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Ruan Z, Lu M, Lin H, Chen S, Li P, Chen W, Xu H, Qiu D. Different photosynthetic responses of haploid and diploid Emiliania huxleyi (Prymnesiophyceae) to high light and ultraviolet radiation. BIORESOUR BIOPROCESS 2023; 10:40. [PMID: 38647570 PMCID: PMC10991182 DOI: 10.1186/s40643-023-00660-5] [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: 02/23/2023] [Accepted: 06/15/2023] [Indexed: 04/25/2024] Open
Abstract
Solar radiation varies quantitatively and qualitatively while penetrating through the seawater column and thus is one of the most important environmental factors shaping the vertical distribution pattern of phytoplankton. The haploid and diploid life-cycle phases of coccolithophores might have different vertical distribution preferences. Therefore, the two phases respond differently to high solar photosynthetically active radiation (PAR, 400-700 nm) and ultraviolet radiation (UVR, 280-400 nm). To test this, the haploid and diploid Emiliania huxleyi were exposed to oversaturating irradiance. In the presence of PAR alone, the effective quantum yield was reduced by 10% more due to the higher damage rate of photosystem II in haploid cells than in diploid cells. The addition of UVR resulted in further inhibition of the quantum yield for both haploid and diploid cells in the first 25 min, partly because of the increased damage of photosystem II. Intriguingly, this UVR-induced inhibition of the haploid cells completely recovered half an hour later. This recovery was confirmed by the comparable maximum quantum yields, maximum relative electron transport rates and yields of the haploid cells treated with PAR and PAR + UVR. Our data indicated that photosynthesis of the haploid phase was more sensitive to high visible light than the diploid phase but resistant to UVR-induced inhibition, reflecting the ecological niches to which this species adapts.
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Affiliation(s)
- Zuoxi Ruan
- STU-UNIVPM Joint Algal Research Center, Guangdong Provincial Key Laboratory of Marine Biotechnology, Marine Biology Institute, Shantou University, Shantou, 515063, Guangdong, China
| | - Meifang Lu
- STU-UNIVPM Joint Algal Research Center, Guangdong Provincial Key Laboratory of Marine Biotechnology, Marine Biology Institute, Shantou University, Shantou, 515063, Guangdong, China
| | - Hongmin Lin
- College of Pharmacy and Life Sciences, Jiujiang University, Jiujiang, 332005, Jiangxi, China
| | - Shanwen Chen
- STU-UNIVPM Joint Algal Research Center, Guangdong Provincial Key Laboratory of Marine Biotechnology, Marine Biology Institute, Shantou University, Shantou, 515063, Guangdong, China
| | - Ping Li
- STU-UNIVPM Joint Algal Research Center, Guangdong Provincial Key Laboratory of Marine Biotechnology, Marine Biology Institute, Shantou University, Shantou, 515063, Guangdong, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, Guangdong, China
| | - Weizhou Chen
- STU-UNIVPM Joint Algal Research Center, Guangdong Provincial Key Laboratory of Marine Biotechnology, Marine Biology Institute, Shantou University, Shantou, 515063, Guangdong, China
| | - Huijuan Xu
- CAS Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou, 510640, Guangdong, China.
| | - Dajun Qiu
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, Guangdong, China.
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Fakhreeva AV, Nosov VV, Voloshin AI, Dokichev VA. Polysaccharides as Effective and Environmentally Friendly Inhibitors of Scale Deposition from Aqueous Solutions in Technological Processes. Polymers (Basel) 2023; 15:polym15061478. [PMID: 36987258 PMCID: PMC10059850 DOI: 10.3390/polym15061478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/06/2023] [Accepted: 03/10/2023] [Indexed: 03/19/2023] Open
Abstract
In this paper, we consider natural and modified polysaccharides for use as active ingredients in scale deposition inhibitors to prevent the formation of scale in oil production equipment, heat exchange equipment, and water supply systems. Modified and functionalized polysaccharides with a strong ability to inhibit the formation of deposits of typical scale, such as carbonates and sulfates of alkaline earth elements found in technological processes, are described. This review discusses the mechanisms of the inhibition of crystallization using polysaccharides, and the various methodological aspects of evaluating their effectiveness are considered. This review also provides information on the technological application of scale deposition inhibitors based on polysaccharides. Special attention is paid to the environmental aspect of the use of polysaccharides in industry as scale deposition inhibitors.
