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Wang X, Wu X, Sun J. Seasonal dynamics and key drivers of phytoplankton community structure in the Eastern Indian Ocean. MARINE POLLUTION BULLETIN 2025; 212:117548. [PMID: 39813879 DOI: 10.1016/j.marpolbul.2025.117548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2024] [Revised: 01/08/2025] [Accepted: 01/08/2025] [Indexed: 01/18/2025]
Abstract
To fully understand variation in phytoplankton community structure in the Eastern Indian Ocean (EIO), two research cruises were carried out during September-November 2020, and March-May 2021. The phytoplankton community in the EIO was mainly composed of cyanobacteria and diatoms in 2020, cyanobacteria in 2021. Trichodesmium thiebaultii was the dominant specie in both years. The phytoplankton community of the EIO was classified into two provinces based on cluster. The RDA results indicated that in 2020, DIP was the predominant factor influencing phytoplankton abundance, but DIN as the main factor affecting phytoplankton abundance in 2021. Meanwhile, the SEM demonstrated that temperature and salinity indirectly influenced phytoplankton abundance by affecting nutrient concentrations (DIN and DIP) and vertical stratification index (VSI). Changes in nutrient concentrations had a greater impact on phytoplankton communities, especially diatoms and dinoflagellates. The phytoplankton community shifted from cyanobacteria to diatoms when VSI decrease, the composition of the community was also more complex. The composition and assembly mechanisms of phytoplankton communities indicated that seasonal seawater mixing enhanced growth and interspecific interactions, thus increasing network complexity and significantly influencing community structure.
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Affiliation(s)
- Xingzhou Wang
- College of Marine Science and Technology, China University of Geosciences (Wuhan), Wuhan 430074, China; Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin 300457, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Wuhan), Wuhan 430074, China
| | - Xi Wu
- College of Marine Science and Technology, China University of Geosciences (Wuhan), Wuhan 430074, China; Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Jun Sun
- College of Marine Science and Technology, China University of Geosciences (Wuhan), Wuhan 430074, China; Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin 300457, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Wuhan), Wuhan 430074, China.
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2
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Wang C, Liu F. Influence of oceanic mesoscale eddies on the deep chlorophyll maxima. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:170510. [PMID: 38286277 DOI: 10.1016/j.scitotenv.2024.170510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 01/14/2024] [Accepted: 01/26/2024] [Indexed: 01/31/2024]
Abstract
The deployment of the biogeochemical Argo network significantly enhances our understanding of the ecological effects of mesoscale eddies at different ocean depths. In this study, satellite data and more than one hundred thousand biogeochemical Argo float profiles were used to analyze the responses of the deep chlorophyll maximum (DCM) to mesoscale eddies. The DCM profiles were categorized into two types: DAM (adaptation maximum) and DBM (biomass maximum), based on their adaptation to light and maximum biomass characteristics. The variabilities in the DCM profiles in terms of latitude, seasonality, and their response to mesoscale eddies were subsequently investigated on a global scale. Our analysis demonstrates that light and nutrient availability explain a significant portion of the variability in the phytoplankton distribution across different regions and seasons. Statistical analysis reveals that cyclonic (anticyclonic) eddies enhance (weaken) the intensity of the DCM. The magnitude of this enhancement or weakening exhibits regional differences. Specifically, high-latitude regions are more influenced by eddies in terms of light-adapted DCM intensity, while in mid-latitude regions, eddies exhibit a stronger effect on the maximum biomass-driven DCM intensity. Moreover, our findings suggest that eddies in the North Atlantic Subtropical Gyre contribute to a downward shift in the euphotic zone depth, leading to an increased DCM depth and strengthened DCM intensity. However, in the equatorial region, eddies impact the DCM depth by influencing the nitracline (a layer in a body of water in which the nitrate concentration changes rapidly with depth). Similar patterns are frequently observed in different regions at the same latitude, providing a foundation for further detailed investigations of the DCM in specific areas.
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Affiliation(s)
- Changjie Wang
- School of Marine Sciences, Sun Yat-sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China
| | - Fenfen Liu
- School of Marine Sciences, Sun Yat-sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China; Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-sen University, Zhuhai 519082, China.
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3
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Wang Y, Zhao F, He X, Wang W, Chang L, Kang J. Latitudinal and meridional patterns of picophytoplankton variability are contrastingly associated with Ekman pumping and the warm pool in the tropical western Pacific. Ecol Evol 2023; 13:e10589. [PMID: 37869438 PMCID: PMC10587655 DOI: 10.1002/ece3.10589] [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: 06/18/2023] [Revised: 09/15/2023] [Accepted: 09/22/2023] [Indexed: 10/24/2023] Open
Abstract
Marine picophytoplankton plays a major role in marine cycling and energy conversion, and its effects on the carbon cycle and global climate change have been well documented. In this study, we investigated the response of picophytoplankton across a broad range of physicochemical conditions in two distinct regions of the tropical western Pacific. Our analysis considered the abundance, carbon biomass, size fraction, distribution, and regulatory factors of the picophytoplankton community, which included the cyanobacteria Prochlorococcus and Synechococcus, and small eukaryotic phytoplankton (picoeukaryotes). The first region was a latitudinal transect along the equator (142-163° E, 0° N), characterized by stratified oligotrophic conditions. The second region was a meridional transect (143° E, 0-22° N) known for its high-nutrient and low-chlorophyll (HNLC) conditions. Results showed that picophytoplankton contributed >80% of the chlorophyll a (Chl a), and was mainly distributed above 100 m. Prochlorococcus was the dominant organism in terms of cell abundance and estimated carbon biomass in both latitudinal and meridional transects, followed by Synechococcus and picoeukaryotes. In the warm pool, Prochlorococcus was primarily distributed below the isothermal layer, with the maximum subsurface abundance forming below it. The maximum Synechococcus abundance was restricted to the west-warm pool, due to the high temperature, and the second-highest Synechococcus abundance was associated with frontal interaction between the east-warm pool and the westward advance of Middle East Pacific water. In contrast, picoeukaryotes formed a maximum subsurface abundance corresponding to the subsurface Chl a maximum. In the mixed HNLC waters, the cell abundance and biomass of the three picophytoplankton groups were slightly lower than those in the warm pool. Due to a cyclonic eddy, the contours of the maximum subsurface Prochlorococcus abundance were uplifted, evidently with a lower value than the surrounding water. Synechococcus abundance varied greatly in patches, forming a weakly high subsurface peak when the isothermal layer rose to the near-surface (<50 m). The subsurface maximum picoeukaryote abundance was also highly consistent with that of the subsurface Chl a maximum. Correlation analysis and generalized additive models of environmental factors showed that nutrient availability had a two-faceted role in regulating the spatial patterns of picophytoplankton in diverse latitudinal and meridional environments. We concluded through regression that temperature and light irradiance were the key determinants of picophytoplankton variability in the tropical western Pacific. This study provides insights into the changing picophytoplankton community structure with potential future changing hydroclimatic force.
