production from D. tertiolecta.
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Lee CJD, McMullan PE, O'Kane CJ, Stevenson A, Santos IC, Roy C, Ghosh W, Mancinelli RL, Mormile MR, McMullan G, Banciu HL, Fares MA, Benison KC, Oren A, Dyall-Smith ML, Hallsworth JE. NaCl-saturated brines are thermodynamically moderate, rather than extreme, microbial habitats. FEMS Microbiol Rev 2018; 42:672-693. [PMID: 29893835 DOI: 10.1093/femsre/fuy026] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 06/08/2018] [Indexed: 11/12/2022] Open
Abstract
NaCl-saturated brines such as saltern crystalliser ponds, inland salt lakes, deep-sea brines and liquids-of-deliquescence on halite are commonly regarded as a paradigm for the limit of life on Earth. There are, however, other habitats that are thermodynamically more extreme. Typically, NaCl-saturated environments contain all domains of life and perform complete biogeochemical cycling. Despite their reduced water activity, ∼0.755 at 5 M NaCl, some halophiles belonging to the Archaea and Bacteria exhibit optimum growth/metabolism in these brines. Furthermore, the recognised water-activity limit for microbial function, ∼0.585 for some strains of fungi, lies far below 0.755. Other biophysical constraints on the microbial biosphere (temperatures of >121°C; pH > 12; and high chaotropicity; e.g. ethanol at >18.9% w/v (24% v/v) and MgCl2 at >3.03 M) can prevent any cellular metabolism or ecosystem function. By contrast, NaCl-saturated environments contain biomass-dense, metabolically diverse, highly active and complex microbial ecosystems; and this underscores their moderate character. Here, we survey the evidence that NaCl-saturated brines are biologically permissive, fertile habitats that are thermodynamically mid-range rather than extreme. Indeed, were NaCl sufficiently soluble, some halophiles might grow at concentrations of up to 8 M. It may be that the finite solubility of NaCl has stabilised the genetic composition of halophile populations and limited the action of natural selection in driving halophile evolution towards greater xerophilicity. Further implications are considered for the origin(s) of life and other aspects of astrobiology.
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Affiliation(s)
- Callum J D Lee
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
| | - Phillip E McMullan
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
| | - Callum J O'Kane
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
| | - Andrew Stevenson
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
| | - Inês C Santos
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX 76019, USA
| | - Chayan Roy
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata, 700054, India
| | - Wriddhiman Ghosh
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata, 700054, India
| | - Rocco L Mancinelli
- BAER Institute, Mail Stop 239-4, NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - Melanie R Mormile
- Department of Biological Sciences, Missouri University of Science and Technology, Rolla, MO 65401, USA
| | - Geoffrey McMullan
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
| | - Horia L Banciu
- Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babes-Bolyai University, 400006 Cluj-Napoca, Romania
| | - Mario A Fares
- Department of Abiotic Stress, Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, Valencia 46022, Spain.,Institute for Integrative Systems Biology (I2SysBio), Consejo Superior de Investigaciones Científicas-Universitat de Valencia (CSIC-UV), Valencia, 46980, Spain.,Department of Genetics, Smurfit Institute of Genetics, University of Dublin, Trinity College, Dublin 2, Dublin, Ireland
| | - Kathleen C Benison
- Department of Geology and Geography, West Virginia University, Morgantown, WV 26506-6300, USA
| | - Aharon Oren
- Department of Plant & Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat-Ram, Jerusalem 9190401, Israel
| | - Mike L Dyall-Smith
- Faculty of Veterinary and Agricultural Science, The University of Melbourne, Parkville, VIC 3010, Australia
| | - John E Hallsworth
- Institute for Global Food Security, School of Biological Sciences, MBC, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland
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Xue Q, Wang R, Xu W, Wang J, Tan L. The stresses of allelochemicals isolated from culture solution of diatom Phaeodactylum tricornutum Bohlin on growth and physiology of two marine algae. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2018; 205:51-57. [PMID: 30321860 DOI: 10.1016/j.aquatox.2018.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Revised: 10/05/2018] [Accepted: 10/05/2018] [Indexed: 06/08/2023]
Abstract