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Affiliation(s)
- Alsu Venerovna Fakhreeva
- Ufa Institute of Chemistry, Ufa Federal Research Center, Russian Academy of Sciences, Ufa 450054, Russia
| | | | - Alexander Iosifovich Voloshin
- Ufa Institute of Chemistry, Ufa Federal Research Center, Russian Academy of Sciences, Ufa 450054, Russia
- RN–BashNIPIneft LLC, Ufa 450103, Russia
- Correspondence: ; Tel.: +7-917-470-6695
| | - Vladimir Anatolyevich Dokichev
- Ufa Institute of Chemistry, Ufa Federal Research Center, Russian Academy of Sciences, Ufa 450054, Russia
- RN–BashNIPIneft LLC, Ufa 450103, Russia
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Yun J, Jeong Y, Nam O, Yeo KB, Jo YK, Heo HR, Kim CS, Joo KI, Pack SP, Jin E, Cha HJ. Bone Graft Biomineral Complex Coderived from Marine Biocalcification and Biosilicification. ACS APPLIED BIO MATERIALS 2021; 4:6046-6055. [DOI: 10.1021/acsabm.1c00346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jinyoung Yun
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Yeonsu Jeong
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Onyou Nam
- Department of Life Science, Hanyang University, Seoul 04763, Republic of Korea
| | - Ki Baek Yeo
- Department of Biotechnology and Bioinformatics, Korea University, Sejong 30019, Republic of Korea
| | - Yun Kee Jo
- Department of Biomedical Convergence Science and Technology, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Hye Ryoung Heo
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Chang Sup Kim
- School of Chemistry and Biochemistry, Yeungnam University, Gyeongsan 38541, Republic of Korea
| | - Kye Il Joo
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Seung Pil Pack
- Department of Biotechnology and Bioinformatics, Korea University, Sejong 30019, Republic of Korea
| | - EonSeon Jin
- Department of Life Science, Hanyang University, Seoul 04763, Republic of Korea
| | - Hyung Joon Cha
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
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Coccolith crystals: Pure calcite or organic-mineral composite structures? Acta Biomater 2021; 125:83-89. [PMID: 33631395 DOI: 10.1016/j.actbio.2021.02.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 11/20/2022]
Abstract
The localization of organic material within biominerals is central to developing biomineral formation mechanisms. Coccoliths, morphologically sophisticated calcite platelets of intracellularly calcifying coccolithophores, are not only eco-physiologically important, but also influence biogeochemical cycles through mass production. Despite their importance and over a century of research, the formation mechanism of coccoliths is still poorly understood. Crucial unsolved questions include the localization of organic material within coccoliths. In extracellular calcifiers the discovery of an organics-containing nano-structure within seemingly single crystals has led to the formulation of a two-step crystallization mechanism. Coccoliths are traditionally thought of as being formed by a different mechanism, but it is unclear whether coccolith crystals possess a nano-structure. Here we review the evidence for and against such a nano-structure. Current SXPD analyses suggest a nano-structure of some kind, while imaging methods (SEM, TEM, AFM) provide evidence against it. We suggest directions for future research which should help solve this puzzle. STATEMENT OF SIGNIFICANCE: Coccolithophores, unicellular calcifying algae, are important primary producers and contribute significantly to pelagic calcium carbonate export. Their calcite platelets, the coccoliths, are amongst the most sophisticated biomineral structures. Understanding the crystallization mechanism of coccolith crystals is not only central to coccolithophore cell biology but also lies at the heart of biomineralization research more generally. The crystallization mechanism of coccoliths has remained largely elusive, not least because it is still an open question whether the micron sized coccolith crystals are pure calcite, or contain organic material. Here we review the state of the art and suggest a way to solve this central problem.