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Affiliation(s)
- Yu Wang
- Third Institute of OceanographyMinistry of Natural ResourcesXiamenPR China
| | - Feng Zhao
- Institute of OceanologyChinese Academy of SciencesQingdaoPR China
| | - Xuebao He
- Third Institute of OceanographyMinistry of Natural ResourcesXiamenPR China
| | - Weibo Wang
- Third Institute of OceanographyMinistry of Natural ResourcesXiamenPR China
| | - Lin Chang
- Third Institute of OceanographyMinistry of Natural ResourcesXiamenPR China
| | - Jianhua Kang
- Third Institute of OceanographyMinistry of Natural ResourcesXiamenPR China
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4
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Subsurface Bacterioplankton Structure and Diversity in the Strongly-Stratified Water Columns within the Equatorial Eastern Indian Ocean. Microorganisms 2023; 11:microorganisms11030592. [PMID: 36985166 PMCID: PMC10058062 DOI: 10.3390/microorganisms11030592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/23/2023] [Accepted: 02/23/2023] [Indexed: 03/03/2023] Open
Abstract
The consequences of climate change may directly or indirectly impact the marine biosphere. Although ocean stratification has been recognized as one of the crucial consequences of ocean warming, its impacts on several critical aspects of marine microbes remain largely unknown in the Indian Ocean. Here, we investigate the effects of water stratification, in both surface and subsurface layers, on hydrogeographic parameters and bacterioplankton diversity within the equatorial eastern Indian Ocean (EIO). Strong stratification in the upper 200 m of equatorial EIO was detected with evidential low primary productivity. The vertical bacterioplankton diversity of the whole water columns displayed noticeable variation, with lower diversity occurring in the surface layer than in the subsurface layers. Horizontal heterogeneity of bacterioplankton communities was also in the well-mixed layer among different stations. SAR11 and Prochlorococcus displayed uncharacteristic low abundance in the surface water. Some amplicon sequence variants (ASVs) were identified as potential biomarkers for their specific depths in strongly-stratified water columns. Thus, barriers resulting from stratification are proposed to function as an ‘ASV filter’ to regulate the vertical bacterioplankton community diversity along the water columns. Overall, our results suggest that the effects of stratification on the structure and diversity of bacterioplankton can extend up to the bathypelagic zone in the strongly-stratified waters of the equatorial EIO. This study provides the first insight into the effect of stratification on the subsurface microbial communities in the equatorial eastern Indian Ocean.
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Edwards KF, Li Q, McBeain KA, Schvarcz CR, Steward GF. Trophic strategies explain the ocean niches of small eukaryotic phytoplankton. Proc Biol Sci 2023; 290:20222021. [PMID: 36695036 PMCID: PMC9874276 DOI: 10.1098/rspb.2022.2021] [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] [Indexed: 01/26/2023] Open
Abstract
A large fraction of marine primary production is performed by diverse small protists, and many of these phytoplankton are phagotrophic mixotrophs that vary widely in their capacity to consume bacterial prey. Prior analyses suggest that mixotrophic protists as a group vary in importance across ocean environments, but the mechanisms leading to broad functional diversity among mixotrophs, and the biogeochemical consequences of this, are less clear. Here we use isolates from seven major taxa to demonstrate a tradeoff between phototrophic performance (growth in the absence of prey) and phagotrophic performance (clearance rate when consuming Prochlorococcus). We then show that trophic strategy along the autotrophy-mixotrophy spectrum correlates strongly with global niche differences, across depths and across gradients of stratification and chlorophyll a. A model of competition shows that community shifts can be explained by greater fitness of faster-grazing mixotrophs when nutrients are scarce and light is plentiful. Our results illustrate how basic physiological constraints and principles of resource competition can organize complexity in the surface ocean ecosystem.
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Affiliation(s)
- Kyle F. Edwards
- Department of Oceanography, School of Ocean and Earth Science and Technology (SOEST), University of Hawaiʻi at Mānoa, Honolulu, HI 96822, USA
| | - Qian Li
- Department of Oceanography, School of Ocean and Earth Science and Technology (SOEST), University of Hawaiʻi at Mānoa, Honolulu, HI 96822, USA,Daniel K. Inouye Center for Microbial Oceanography: Research and Education, School of Ocean and Earth Science and Technology (SOEST), University of Hawaiʻi at Mānoa, Honolulu, HI 96822, USA,School of Oceanography, Shanghai Jiao Tong University, 1954 Huashan Rd, Shanghai Shi, Xuhui Qu 200240, China
| | - Kelsey A. McBeain
- Department of Oceanography, School of Ocean and Earth Science and Technology (SOEST), University of Hawaiʻi at Mānoa, Honolulu, HI 96822, USA
| | - Christopher R. Schvarcz
- Department of Oceanography, School of Ocean and Earth Science and Technology (SOEST), University of Hawaiʻi at Mānoa, Honolulu, HI 96822, USA,Daniel K. Inouye Center for Microbial Oceanography: Research and Education, School of Ocean and Earth Science and Technology (SOEST), University of Hawaiʻi at Mānoa, Honolulu, HI 96822, USA
| | - Grieg F. Steward
- Department of Oceanography, School of Ocean and Earth Science and Technology (SOEST), University of Hawaiʻi at Mānoa, Honolulu, HI 96822, USA,Daniel K. Inouye Center for Microbial Oceanography: Research and Education, School of Ocean and Earth Science and Technology (SOEST), University of Hawaiʻi at Mānoa, Honolulu, HI 96822, USA
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6
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Stüeken EE, Prave AR. Diagenetic nutrient supplies to the Proterozoic biosphere archived in divergent nitrogen isotopic ratios between kerogen and silicate minerals. GEOBIOLOGY 2022; 20:623-633. [PMID: 35749131 PMCID: PMC9544726 DOI: 10.1111/gbi.12507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 05/13/2022] [Accepted: 05/20/2022] [Indexed: 06/15/2023]
Abstract
Nitrogen isotopes and abundances in sedimentary rocks have become an important tool for reconstructing biogeochemical cycles in ancient ecosystems. There are two archives of nitrogen in the rock record, namely kerogen-bound amines and silicate-bound ammonium, and it is well documented that the isotopic ratios of these two archives can be offset from one another. This offset has been observed to increase with metamorphic grade, suggesting that it may be related to the bonding environment in differing nitrogen host phases and associated equilibrium isotope fractionation. However, theoretical bounds for this effect have not been established, and it remains possible that some isotopic offsets predate metamorphism. In support of this hypothesis, we report an unexpectedly large isotopic offset of 4-5‰ in siltstones of very low metamorphic grade from the late Mesoproterozoic Diabaig Formation in NW Scotland (1.0 Ga). Carbon to nitrogen ratios of bulk rocks are 2-3 times lower than in other Mesoproterozoic sections. The rocks also contain early-formed phosphate concretions and display wrinkled surfaces on bedding planes, indicative of fossilised microbial mats. Collectively, these data are most parsimoniously interpreted as evidence of diagenetic ammonium release from microbial mats into porewaters, followed by partial oxidation to nitrite or nitrate at the sediment-water interface. This process would render residual ammonium in clays isotopically heavy, while the resulting nitrite or nitrate would be relatively lighter and captured in new biomass, leading to the observed isotopic divergence. The same diagenetic degradation pathway likely also liberated phosphate that was trapped within concretions. Diagenetic release of nutrients is known to occur in modern settings, and our data suggest that nitrogen isotopes may be a way to track this local sedimentary nutrient source in past environments. Lastly, we speculate that diagenetic nutrient recycling within Proterozoic microbial mats may have created a favourable niche for eukaryotic organisms in shallow waters.