The allelopathic effects of extracts isolated from the culture filtrate of diatom Phaeodactylum triconutum Bohlin on typical marine microalgae Prorocentrum donghaiense Lu and Dunaliella salina Teodoresco were investigated by determining different physiological and biochemical parameters, such as growth rate, membrane systems and esterase activity under controlled laboratory conditions. The growth of P. donghaiense was significantly inhibited immediately after exposure to the allelochemicals, while the algae density of D. salina was less sensitive. Chlorophyll-a content, membrane systems, as well as esterase activity were simultaneously investigated by flow cytometry with particular fluorescent markers and exhibited changeable sensitivities. The results demonstrated that the membrane systems of P. donghaiense were suppressed by the allelochemicals directly, causing loss of integrity and membrane penetration. Esterase activity was the most sensitive indicator as that of P. donghaiense cells significantly increased in short time and was inhibited subsequently. However, the membrane of D. salina remained intact still after exposure to the extracts and the esterase activity was only inhibited on last day during experiment period. Membrane potential and chlorophyll-a content of the two marine algae also showed somewhat different changes, as that of P. donghaiense cells were impaired after 5 day exposure to all volume conditions while these two characteristics of D. salina was only suppressed by exposure to high volume of the allelochemicals on day 6. The present results indicated that the inhibition of culture filtrate of P. triconutum on P. donghaiense was algicidal whereas the effect on D. salina appeared to be algistatic.
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Affiliation(s)
- Qiaona Xue
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China
| | - Rui Wang
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China
| | - Wenjing Xu
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China
| | - Jiangtao Wang
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
| | - Liju Tan
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China
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47
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Hong L, Liu JL, Midoun SZ, Miller PC. Transcriptome sequencing and annotation of the halophytic microalga Dunaliella salina. J Zhejiang Univ Sci B 2018; 18:833-844. [PMID: 28990374 DOI: 10.1631/jzus.b1700088] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The unicellular green alga Dunaliella salina is well adapted to salt stress and contains compounds (including β-carotene and vitamins) with potential commercial value. A large transcriptome database of D. salina during the adjustment, exponential and stationary growth phases was generated using a high throughput sequencing platform. We characterized the metabolic processes in D. salina with a focus on valuable metabolites, with the aim of manipulating D. salina to achieve greater economic value in large-scale production through a bioengineering strategy. Gene expression profiles under salt stress verified using quantitative polymerase chain reaction (qPCR) implied that salt can regulate the expression of key genes. This study generated a substantial fraction of D. salina transcriptional sequences for the entire growth cycle, providing a basis for the discovery of novel genes. This first full-scale transcriptome study of D. salina establishes a foundation for further comparative genomic studies.
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Affiliation(s)
- Ling Hong
- Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jun-Li Liu
- Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Samira Z Midoun
- Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Philip C Miller
- Systems Biology Research Group, Bioengineering Department, University of California, 9500 Gilman Dr. San Diego, La Jolla, CA 92093, USA
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48
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Gunde-Cimerman N, Plemenitaš A, Oren A. Strategies of adaptation of microorganisms of the three domains of life to high salt concentrations. FEMS Microbiol Rev 2018. [DOI: 10.1093/femsre/fuy009] [Citation(s) in RCA: 193] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Nina Gunde-Cimerman
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, SI-1000 Ljubljana, Slovenia
| | - Ana Plemenitaš
- Institute of Biochemistry, Medical Faculty, University of Ljubljana, Vrazov trg 1, SI-1000 Ljubljana, Slovenia
| | - Aharon Oren
- Department of Plant and Environmental Sciences, The Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 9190401, Israel
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49
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Kim YH, Goh TS, Lee CS, Oh SO, Kim JI, Jeung SH, Pak K. Prognostic value of microRNAs in osteosarcoma: A meta-analysis. Oncotarget 2018; 8:8726-8737. [PMID: 28060730 PMCID: PMC5352436 DOI: 10.18632/oncotarget.14429] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 12/01/2016] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Osteosarcoma is the most common primary bone malignancy. We meta-analyzed the prognostic value of altered miRNAs in patients with osteosarcoma. METHODS Sources from MEDLINE (from inception to August 2016) and EMBASE (from inception to August 2016) were searched. Studies of osteosarcoma with results of miRNA and studies that reported survival data were included and two authors performed the data extraction independently. Any discrepancies were resolved by a consensus. The outcome was overall survival and event-free survival assessed using hazard ratios (HRs). RESULTS After reviewing the full text of 65 articles, 25 studies including 2,278 patients were eligible in this study. The pooled HR for deaths was 1.40 (95% confidence interval [CI] 1.01-1.94, p=0.04) with random-effects model (χ2=113.08, p<0.00001, I2=79%) for patients of osteosarcoma with lower expression of miRNA. However, the pooled HR for events was not significant (HR 0.97, 0.63-1.48, p=0.87, χ2=72.65, p<0.00001, I2=79%). In pathway analysis of miRNAs, miRNA449a, 199-5p, 542-5p have common target genes. CONCLUSIONS Expression level of miRNA in patients of osteosarcoma is important as a prognostic factor.