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Nissimov JI, Vandzura R, Johns CT, Natale F, Haramaty L, Bidle KD. Dynamics of transparent exopolymer particle production and aggregation during viral infection of the coccolithophore, Emiliania huxleyi. Environ Microbiol 2018; 20:2880-2897. [PMID: 29921002 DOI: 10.1111/1462-2920.14261] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 04/25/2018] [Accepted: 04/26/2018] [Indexed: 11/30/2022]
Abstract
Emiliania huxleyi produces calcium carbonate (CaCO3 ) coccoliths and transparent exopolymer particles (TEP), sticky, acidic carbohydrates that facilitate aggregation. E. huxleyi's extensive oceanic blooms are often terminated by coccolithoviruses (EhVs) with the transport of cellular debris and associated particulate organic carbon (POC) to depth being facilitated by TEP-bound 'marine snow' aggregates. The dynamics of TEP production and particle aggregation in response to EhV infection are poorly understood. Using flow cytometry, spectrophotometry and FlowCam visualization of alcian blue (AB)-stained aggregates, we assessed TEP production and the size spectrum of aggregates for E. huxleyi possessing different degrees of calcification and cellular CaCO3 :POC mass ratios, when challenged with two EhVs (EhV207 and EhV99B1). FlowCam imaging also qualitatively assessed the relative amount of AB-stainable TEP (i.e., blue:red ratio of each particle). We show significant increases in TEP during early phase EhV207-infection (∼ 24 h) of calcifying strains and a shift towards large aggregates following EhV99B1-infection. We also observed the formation of large aggregates with low blue:red ratios, suggesting that other exopolymer substances contribute towards aggregation. Our findings show the potential for virus infection and the associated response of their hosts to impact carbon flux dynamics and provide incentive to explore these dynamics in natural populations.
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Affiliation(s)
- Jozef I Nissimov
- Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road New Brunswick, NJ, USA
| | - Rebecca Vandzura
- Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road New Brunswick, NJ, USA
| | - Christopher T Johns
- Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road New Brunswick, NJ, USA
| | - Frank Natale
- Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road New Brunswick, NJ, USA
| | - Liti Haramaty
- Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road New Brunswick, NJ, USA
| | - Kay D Bidle
- Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road New Brunswick, NJ, USA
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Taylor AR, Brownlee C, Wheeler G. Coccolithophore Cell Biology: Chalking Up Progress. ANNUAL REVIEW OF MARINE SCIENCE 2017; 9:283-310. [PMID: 27814031 DOI: 10.1146/annurev-marine-122414-034032] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Coccolithophores occupy a special position within the marine phytoplankton because of their production of intricate calcite scales, or coccoliths. Coccolithophores are major contributors to global ocean calcification and long-term carbon fluxes. The intracellular production of coccoliths requires modifications to cellular ultrastructure and metabolism that are surveyed here. In addition to calcification, which appears to have evolved with a diverse range of functions, several other remarkable features that likely underpin the ecological and evolutionary success of coccolithophores have recently been uncovered. These include complex and varied life cycle strategies related to abiotic and biotic interactions as well as a range of novel metabolic pathways and nutritional strategies. Together with knowledge of coccolithophore genetic and physiological variability, these findings are beginning to shed new light on species diversity, distribution, and ecological adaptation. Further advances in genetics and functional characterization at the cellular level will likely to lead to a rapid increase in this understanding.
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Affiliation(s)
- Alison R Taylor
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, North Carolina 28403;
| | - Colin Brownlee
- Marine Biological Association, Plymouth PL1 2PB, United Kingdom; ,
- School of Ocean and Earth Science, National Oceanography Centre, University of Southampton, Southampton SO14 3ZH, United Kingdom
| | - Glen Wheeler
- Marine Biological Association, Plymouth PL1 2PB, United Kingdom; ,
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The uronic acid content of coccolith-associated polysaccharides provides insight into coccolithogenesis and past climate. Nat Commun 2016; 7:13144. [PMID: 27782214 PMCID: PMC5095175 DOI: 10.1038/ncomms13144] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 09/07/2016] [Indexed: 11/08/2022] Open
Abstract
Unicellular phytoplanktonic algae (coccolithophores) are among the most prolific producers of calcium carbonate on the planet, with a production of ∼1026 coccoliths per year. During their lith formation, coccolithophores mainly employ coccolith-associated polysaccharides (CAPs) for the regulation of crystal nucleation and growth. These macromolecules interact with the intracellular calcifying compartment (coccolith vesicle) through the charged carboxyl groups of their uronic acid residues. Here we report the isolation of CAPs from modern day coccolithophores and their prehistoric predecessors and we demonstrate that their uronic acid content (UAC) offers a species-specific signature. We also show that there is a correlation between the UAC of CAPs and the internal saturation state of the coccolith vesicle that, for most geologically abundant species, is inextricably linked to carbon availability. These findings suggest that the UAC of CAPs reports on the adaptation of coccolithogenesis to environmental changes and can be used for the estimation of past CO2 concentrations. Coccolith-associated polysaccharides (CAPs) are central for the biomineralization of marine algae. Here, Lee et al. show that CAPs can be isolated from extant and fossil samples and that their uronic acid content can be used as a palaeoclimate proxy.