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Affiliation(s)
- Eva E. Stüeken
- School of Earth & Environmental SciencesUniversity of St AndrewsSt AndrewsUK
| | - Anthony R. Prave
- School of Earth & Environmental SciencesUniversity of St AndrewsSt AndrewsUK
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7
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Mao F, Li W, Sim ZY, He Y, Chen Q, Yew-Hoong Gin K. Phycocyanin-rich Synechococcus dominates the blooms in a tropical estuary lake. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 311:114889. [PMID: 35287073 DOI: 10.1016/j.jenvman.2022.114889] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 02/17/2022] [Accepted: 03/09/2022] [Indexed: 06/14/2023]
Abstract
Cyanobacterial blooms challenge the safe water supply in estuary reservoirs. Yet, data are limited for the variation of phytoplankton dynamics during an algal bloom event at refined scales, which is essential for interpreting the formation and cessation of blooms. The present study investigated the biweekly abundances and dynamics of pico- and nano-phytoplankton in a tropical estuary lake following a prolonged bloom event. Flow cytometry analysis resolved eight phenotypically distinct groups of phytoplankton assigned to nano-eukaryotes (nano-EU), pico/nano-eukaryotes (PicoNano-EU), cryptophyte-like cells (CRPTO), Microcystis-like cells (MIC), pico-eukaryotes (Pico-EU) and three groups of Synechococcus-like cells. Total phytoplankton abundance ranged widely from 2.4 × 104 to 2.8 × 106 cells cm-3. The phytoplankton community was dominated by Synechococcus-like cells with high phycocyanin content (SYN-PC). Temporal dynamics of the phytoplankton community was phytoplankton- and site-specific. Peak values were observed for SYN-PC, SYN-PE2 (Synechococcus-like cells with low levels of phycoerythrin) and Pico-EU, while the temporal dynamics of other groups were less pronounced. Redundancy analysis (RDA) showed the importance of turbidity as an abiotic factor in the formation of the current SYN-PC induced blooms, and Spearman correlation analysis suggested a competitive relationship between SYN-PC and Pico-EU.
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Affiliation(s)
- Feijian Mao
- Center for Eco-Environment Research, Nanjing Hydraulic Research Institute, Nanjing, 210098, China; NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, #02-01, Singapore, 117411, Singapore; Energy and Environmental Sustainability Solutions for Megacities (E2S2) Phase II, Campus for Research Excellence and Technological Enterprise (CREATE), 1 Create Way, Singapore, 138602, Singapore
| | - Wenxuan Li
- NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, #02-01, Singapore, 117411, Singapore; Energy and Environmental Sustainability Solutions for Megacities (E2S2) Phase II, Campus for Research Excellence and Technological Enterprise (CREATE), 1 Create Way, Singapore, 138602, Singapore
| | - Zhi Yang Sim
- NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, #02-01, Singapore, 117411, Singapore; Energy and Environmental Sustainability Solutions for Megacities (E2S2) Phase II, Campus for Research Excellence and Technological Enterprise (CREATE), 1 Create Way, Singapore, 138602, Singapore
| | - Yiliang He
- Energy and Environmental Sustainability Solutions for Megacities (E2S2) Phase II, Campus for Research Excellence and Technological Enterprise (CREATE), 1 Create Way, Singapore, 138602, Singapore; School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Qiuwen Chen
- Center for Eco-Environment Research, Nanjing Hydraulic Research Institute, Nanjing, 210098, China
| | - Karina Yew-Hoong Gin
- NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, #02-01, Singapore, 117411, Singapore; Energy and Environmental Sustainability Solutions for Megacities (E2S2) Phase II, Campus for Research Excellence and Technological Enterprise (CREATE), 1 Create Way, Singapore, 138602, Singapore; Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, E1A 07-03, Singapore, 117576, Singapore.
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Cryptophyte and Photosynthetic Picoeukaryote Abundances in the Bransfield Strait during Austral Summer. WATER 2022. [DOI: 10.3390/w14020185] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A remarkable shift in the species composition and size distribution of the phytoplankton community have been observed in coastal waters along the Antarctic Peninsula over the last three decades. Smaller photoautotrophs such as cryptophytes are becoming more abundant and important for the regional ecosystems. In this study, flow cytometry was used to quantify the smallest phytoplankton in the central Bransfield Strait and explore their distribution across the strait in relation to physical and chemical properties of the two major water masses: the warmer and less saline Transitional Zonal Water with Bellingshausen Sea influence (TBW), and the cold and salty Transitional Zonal Water with Weddell Sea influence (TWW). Pico- and nano-phytoplankton clusters were distinguished and enumerated in the cytograms: photosynthetic picoeukaryotes, cryptophytes (about 9 µm in size), and smaller (3 µm) nanophytoplankton. It was shown that nanophytoplankton developed higher abundances and biomasses in the warmer and less saline TBW. This biotope was characterized by a more diverse community with a pronounced dominance of Cryptophyta in terms of biomass. The results support the hypothesis that increasing melt-water input can potentially support spatial and temporal extent of cryptophytes. The replacement of large diatoms with small cryptophytes leads to a significant shift in trophic processes in favor of the consumers such as salps, which able to graze on smaller prey.
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Bouvy M, Bélières A, Carré C, Got P, Pagano M, Agogué H, Bec B, Roques C, Bigot L, Chabanet P, Dupuy C. Do microbial planktonic communities reflect the ecological changes of Glorieuses coral reefs (Iles Eparses, Western Indian Ocean)? MARINE POLLUTION BULLETIN 2022; 174:113218. [PMID: 34952405 DOI: 10.1016/j.marpolbul.2021.113218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 11/22/2021] [Accepted: 11/24/2021] [Indexed: 06/14/2023]
Abstract
Ecological baselines for the structure and functioning of ecosystems in the absence of human activity can provide essential information on their health status. The Glorieuses islands are located in the Western Indian Ocean (WIO) and can be considered as "pristine" ecosystems that have not been subjected to anthropogenic pressure. Their nutrient context and the microbial assemblages were assessed by determining the abundance of heterotrophic prokaryotes (archaea and bacteria), picocyanobacteria, picoeukaryotes, microphytoplankton and protozooplankton communities in five stations, during two contrasted periods (November 2015 and May 2016). Chlorophyll-a concentrations were always under 1 μg/L and associated to very low levels in orthophosphates, nitrate and dissolved organic carbon, revealing an ultra-oligotrophic status for the Glorieuses waters. Picocyanobacteria confirmed the ultra-oligotrophic status with a predominance of Synechococcus. Zeaxanthin associated with the presence of picocyanobacteria represented the major pigment in both surveys. Three indices of diversity (species richness, Shannon and Pielou indexes) from microscopy observations highlighted the difference of diversity in microphytoplankton between the surveys. A focus on a 16S metabarcoding approach showed a high dominance of picocyanobacteria, Alpha- and Gammaproteobacteria, regardless of station or period. Multivariate analyses (co-inertia analyses) revealed a strong variability of ecological conditions between the two periods, with (i) high nutrient concentrations and heterotrophic nanoflagellate abundance in November 2015, and (ii) high heterotrophic prokaryote and picoeukaryote abundance in May 2016. The impact of a category 5 tropical cyclone (Fantala) on the regional zone in April 2016 is also advanced to explain these contrasted situations. Relative importance of top-down factors between bacterial and heterotrophic nanoflagellates was observed in November 2015 with an active microbial food web. All the results indicate that three microbial indexes potentially can be considered to assess the ecological change in Glorieuses marine waters.