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Affiliation(s)
- Yun Hak Kim
- BEER, Busan Society of Evidence-Based Medicine and Research, Busan, Republic of Korea.,Department of Anatomy, School of Medicine, Pusan National University, Yangsan, Gyeongnam, Republic of Korea
| | - Tae Sik Goh
- BEER, Busan Society of Evidence-Based Medicine and Research, Busan, Republic of Korea.,Department of Orthopaedic Surgery and Biomedical Research Institute, Pusan National University Hospital, Busan, Republic of Korea
| | - Chi-Seung Lee
- Biomedical Research Institute, Pusan National University Hospital and School of Medicine, Pusan National University, Busan, Republic of Korea
| | - Sae Ock Oh
- Department of Anatomy, School of Medicine, Pusan National University, Yangsan, Gyeongnam, Republic of Korea
| | - Jeung Il Kim
- Department of Orthopaedic Surgery and Biomedical Research Institute, Pusan National University Hospital, Busan, Republic of Korea
| | - Seung Hyeon Jeung
- Department of Orthopaedic Surgery and Biomedical Research Institute, Pusan National University Hospital, Busan, Republic of Korea
| | - Kyoungjune Pak
- BEER, Busan Society of Evidence-Based Medicine and Research, Busan, Republic of Korea.,Department of Nuclear Medicine and Biomedical Research Institute, Pusan National University Hospital, Busan, Republic of Korea
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50
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Harding T, Simpson AGB. Recent Advances in Halophilic Protozoa Research. J Eukaryot Microbiol 2018; 65:556-570. [PMID: 29266533 DOI: 10.1111/jeu.12495] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 11/14/2017] [Accepted: 12/08/2017] [Indexed: 11/30/2022]
Abstract
Most research on microorganisms adapted to hypersaline habitats has focused on Archaea and Bacteria, with microbial eukaryotes receiving much less attention. Over the past 15 yr, our knowledge of phagotrophic microbial eukaryotes, i.e. protozoa, from hypersaline habitats has greatly improved through combinations of microscopy, molecular phylogenetics, environmental sequencing, transcriptomics and growth experiments. High salinity waters from salterns, other landlocked water masses and deep hypersaline anoxic basins contain unique and diverse halophilic protozoan assemblages. These have the potential to exert substantial grazing pressure on prokaryotes and other eukaryotes. They represent many separate evolutionary lineages; species of Heterolobosea, Bicosoecida, and Ciliophora have been most intensively characterized, with several proven to be extreme (or borderline extreme) halophiles. Transcriptomic examinations of the bicosoecid Halocafeteria (and the heteroloboseid Pharyngomonas) indicate that high-salt adaptation is associated with a subtle shift in protein amino acid composition, and involves the differential expression of genes participating in ion homeostasis, signal transduction, stress management, and lipid remodeling. Instances of gene duplication and lateral transfer possibly conferring adaptation have been documented. Indirect evidence suggests that these protozoa use "salt-out" osmoadaptive strategies.
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Affiliation(s)
- Tommy Harding
- Department of Biochemistry and Molecular Biology, Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, NS, B3H 4R2, Canada
| | - Alastair G B Simpson
- Department of Biology, and Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, NS, B3H 4R2, Canada
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