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Light intensity modulation by coccoliths of Emiliania huxleyi as a micro-photo-regulator. Sci Rep 2015; 5:13577. [PMID: 26323524 PMCID: PMC4555034 DOI: 10.1038/srep13577] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Accepted: 07/31/2015] [Indexed: 11/25/2022] Open
Abstract
In this study, we present experimental evidence showing that coccoliths have light-scattering anisotropy that contributes to a possible control of solar light exposure in the ocean. Changing the angle between the incident light and an applied magnetic field causes differences in the light-scattering intensities of a suspension of coccoliths isolated from Emiliania huxleyi. The magnetic field effect is induced by the diamagnetic torque force directing the coccolith radial plane perpendicular to the applied magnetic fields at 400 to 500 mT. The developed technique reveals the light-scattering anisotropies in the 3-μm-diameter floating coccoliths by orienting themselves in response to the magnetic fields. The detached coccolith scatters radially the light incident to its radial plane. The experimental results on magnetically oriented coccoliths show that an individual coccolith has a specific direction of light scattering, although the possible physiological effect of the coccolith remains for further study, focusing on the light-scattering anisotropies of coccoliths on living cells.
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Tsuji Y, Yamazaki M, Suzuki I, Shiraiwa Y. Quantitative Analysis of Carbon Flow into Photosynthetic Products Functioning as Carbon Storage in the Marine Coccolithophore, Emiliania huxleyi. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2015; 17:428-440. [PMID: 25874681 PMCID: PMC4486895 DOI: 10.1007/s10126-015-9632-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Accepted: 01/31/2015] [Indexed: 05/31/2023]
Abstract
The bloom-forming coccolithophore Emiliania huxleyi (Haptophyta) is a dominant marine phytoplankton, cells of which are covered with calcareous plates (coccoliths). E. huxleyi produces unique lipids of C37-C40 long-chain ketones (alkenones) with two to four trans-unsaturated bonds, β-glucan (but not α-glucan) and acid polysaccharide (AP) associated with the morphogenesis of CaCO3 crystals in coccoliths. Despite such unique features, there is no detailed information on the patterns of carbon allocation into these compounds. Therefore, we performed quantitative estimation of carbon flow into various macromolecular products by conducting (14)C-radiotracer experiments using NaH(14)CO3 as a substrate. Photosynthetic (14)C incorporation into low molecular-mass compounds (LMC), extracellular AP, alkenones, and total lipids except alkenones was estimated to be 35, 13, 17, and 25 % of total (14)C fixation in logarithmic growth phase cells and 33, 19, 18, and 18 % in stationary growth phase cells, respectively. However, less than 1 % of (14)C was incorporated into β-glucan in both cells. (14)C-mannitol occupied ca. 5 % of total fixed (14)C as the most dominant LMC product. Levels of all (14)C compounds decreased in the dark. Therefore, alkenones and LMC (including mannitol), but not β-glucan, function in carbon/energy storage in E. huxleyi, irrespective of the growth phase. Compared with other algae, the low carbon flux into β-glucan is a unique feature of carbon metabolism in E. huxelyi.