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Affiliation(s)
- Marc Bouvy
- Marine Diversity, Exploitation and Conservation (MARBEC), Université de Montpellier, IRD, Ifremer, CNRS, France; Université de Montpellier, Place Eugene Bataillon, Case 093, 34095 Montpellier, Cedex 5, France.
| | - Alice Bélières
- Marine Diversity, Exploitation and Conservation (MARBEC), Université de Montpellier, IRD, Ifremer, CNRS, France; Université de Montpellier, Place Eugene Bataillon, Case 093, 34095 Montpellier, Cedex 5, France
| | - Claire Carré
- Marine Diversity, Exploitation and Conservation (MARBEC), Université de Montpellier, IRD, Ifremer, CNRS, France; Université de Montpellier, Place Eugene Bataillon, Case 093, 34095 Montpellier, Cedex 5, France
| | - Patrice Got
- Marine Diversity, Exploitation and Conservation (MARBEC), Université de Montpellier, IRD, Ifremer, CNRS, France; Université de Montpellier, Place Eugene Bataillon, Case 093, 34095 Montpellier, Cedex 5, France
| | - Marc Pagano
- Mediterranean Institute of Oceanography (MIO), IRD, UMR 235, 13288 Marseille, Cedex 09, France
| | - Hélène Agogué
- Littoral, Environnement et Sociétés (LIENSs), La Rochelle Université, UMR 7266 CNRS-ULR, 2 Rue Olympe de Gouges, 17000 La Rochelle, Cedex, France
| | - Béatrice Bec
- Marine Diversity, Exploitation and Conservation (MARBEC), Université de Montpellier, IRD, Ifremer, CNRS, France; Université de Montpellier, Place Eugene Bataillon, Case 093, 34095 Montpellier, Cedex 5, France
| | - Cécile Roques
- Marine Diversity, Exploitation and Conservation (MARBEC), Université de Montpellier, IRD, Ifremer, CNRS, France; Université de Montpellier, Place Eugene Bataillon, Case 093, 34095 Montpellier, Cedex 5, France
| | - Lionel Bigot
- Entropie (IRD, UR, CNRS, UNC, IFREMER), Labex CORAIL, IRD-Université La Réunion, CS 92003, 97744 Saint Denis cedex 9, France
| | - Pascale Chabanet
- Entropie (IRD, UR, CNRS, UNC, IFREMER), Labex CORAIL, IRD-Université La Réunion, CS 92003, 97744 Saint Denis cedex 9, France
| | - Christine Dupuy
- Littoral, Environnement et Sociétés (LIENSs), La Rochelle Université, UMR 7266 CNRS-ULR, 2 Rue Olympe de Gouges, 17000 La Rochelle, Cedex, France
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10
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Ford BA, Sullivan GJ, Moore L, Varkey D, Zhu H, Ostrowski M, Mabbutt BC, Paulsen IT, Shah BS. Functional characterisation of substrate-binding proteins to address nutrient uptake in marine picocyanobacteria. Biochem Soc Trans 2021; 49:2465-2481. [PMID: 34882230 PMCID: PMC8786288 DOI: 10.1042/bst20200244] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 11/03/2021] [Accepted: 11/16/2021] [Indexed: 12/05/2022]
Abstract
Marine cyanobacteria are key primary producers, contributing significantly to the microbial food web and biogeochemical cycles by releasing and importing many essential nutrients cycled through the environment. A subgroup of these, the picocyanobacteria (Synechococcus and Prochlorococcus), have colonised almost all marine ecosystems, covering a range of distinct light and temperature conditions, and nutrient profiles. The intra-clade diversities displayed by this monophyletic branch of cyanobacteria is indicative of their success across a broad range of environments. Part of this diversity is due to nutrient acquisition mechanisms, such as the use of high-affinity ATP-binding cassette (ABC) transporters to competitively acquire nutrients, particularly in oligotrophic (nutrient scarce) marine environments. The specificity of nutrient uptake in ABC transporters is primarily determined by the peripheral substrate-binding protein (SBP), a receptor protein that mediates ligand recognition and initiates translocation into the cell. The recent availability of large numbers of sequenced picocyanobacterial genomes indicates both Synechococcus and Prochlorococcus apportion >50% of their transport capacity to ABC transport systems. However, the low degree of sequence homology among the SBP family limits the reliability of functional assignments using sequence annotation and prediction tools. This review highlights the use of known SBP structural representatives for the uptake of key nutrient classes by cyanobacteria to compare with predicted SBP functionalities within sequenced marine picocyanobacteria genomes. This review shows the broad range of conserved biochemical functions of picocyanobacteria and the range of novel and hypothetical ABC transport systems that require further functional characterisation.
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Affiliation(s)
- Benjamin A. Ford
- Department of Molecular Sciences, Macquarie University, Sydney, Australia
| | | | - Lisa Moore
- Department of Molecular Sciences, Macquarie University, Sydney, Australia
| | - Deepa Varkey
- Department of Molecular Sciences, Macquarie University, Sydney, Australia
| | - Hannah Zhu
- Department of Molecular Sciences, Macquarie University, Sydney, Australia
| | - Martin Ostrowski
- Climate Change Cluster (C3), University of Technology Sydney, Sydney, Australia
| | - Bridget C. Mabbutt
- Department of Molecular Sciences, Macquarie University, Sydney, Australia
| | - Ian T. Paulsen
- Department of Molecular Sciences, Macquarie University, Sydney, Australia
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, Australia
| | - Bhumika S. Shah
- Department of Molecular Sciences, Macquarie University, Sydney, Australia
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, Australia
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11
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Phylogenetic and Phenogenetic Diversity of Synechococcus along a Yellow Sea Section Reveal Its Environmental Dependent Distribution and Co-Occurrence Microbial Pattern. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2021. [DOI: 10.3390/jmse9091018] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Synechococcus is a dominant genus of the coastal phytoplankton with an effective contribution to primary productivity. Here, the phylogenetic and phenogenetic composition of Synechococcus in the coastal Yellow Sea was addressed by sequencing marker gene methods. Meanwhile, its co-occurrence pattern with bacterial and eukaryotic microbes was further investigated based on the construction of networks. The result revealed that Synechococcus abundance ranged from 9.8 × 102 cells mL−1 to 1.6 × 105 cells mL−1, which was significantly correlated to sampling depth and nutrient contents of nitrite, ammonia, and dissolved silicon. A total of eight Synechococcus phylogenetic lineages were detected, of which clade III was dominant in most of the samples. Meanwhile, clade I increased along the water column and even reached a maximum value of 76.13% at 20 m of station B. Phenogenetically, Synechococcus PT3 was always the predominant pigment type across the whole study zone. Only salinity was significantly correlated to the phenogenetic constitution. The networks revealed that Synechococcus co-occurred with 159 prokaryotes, as well as 102 eukaryotes including such possible grazers as Gymnodinium clades and Alveolata. Potential function prediction further showed that microbes co-occurring with Synechococcus were associated with diverse element cycles, but the exact mechanism needed further experimentation to verify. This research promotes exploring regularity in the genomic composition and niche position of Synechococcus in the coastal ecosystem and is significant to further discuss its potential participation in materials circulation and bottom-up effects in microbial food webs.
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Cornec M, Claustre H, Mignot A, Guidi L, Lacour L, Poteau A, D'Ortenzio F, Gentili B, Schmechtig C. Deep Chlorophyll Maxima in the Global Ocean: Occurrences, Drivers and Characteristics. GLOBAL BIOGEOCHEMICAL CYCLES 2021; 35:e2020GB006759. [PMID: 35860208 PMCID: PMC9285500 DOI: 10.1029/2020gb006759] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 03/05/2021] [Accepted: 03/09/2021] [Indexed: 05/28/2023]
Abstract
Stratified oceanic systems are characterized by the presence of a so-called Deep Chlorophyll a Maximum (DCM) not detectable by ocean color satellites. A DCM can either be a phytoplankton (carbon) biomass maximum (Deep Biomass Maximum, DBM), or the consequence of photoacclimation processes (Deep photoAcclimation Maximum, DAM) resulting in the increase of chlorophyll a per phytoplankton carbon. Even though these DCM (further qualified as either DBMs or DAMs) have long been studied, no global-scale assessment has yet been undertaken and large knowledge gaps still remain in relation to the environmental drivers responsible for their formation and maintenance. In order to investigate their spatial and temporal variability in the open ocean, we use a global data set acquired by more than 500 Biogeochemical-Argo floats given that DCMs can be detected from the comparative vertical distribution of chlorophyll a concentrations and particulate backscattering coefficients. Our findings show that the seasonal dynamics of the DCMs are clearly region-dependent. High-latitude environments are characterized by a low occurrence of intense DBMs, restricted to summer. Meanwhile, oligotrophic regions host permanent DAMs, occasionally replaced by DBMs in summer, while subequatorial waters are characterized by permanent DBMs benefiting from favorable conditions in terms of both light and nutrients. Overall, the appearance and depth of DCMs are primarily driven by light attenuation in the upper layer. Our present assessment of DCM occurrence and of environmental conditions prevailing in their development lay the basis for a better understanding and quantification of their role in carbon budgets (primary production and export).
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Affiliation(s)
- M. Cornec
- CNRS & Sorbonne UniversitéLaboratoire d'Océanographie de Villefranche, LOVVillefranche‐sur‐MerFrance
| | - H. Claustre
- CNRS & Sorbonne UniversitéLaboratoire d'Océanographie de Villefranche, LOVVillefranche‐sur‐MerFrance
| | - A. Mignot
- Mercator Océan InternationalRamonville‐Saint‐AgneFrance
| | - L. Guidi
- CNRS & Sorbonne UniversitéLaboratoire d'Océanographie de Villefranche, LOVVillefranche‐sur‐MerFrance
| | - L. Lacour
- Takuvik Joint International LaboratoryLaval University (Canada) ‐ CNRS (France)Département de biologie et Québec‐OcéanUniversité de LavalQuébecQCCanada
| | - A. Poteau
- CNRS & Sorbonne UniversitéLaboratoire d'Océanographie de Villefranche, LOVVillefranche‐sur‐MerFrance
| | - F. D'Ortenzio
- CNRS & Sorbonne UniversitéLaboratoire d'Océanographie de Villefranche, LOVVillefranche‐sur‐MerFrance
| | - B. Gentili
- CNRS & Sorbonne UniversitéLaboratoire d'Océanographie de Villefranche, LOVVillefranche‐sur‐MerFrance
| | - C. Schmechtig
- CNRS & Sorbonne UniversitéLaboratoire d'Océanographie de Villefranche, LOVVillefranche‐sur‐MerFrance
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Lange PK, Jeremy Werdell P, Erickson ZK, Dall'Olmo G, Brewin RJW, Zubkov MV, Tarran GA, Bouman HA, Slade WH, Craig SE, Poulton NJ, Bracher A, Lomas MW, Cetinić I. Radiometric approach for the detection of picophytoplankton assemblages across oceanic fronts. OPTICS EXPRESS 2020; 28:25682-25705. [PMID: 32906854 DOI: 10.1364/oe.398127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 08/03/2020] [Indexed: 06/11/2023]
Abstract
Cell abundances of Prochlorococcus, Synechococcus, and autotrophic picoeukaryotes were estimated in surface waters using principal component analysis (PCA) of hyperspectral and multispectral remote-sensing reflectance data. This involved the development of models that employed multilinear correlations between cell abundances across the Atlantic Ocean and a combination of PCA scores and sea surface temperatures. The models retrieve high Prochlorococcus abundances in the Equatorial Convergence Zone and show their numerical dominance in oceanic gyres, with decreases in Prochlorococcus abundances towards temperate waters where Synechococcus flourishes, and an emergence of picoeukaryotes in temperate waters. Fine-scale in-situ sampling across ocean fronts provided a large dynamic range of measurements for the training dataset, which resulted in the successful detection of fine-scale Synechococcus patches. Satellite implementation of the models showed good performance (R2 > 0.50) when validated against in-situ data from six Atlantic Meridional Transect cruises. The improved relative performance of the hyperspectral models highlights the importance of future high spectral resolution satellite instruments, such as the NASA PACE mission's Ocean Color Instrument, to extend our spatiotemporal knowledge about ecologically relevant phytoplankton assemblages.
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Small phytoplankton dominate western North Atlantic biomass. ISME JOURNAL 2020; 14:1663-1674. [PMID: 32231247 PMCID: PMC7305139 DOI: 10.1038/s41396-020-0636-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 03/06/2020] [Accepted: 03/16/2020] [Indexed: 02/02/2023]
Abstract
The North Atlantic phytoplankton spring bloom is the pinnacle in an annual cycle that is driven by physical, chemical, and biological seasonality. Despite its important contributions to the global carbon cycle, transitions in plankton community composition between the winter and spring have been scarcely examined in the North Atlantic. Phytoplankton composition in early winter was compared with latitudinal transects that captured the subsequent spring bloom climax. Amplicon sequence variants (ASVs), imaging flow cytometry, and flow-cytometry provided a synoptic view of phytoplankton diversity. Phytoplankton communities were not uniform across the sites studied, but rather mapped with apparent fidelity onto subpolar- and subtropical-influenced water masses of the North Atlantic. At most stations, cells < 20-µm diameter were the main contributors to phytoplankton biomass. Winter phytoplankton communities were dominated by cyanobacteria and pico-phytoeukaryotes. These transitioned to more diverse and dynamic spring communities in which pico- and nano-phytoeukaryotes, including many prasinophyte algae, dominated. Diatoms, which are often assumed to be the dominant phytoplankton in blooms, were contributors but not the major component of biomass. We show that diverse, small phytoplankton taxa are unexpectedly common in the western North Atlantic and that regional influences play a large role in modulating community transitions during the seasonal progression of blooms.
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Mena C, Reglero P, Hidalgo M, Sintes E, Santiago R, Martín M, Moyà G, Balbín R. Phytoplankton Community Structure Is Driven by Stratification in the Oligotrophic Mediterranean Sea. Front Microbiol 2019; 10:1698. [PMID: 31396196 PMCID: PMC6667633 DOI: 10.3389/fmicb.2019.01698] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 07/10/2019] [Indexed: 12/05/2022] Open
Abstract
The phytoplankton community composition, structure, and biomass were investigated under stratified and oligotrophic conditions during summer for three consecutive years in the Mediterranean Sea. Our results reveal that the phytoplankton community structure was strongly influenced by vertical stratification. The thermocline separated two different phytoplankton communities in the two layers of the euphotic zone, characterized by different nutrient and light availability. Picoplankton dominated in terms of abundance and biomass at all the stations sampled and throughout the photic zone. However, the structure of the picoplanktonic community changed with depth, with Synechococcus and heterotrophic prokaryotes dominating in surface waters down to the base of the thermocline, and Prochlorococcus and picoeukaryotes contributing relatively more to the community in the deep chlorophyll maximum (DCM). Light and nutrient availability also influenced the communities at the DCM layer. Prochlorococcus prevailed in deeper DCM waters characterized by lower light intensities and higher picophytoplankton abundance was related to lower nutrient concentrations at the DCM. Picoeukaryotes were the major phytoplankton contributors to carbon biomass at surface (up to 80%) and at DCM (more than 40%). Besides, contrarily to the other phytoplankton groups, picoeukaryotes cell size progressively decreased with depth. Our research shows that stratification is a major factor determining the phytoplankton community structure; and underlines the role that picoeukaryotes might play in the carbon flux through the marine food web, with implications for the community metabolism and carbon fate in the ecosystem.