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Affiliation(s)
- Yoshinori Tsuji
- />Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577 Japan
- />Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Tsukuba, 305-8572 Japan
| | - Masatoshi Yamazaki
- />Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, 305-8572 Japan
| | - Iwane Suzuki
- />Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577 Japan
- />Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Tsukuba, 305-8572 Japan
| | - Yoshihiro Shiraiwa
- />Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577 Japan
- />Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Tsukuba, 305-8572 Japan
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Fukuda SY, Suzuki Y, Shiraiwa Y. Difference in physiological responses of growth, photosynthesis and calcification of the coccolithophore Emiliania huxleyi to acidification by acid and CO2 enrichment. PHOTOSYNTHESIS RESEARCH 2014; 121:299-309. [PMID: 24500605 PMCID: PMC4077257 DOI: 10.1007/s11120-014-9976-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 01/21/2014] [Indexed: 05/15/2023]
Abstract
Ocean acidification, one of the great global environmental issues at present, is expected to result in serious damage on marine calcareous organisms such as corals and calcifying algae, which potentially release huge amounts of CO2 from the ocean to the atmosphere. The coccolithophore, Emiliania huxleyi (Haptophyceae), which frequently produces blooms, has greatly contributed to the biological CO2 pump. This study was aimed at analyzing effects of how E. huxleyi responds to acidification. Acidification was performed by two methods, namely by just adding HCl under bubbling ordinary air at 8.2-8.4, 7.6-7.8 and 7.1-7.3 (acidification by HCl) and by bubbling with ordinary air or with increased CO2 concentration such as 406, 816 and 1,192 ppm that maintained pH of the medium at 8.0-8.3, 7.6-7.9 and 7.5-7.7 (acidification by CO2 enrichment). As a result, cell growth and cellular calcification of E. huxleyi were strongly damaged by acidification by HCl, but not by acidification by CO2 enrichment. The activities of photosystems such as F v/F m and ϕPSII were not affected by any acidification conditions while photosynthetic O2 evolution was slightly stimulated. A (45)Ca-radiotracer experiment revealed that Ca(2+)-uptake was strongly suppressed by acidification with HCl. This suppression recovered after increasing the dissolved inorganic carbon (DIC) concentration and further stimulated by an additional increase in DIC concentration. The production of storage and coccolith polysaccharides was increased by acidification by HCl and also highly stimulated by acidification with CO2 enrichment. The present study clearly showed that the coccolithophore, E. huxleyi, has an ability to respond positively to acidification with CO2 enrichment, but not just acidification.
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Affiliation(s)
- Shin-ya Fukuda
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Japan
| | - Yurina Suzuki
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Japan
| | - Yoshihiro Shiraiwa
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Japan
- CREST, JST, 1-1-1 Tennodai, Tsukuba, Japan
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Fulton JM, Fredricks HF, Bidle KD, Vardi A, Kendrick BJ, DiTullio GR, Van Mooy BAS. Novel molecular determinants of viral susceptibility and resistance in the lipidome ofEmiliania huxleyi. Environ Microbiol 2014; 16:1137-49. [DOI: 10.1111/1462-2920.12358] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 12/05/2013] [Indexed: 12/20/2022]
Affiliation(s)
- James M. Fulton
- Department of Marine Chemistry and Geochemistry; Woods Hole Oceanographic Institution; Woods Hole MA USA
| | - Helen F. Fredricks
- Department of Marine Chemistry and Geochemistry; Woods Hole Oceanographic Institution; Woods Hole MA USA
| | - Kay D. Bidle
- Environmental Biophysics and Molecular Ecology Laboratory; Institute of Marine and Coastal Sciences; Rutgers University; New Brunswick NJ USA
| | - Assaf Vardi
- Department of Plant Sciences; Weizmann Institute of Science; Rehovot Israel
| | | | | | - Benjamin A. S. Van Mooy
- Department of Marine Chemistry and Geochemistry; Woods Hole Oceanographic Institution; Woods Hole MA USA
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Van Oostende N, Moerdijk-Poortvliet TCW, Boschker HTS, Vyverman W, Sabbe K. Release of dissolved carbohydrates by Emiliania huxleyi and formation of transparent exopolymer particles depend on algal life cycle and bacterial activity. Environ Microbiol 2012; 15:1514-31. [PMID: 22985062 DOI: 10.1111/j.1462-2920.2012.02873.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 07/27/2012] [Accepted: 08/04/2012] [Indexed: 11/30/2022]
Abstract
The coccolithophore Emiliania huxleyi plays a pivotal role in the marine carbon cycle. However, we have only limited understanding of how its life cycle and bacterial interactions affect the production and composition of dissolved extracellular organic carbon and its transfer to the particulate pool. We traced the fate of photosynthetically fixed carbon during phosphate-limited stationary growth of non-axenic, calcifying E. huxleyi batch cultures, and more specifically the transfer of this carbon to bacteria and to dissolved high molecular weight neutral aldoses (HMW NAld) and extracellular particulate carbon. We then compared the dynamics of dissolved carbohydrates and transparent exopolymer particles (TEP) between cultures of non-axenic and axenic diploid E. huxleyi. In addition, we present the first data on extracellular organic carbon in (non-axenic) haploid E. huxleyi cultures. Bacteria enhanced the accumulation of dissolved polysaccharides and altered the composition of dissolved HMW NAld, while they also stimulated the formation of TEP containing high densities of charged polysaccharides in diploid E. huxleyi cultures. In haploid E. huxleyi cultures we found a more pronounced accumulation of dissolved carbohydrates, which had a different NAld composition than the diploid cultures. TEP formation was significantly lower than in the diploid cultures, despite the presence of bacteria. In diploid E. huxleyi cultures, we measured a high level of extracellular release of organic carbon (34-76%), retrieved mainly in the particulate pool instead of the dissolved pool. Enhanced formation of sticky TEP due to bacteria-alga interactions, in concert with the production of coccoliths, suggests that especially diploid E. huxleyi blooms increase the efficiency of export production in the ocean during dissolved phosphate-limited conditions.