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Affiliation(s)
- Catalina Mena
- Ecosystem Oceanography Group (GRECO), Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears, Palma, Spain
| | - Patricia Reglero
- Ecosystem Oceanography Group (GRECO), Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears, Palma, Spain
| | - Manuel Hidalgo
- Ecosystem Oceanography Group (GRECO), Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears, Palma, Spain
| | - Eva Sintes
- Ecosystem Oceanography Group (GRECO), Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears, Palma, Spain.,Department of Limnology and Bio-Oceanography, University of Vienna, Vienna, Austria
| | - Rocío Santiago
- Ecosystem Oceanography Group (GRECO), Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears, Palma, Spain
| | - Melissa Martín
- Ecosystem Oceanography Group (GRECO), Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears, Palma, Spain
| | - Gabriel Moyà
- Departament de Biologia, Universitat de les Illes Balears, Palma, Spain
| | - Rosa Balbín
- Ecosystem Oceanography Group (GRECO), Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears, Palma, Spain
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16
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Effect of Water Column Stability on Surface Chlorophyll and Time Lags under Different Nutrient Backgrounds in a Deep Reservoir. WATER 2019. [DOI: 10.3390/w11071504] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Hydrodynamic conditions are considered to be very important in the control of algal blooms. Weekly or daily measurements may miss some important events in the hydrodynamic process, resulting in inaccurate evaluations of the impacts of hydrodynamics on phytoplankton. In this study, high-frequency (15-min interval) measurements were used to analyze the effect of water column stability on surface chlorophyll a (Chl a) and lag time under different nutrient backgrounds during a cyanobacterial bloom in the Three Gorges Reservoir, China. Cross-correlation analysis between the relative water column stability (RWCS) and Chl a was performed at different stages. The results showed that the RWCS above the euphotic depth influenced the surface Chl a concentration most significantly. A lower RWCS (<20) limited the increase in the Chl a concentration, and a higher RWCS caused a significant increase in Chl a only when nutrients were not limited (TN/TP < 29) and light and temperature conditions were suitable. It took a short time for a higher RWCS to significantly increase the surface Chl a concentration compared with a lower RWCS. When the waterbody had a very low Chl a concentration (almost 0), approximately 2 days were needed to significantly increase the Chl a concentration, while approximately only half an hour was needed when the background concentration of Chl a was slightly higher. During the bloom period, a decline in the RWCS significantly decreased the Chl a in a very short time (approximately half an hour). Reducing the water column stability could be a good approach to control cyanobacterial blooms.
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Mucko M, Bosak S, Casotti R, Balestra C, Ljubešić Z. Winter picoplankton diversity in an oligotrophic marginal sea. Mar Genomics 2018; 42:14-24. [PMID: 30249373 DOI: 10.1016/j.margen.2018.09.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 09/10/2018] [Accepted: 09/12/2018] [Indexed: 01/01/2023]
Abstract
Marine picoplankton, unicellular organisms with cell sizes up to 3 μm in diameter, numerically dominate marine ecosystems, encompassing Archaea, Bacteria, Eukarya (protists and fungi) as well as viruses. Autotrophic and heterotrophic picoplankton abundance and community composition with a focus on picoeukaryotes (PEs) were investigated in the winter of 2016 at three stations along a coast-to-offshore transect in the southern Adriatic Sea. Abundances were estimated by flow cytometry, while community composition by Illumina High-Throughput Sequencing (HTS) of 16S and 18S rRNA genes. The photosynthetic picoplankton diversity was also investigated by High-Performance Liquid Chromatography (HPLC) of liposoluble pigments. Heterotrophic bacteria and cyanobacteria (Prochlorococcus and Synechococcus) accounted for up to 7 × 105; 2.3 × 104 and 2.5 × 104 cells mL-1, respectively, while photosynthetic picoeukaryotes peaked with 3 × 103 cells mL-1. Prokaryotes, as revealed by HTS were dominated by Alphaproteobacteria (mainly SAR11, 44.91% of total 16S sequence reads), followed by Gammaproteobacteria (Oceanospirillales and Pseudomonadales, 14.96%), Bacteroidetes (mainly Flavobacteriales, 13%), Cyanobacteria (Prochlorococcus and Synechococcus, 9.52%), Marinimicrobia (SAR406, 7.97%), Deltaproteobacteria (SAR324, 3.83%), Actinobacteria (2.24%) and Chloroflexi (SAR202, 1.90%). Photosynthetic pigment concentrations were very low (12.12 μgL-1 at the most) and taxonomic pigments could be attributed to Prochlorococcus, Synechococcus, Prymnesiophyceae, Bacillariophyceae, Chrysophyceae, and Prasinophyceae. HTS data revealed that PEs were dominated by heterotrophs, such as Syndiniophyceae, parasitic dinoflagellates (79.67% of total 18S sequence reads), Dinophyceae (8.7%) and the radiolarians Collodaria belonging to Sphaerozoidae (22.1%) and Spumellaria (5.0%). On the other hand, photoautotrophs, including Chlorophyta (Mamiellophyceae, Prasinophyceae, Trebouxiophyceae, and Ulvophyceae), Stramenopiles (Bacillariophyta, Chrysophyceae, Dictyochophyceae, Pelagophyceae), photoautotrophic Cryptophyta and some Haptophyta (Prymnesiophyceae), did not exceed 5% of total sequence reads. This study provides the first snapshot of the PEs diversity in oligotrophic euphotic waters of the southern Adriatic Sea, hence setting the stage for large-scale surveying and characterization of the eukaryotic diversity in the entire basin.
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Affiliation(s)
- Maja Mucko
- University of Zagreb, Faculty of Science, Department of Biology, Rooseveltov trg 6, 10000 Zagreb, Croatia
| | - Sunčica Bosak
- University of Zagreb, Faculty of Science, Department of Biology, Rooseveltov trg 6, 10000 Zagreb, Croatia
| | - Raffaella Casotti
- Stazione Zoologica Anton Dohrn, Department of Integrative Marine Ecology, Villa Comunale, 80121 Naples, Italy
| | - Cecilia Balestra
- Stazione Zoologica Anton Dohrn, Department of Integrative Marine Ecology, Villa Comunale, 80121 Naples, Italy
| | - Zrinka Ljubešić
- University of Zagreb, Faculty of Science, Department of Biology, Rooseveltov trg 6, 10000 Zagreb, Croatia.
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18
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Scratching Beneath the Surface: A Model to Predict the Vertical Distribution of Prochlorococcus Using Remote Sensing. REMOTE SENSING 2018. [DOI: 10.3390/rs10060847] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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19
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Shi X, Li S, Liu C, Zhang M, Liu M. Community structure of photosynthetic picoeukaryotes differs in lakes with different trophic statuses along the middle-lower reaches of the Yangtze River. FEMS Microbiol Ecol 2018; 94:4817532. [DOI: 10.1093/femsec/fiy011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Accepted: 01/18/2018] [Indexed: 02/04/2023] Open
Affiliation(s)
- Xiaoli Shi
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Shengnan Li
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Changqing Liu
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Min Zhang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Mixue Liu
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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20
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Microbial planktonic communities in the Red Sea: high levels of spatial and temporal variability shaped by nutrient availability and turbulence. Sci Rep 2017; 7:6611. [PMID: 28747798 PMCID: PMC5529573 DOI: 10.1038/s41598-017-06928-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 06/28/2017] [Indexed: 12/20/2022] Open
Abstract
The semi-enclosed nature of the Red Sea (20.2°N-38.5°N) makes it a natural laboratory to study the influence of environmental gradients on microbial communities. This study investigates the composition and structure of microbial prokaryotes and eukaryotes using molecular methods, targeting ribosomal RNA genes across different regions and seasons. The interaction between spatial and temporal scales results in different scenarios of turbulence and nutrient conditions allowing for testing of ecological theory that categorizes the response of the plankton community to these variations. The prokaryotic reads are mainly comprised of Cyanobacteria and Proteobacteria (Alpha and Gamma), with eukaryotic reads dominated by Dinophyceae and Syndiniophyceae. Periodic increases in the proportion of Mamiellophyceae and Bacillariophyceae reads were associated with alterations in the physical oceanography leading to nutrient increases either through the influx of Gulf of Aden Intermediate Water (south in the fall) or through water column mixing processes (north in the spring). We observed that in general dissimilarity amongst microbial communities increased when nutrient concentrations were higher, whereas richness (observed OTUs) was higher in scenarios of higher turbulence. Maximum abundance models showed the differential responses of dominant taxa to temperature giving an indication how taxa will respond as waters become warmer and more oligotrophic.