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Affiliation(s)
- Nicolas Van Oostende
- Research Group Protistology and Aquatic Ecology, Department of Biology, Ghent University, Krijgslaan 281 - S8, B-9000, Gent, Belgium.
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Xu K, Gao K. Reduced calcification decreases photoprotective capability in the coccolithophorid Emiliania huxleyi. PLANT & CELL PHYSIOLOGY 2012; 53:1267-1274. [PMID: 22555817 DOI: 10.1093/pcp/pcs066] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Intracellular calcification of coccolithophores generates CO₂ and consumes additional energy for acquisition of calcium and bicarbonate ions; therefore, it may correlate with photoprotective processes by influencing the energetics. To address this hypothesis, a calcifying Emiliania huxleyi strain (CS-369) was grown semi-continuously at reduced (0.1 mM, LCa) and ambient Ca²⁺ concentrations (10 mM, HCa) for 150 d (>200 generations). The HCa-grown cells had higher photosynthetic and calcification rates and higher contents of Chl a and carotenoids compared with the naked (bearing no coccoliths) LCa-grown cells. When exposed to stressfull levels of photosynthetically active radiation (PAR), LCa-grown cells displayed lower photochemical yield and less efficient non-photochemical quenching (NPQ). When the LCa- or HCa-grown cells were inversely shifted to their counterpart medium, LCa to HCa transfer increased photosynthetic carbon fixation (P), calcification rate (C), the C/P ratio, NPQ and pigment contents, whereas those shifted from HCa to LCa exhibited the opposite effects. Increased NPQ, carotenoids and quantum yield were clearly linked with increased or sustained calcification in E. huxleyi. The calcification must have played a role in dissipating excessive energy or as an additional drainage of electrons absorbed by the photosynthetic antennae. This phenomenon was further supported by testing two non-calcifying strains, which showed insignificant changes in photosynthetic carbon fixation and NPQ when transferred to LCa conditions.
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Affiliation(s)
- Kai Xu
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005, PR China
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Kayano K, Saruwatari K, Kogure T, Shiraiwa Y. Effect of coccolith polysaccharides isolated from the coccolithophorid, Emiliania huxleyi, on calcite crystal formation in in vitro CaCO3 crystallization. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2011; 13:83-92. [PMID: 20336339 DOI: 10.1007/s10126-010-9272-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Accepted: 01/06/2010] [Indexed: 05/29/2023]
Abstract
Marine coccolithophorids (Haptophyceae) produce calcified scales "coccoliths" which are composed of CaCO(3) and coccolith polysaccharides (CP) in the coccolith vesicles. CP was previously reported to be composed of uronic acids and sulfated residues, etc. attached to the polymannose main chain. Although anionic polymers are generally known to play key roles in biomineralization process, there is no experimental data how CP contributes to calcite crystal formation in the coccolithophorids. CP used was isolated from the most abundant coccolithophorid, Emiliania huxleyi. CaCO(3) crystallization experiment was performed on agar template layered onto a plastic plate that was dipped in the CaCO(3) crystallization solution. The typical rhombohedral calcite crystals were formed in the absence of CP. CaCO(3) crystals formed on the naked plastic plate were obviously changed to stick-like shapes when CP was present in the solution. EBSD analysis proved that the crystal is calcite of which c-axis was elongated. CP in the solution stimulated the formation of tabular crystals with flat edge in the agarose gel. SEM and FIB-TEM observations showed that the calcite crystals were formed in the gel. The formation of crystals without flat edge was stimulated when CP was preliminarily added in the gel. These observations suggest that CP has two functions: namely, one is to elongate the calcite crystal along c-axis and another is to induce tabular calcite crystal formation in the agarose gel. Thus, CP may function for the formation of highly elaborate species-specific structures of coccoliths in coccolithophorids.
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Affiliation(s)
- Keisuke Kayano
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8572, Japan
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