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21
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Liang Y, Zhang Y, Zhang Y, Luo T, Rivkin RB, Jiao N. Distributions and relationships of virio- and picoplankton in the epi-, meso- and bathypelagic zones of the Western Pacific Ocean. FEMS Microbiol Ecol 2016; 93:fiw238. [PMID: 27915283 DOI: 10.1093/femsec/fiw238] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 07/18/2016] [Accepted: 11/23/2016] [Indexed: 11/13/2022] Open
Abstract
Virio- and picoplankton mediate important biogeochemical processes and the environmental factors that regulate their dynamics, and the virus-host interactions are incompletely known, especially in the deep sea. Here we report on their distributions and relationships with environmental factors at 21 stations covering a latitudinal range (2-23° N) in the Western Pacific Ocean. This region is characterized by a complex western boundary current system. Synechococcus, autotrophic picoeukaryotes, heterotrophic prokaryotes and virus-like particles (VLPs) were high (<2.4 × 102-6.3 × 104, <34-2.8 × 103, 3.9 × 104-1.3 × 106 cells mL-1 and 5.1 × 105-2.7 × 107 mL-1, respectively), and Prochlorococcus were low (<2.3 × 102-1.0 × 105 cells mL-1) in the Luzon Strait and the four most southerly stations, where upwelling occurs. Covariations in the abundances of VLPs with heterotrophic and autotrophic picoplankton, and their correlation (i.e. r2 = 0.63 and 0.52, respectively) suggested a strong host dependence in the epi- and mesopelagic zones. In the bathypelagic zone, only abiotic factors significantly influenced VLPs abundance variation (r2 = 0.12). This study shows that the dynamics of virio- and picoplankton in this Western Pacific are controlled by suite of complex and depth-dependent relationship among physical and biological factors that in turn link the physical hydrography of the western boundary current system with microbial-mediated biogeochemical processes.
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Affiliation(s)
- Yantao Liang
- Research Center for Marine Biology and Carbon Sequestration, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China.,Institute of Marine Microbes and Ecospheres, State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361101, China
| | - Yongyu Zhang
- Research Center for Marine Biology and Carbon Sequestration, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
| | - Yao Zhang
- Institute of Marine Microbes and Ecospheres, State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361101, China
| | - Tingwei Luo
- Institute of Marine Microbes and Ecospheres, State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361101, China
| | - Richard B Rivkin
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL A1C 5S7, Canada
| | - Nianzhi Jiao
- Institute of Marine Microbes and Ecospheres, State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361101, China
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Chandler JW, Lin Y, Gainer PJ, Post AF, Johnson ZI, Zinser ER. Variable but persistent coexistence of Prochlorococcus ecotypes along temperature gradients in the ocean's surface mixed layer. ENVIRONMENTAL MICROBIOLOGY REPORTS 2016; 8:272-284. [PMID: 26743532 DOI: 10.1111/1758-2229.12378] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Accepted: 12/31/2015] [Indexed: 06/05/2023]
Abstract
The vast majority of the phytoplankton communities in surface mixed layer of the oligotrophic ocean are numerically dominated by one of two ecotypes of Prochlorococcus, eMIT9312 or eMED4. In this study, we surveyed large latitudinal transects in the Atlantic and Pacific Ocean to determine if these ecotypes discretely partition the surface mixed layer niche, or if populations exist as a continuum along key environmental gradients, particularly temperature. Transitions of dominance occurred at approximately 19-21°C, with the eMED4 ecotype dominating the colder, and eMIT9312 ecotype dominating the warmer regions. Within these zones of regional dominance, however, the minority ecotype was not competed to extinction. Rather, a robust log-linear relationship between ecotype ratio and temperature characterized this stabilized coexistence: for every 2.5°C increase in temperature, the eMIT9312:eMED4 ratio increased by an order of magnitude. This relationship was observed in both quantitative polymerase chain reaction and in pyrosequencing assays. Water column stratification also contributed to the ecotype ratio along the basin-scale transects, but to a lesser extent. Finally, instances where the ratio of the eMED4 and eMIT9312 abundances did not correlate well with temperature were identified. Such occurrences are likely due to changes in water temperatures outpacing changes in community structure.
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Affiliation(s)
- Jeremy W Chandler
- Department of Microbiology, The University of Tennessee, M409 WLS, Knoxville, TN, 37966, USA
| | - Yajuan Lin
- Nicholas School of the Environment and Earth Sciences, Duke University, 135 Marine Lab Rd., Beaufort, NC, 28516, USA
| | - P Jackson Gainer
- Department of Microbiology, The University of Tennessee, M409 WLS, Knoxville, TN, 37966, USA
| | - Anton F Post
- Graduate School of Oceanography, The University of Rhode Island, 220 South Ferry Road, Narragansett, RI, 02882, USA
| | - Zackary I Johnson
- Nicholas School of the Environment and Earth Sciences, Duke University, 135 Marine Lab Rd., Beaufort, NC, 28516, USA
| | - Erik R Zinser
- Department of Microbiology, The University of Tennessee, M409 WLS, Knoxville, TN, 37966, USA
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Williams AK, McInnes AS, Rooker JR, Quigg A. Changes in Microbial Plankton Assemblages Induced by Mesoscale Oceanographic Features in the Northern Gulf of Mexico. PLoS One 2015; 10:e0138230. [PMID: 26375709 PMCID: PMC4574113 DOI: 10.1371/journal.pone.0138230] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 08/27/2015] [Indexed: 11/27/2022] Open
Abstract
Mesoscale circulation generated by the Loop Current in the Northern Gulf of Mexico (NGOM) delivers growth-limiting nutrients to the microbial plankton of the euphotic zone. Consequences of physicochemically driven community shifts on higher order consumers and subsequent impacts on the biological carbon pump remain poorly understood. This study evaluates microbial plankton <10 μm abundance and community structure across both cyclonic and anti-cyclonic circulation features in the NGOM using flow cytometry (SYBR Green I and autofluorescence parameters). Non-parametric multivariate hierarchical cluster analyses indicated that significant spatial variability in community structure exists such that stations that clustered together were defined as having a specific ‘microbial signature’ (i.e. statistically homogeneous community structure profiles based on relative abundance of microbial groups). Salinity and a combination of sea surface height anomaly and sea surface temperature were determined by distance based linear modeling to be abiotic predictor variables significantly correlated to changes in microbial signatures. Correlations between increased microbial abundance and availability of nitrogen suggest nitrogen-limitation of microbial plankton in this open ocean area. Regions of combined coastal water entrainment and mesoscale convergence corresponded to increased heterotrophic prokaryote abundance relative to autotrophic plankton. The results provide an initial assessment of how mesoscale circulation potentially influences microbial plankton abundance and community structure in the NGOM.
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Affiliation(s)
- Alicia K. Williams
- Department of Oceanography, Texas A&M University, College Station, Texas, United States of America
- * E-mail:
| | - Allison S. McInnes
- Department of Oceanography, Texas A&M University, College Station, Texas, United States of America
- Climate Change Cluster, University of Technology, Sydney, Australia
| | - Jay R. Rooker
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, Texas, United States of America
- Department of Wildlife and Fisheries, Texas A&M University, College Station, Texas, United States of America
| | - Antonietta Quigg
- Department of Oceanography, Texas A&M University, College Station, Texas, United States of America
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, Texas, United States of America
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Techtmann SM, Fortney JL, Ayers KA, Joyner DC, Linley TD, Pfiffner SM, Hazen TC. The unique chemistry of Eastern Mediterranean water masses selects for distinct microbial communities by depth. PLoS One 2015; 10:e0120605. [PMID: 25807542 PMCID: PMC4373936 DOI: 10.1371/journal.pone.0120605] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 01/24/2015] [Indexed: 11/26/2022] Open
Abstract
The waters of the Eastern Mediterranean are characterized by unique physical and chemical properties within separate water masses occupying different depths. Distinct water masses are present throughout the oceans, which drive thermohaline circulation. These water masses may contain specific microbial assemblages. The goal of this study was to examine the effect of physical and geological phenomena on the microbial community of the Eastern Mediterranean water column. Chemical measurements were combined with phospholipid fatty acid (PLFA) analysis and high-throughput 16S rRNA sequencing to characterize the microbial community in the water column at five sites. We demonstrate that the chemistry and microbial community of the water column were stratified into three distinct water masses. The salinity and nutrient concentrations vary between these water masses. Nutrient concentrations increased with depth, and salinity was highest in the intermediate water mass. Our PLFA analysis indicated different lipid classes were abundant in each water mass, suggesting that distinct groups of microbes inhabit these water masses. 16S rRNA gene sequencing confirmed the presence of distinct microbial communities in each water mass. Taxa involved in autotrophic nitrogen cycling were enriched in the intermediate water mass suggesting that microbes in this water mass may be important to the nitrogen cycle of the Eastern Mediterranean. The Eastern Mediterranean also contains numerous active hydrocarbon seeps. We sampled above the North Alex Mud Volcano, in order to test the effect of these geological features on the microbial community in the adjacent water column. The community in the waters overlaying the mud volcano was distinct from other communities collected at similar depths and was enriched in known hydrocarbon degrading taxa. Our results demonstrate that physical phenomena such stratification as well as geological phenomena such as mud volcanoes strongly affect microbial community structure in the Eastern Mediterranean water column.
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Affiliation(s)
- Stephen M. Techtmann
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee, United States of America
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Julian L. Fortney
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee, United States of America
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Kati A. Ayers
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, United States of America
- Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Dominique C. Joyner
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee, United States of America
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Thomas D. Linley
- Ocean Lab, University of Aberdeen, Newburgh, Aberdeenshire, United Kingdom
| | - Susan M. Pfiffner
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, United States of America
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Terry C. Hazen
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee, United States of America
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, United States of America
- Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, Tennessee, United States of America
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, United States of America
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
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Suari Y, Brenner S. RGB plots as a tool for the simultaneous visualization of multiple data layers in a two dimensional space. PLoS One 2014; 9:e102903. [PMID: 25028934 PMCID: PMC4100923 DOI: 10.1371/journal.pone.0102903] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 06/25/2014] [Indexed: 11/21/2022] Open
Abstract
Visualization of multidimensional data helps in understanding complex systems and environments. We present here a red, green, blue (RGB) visualization method that can serve to display environmental properties. The saturation of each color is used to represent the concentration of a given property. The implementation of that figure is illustrated through visualization of three dissolved inorganic nutrient concentrations along a vertical transect of the Mediterranean, as well as through a vertical time series of three phytoplankton group cell numbers. The RGB figures show well known properties of the water column. In addition, they reveal some lesser-known properties, such as regions in shallow water in which the ratio of phosphorus and silica to nitrogen is high, and a deep eukariotic phytoplankton community. Visualization of such data is usually performed with three separate contour or surface plots, and occasionally two properties are presented as an overlay in a single figure. The RGB figure offers a better way to visualize the interactions among the three separate plots than is commonly available.
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Affiliation(s)
- Yair Suari
- Department of Geography and Environment, Bar-Ilan University, Ramat-Gan, Israel
| | - Steve Brenner
- Department of Geography and Environment, Bar-Ilan University, Ramat-Gan, Israel
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Edwards KF, Litchman E, Klausmeier CA. Functional traits explain phytoplankton community structure and seasonal dynamics in a marine ecosystem. Ecol Lett 2012; 16:56-63. [PMID: 23033839 DOI: 10.1111/ele.12012] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Revised: 08/31/2012] [Accepted: 09/06/2012] [Indexed: 11/29/2022]
Abstract
A fundamental yet elusive goal of ecology is to predict the structure of communities from the environmental conditions they experience. Trait-based approaches to terrestrial plant communities have shown that functional traits can help reveal the mechanisms underlying community assembly, but such approaches have not been tested on the microbes that dominate ecosystem processes in the ocean. Here, we test whether functional traits can explain community responses to seasonal environmental fluctuation, using a time series of the phytoplankton of the English Channel. We show that interspecific variation in response to major limiting resources, light and nitrate, can be well-predicted by lab-measured traits characterising light utilisation, nitrate utilisation and maximum growth rate. As these relationships were predicted a priori, using independently measured traits, our results show that functional traits provide a strong mechanistic foundation for understanding the structure and dynamics of ecological communities.
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Affiliation(s)
- Kyle F Edwards
- Kellogg Biological Station, Michigan State University, Hickory Corners, MI 49060, USA.
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Mazard S, Ostrowski M, Partensky F, Scanlan DJ. Multi-locus sequence analysis, taxonomic resolution and biogeography of marine Synechococcus. Environ Microbiol 2011; 14:372-86. [PMID: 21651684 DOI: 10.1111/j.1462-2920.2011.02514.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Conserved markers such as the 16S rRNA gene do not provide sufficient molecular resolution to identify spatially structured populations of marine Synechococcus, or 'ecotypes' adapted to distinct ecological niches. Multi-locus sequence analysis targeting seven 'core' genes was employed to taxonomically resolve Synechococcus isolates and correlate previous phylogenetic analyses encompassing a range of markers. Despite the recognized importance of lateral gene transfer in shaping the genomes of marine cyanobacteria, multi-locus sequence analysis of more than 120 isolates reflects a clonal population structure of major lineages and subgroups. A single core genome locus, petB, encoding the cytochrome b(6) subunit of the cytochrome b(6) f complex, was selected to expand our understanding of the diversity and ecology of marine Synechococcus populations. Environmental petB sequences cloned from contrasting sites highlight numerous genetically and ecologically distinct clusters, some of which represent novel, environmentally abundant clades without cultured representatives. With a view to scaling ecological analyses, the short sequence, taxonomic resolution and accurate automated alignment of petB is ideally suited to high-throughput and high-resolution sequencing projects to explore links between the ecology, evolution and biology of marine Synechococcus.
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Affiliation(s)
- Sophie Mazard
- School of Life Sciences, University of Warwick, Gibbet Hill Road, Coventry, UK
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