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Rammel T, Nagarkar M, Palenik B. Temporal and spatial diversity and abundance of cryptophytes in San Diego coastal waters. JOURNAL OF PHYCOLOGY 2024; 60:668-684. [PMID: 38721968 DOI: 10.1111/jpy.13451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 11/02/2023] [Accepted: 01/29/2024] [Indexed: 06/12/2024]
Abstract
Cryptophytes (class Cryptophyceae) are bi-flagellated eukaryotic protists with mixed nutritional modes and cosmopolitan distribution in aquatic environments. Despite their ubiquitous presence, their molecular diversity is understudied in coastal waters. Weekly 18S rRNA gene amplicon sequencing at the Scripps Institution of Oceanography pier (La Jolla, California) in 2016 revealed 16 unique cryptophyte amplicon sequence variants (ASVs), with two dominant "clade 4" ASVs. The diversity of cryptophytes was lower than what is often seen in other phytoplankton taxa. One ASV represented a known Synechococcus grazer, while the other one appeared not to have cultured representatives and an unknown potential for mixotrophy. These two dominant ASVs were negatively correlated, suggesting possible niche differentiation. The cryptophyte population in nearby San Diego Bay was surveyed in 2019 and showed the increasing dominance of a different clade 4 ASV toward the back of the bay where conditions are warmer, saltier, and shallower relative to other areas in the bay. An ASV representing a potentially chromatically acclimating cryptophyte species also suggested that San Diego Bay exerts differing ecological selection pressures than nearby coastal waters. Cryptophyte and Synechococcus cell abundance at the SIO Pier from 2011 to 2017 showed that cryptophytes were consistently present and had a significant correlation with Synechococcus abundance, but no detectable seasonality. The demonstrated mixotrophy of some cryptophytes suggests that grazing on these and perhaps other bacteria is important for their ecological success. Using several assumptions, we calculated that cryptophytes could consume up to 44% (average 6%) of the Synechococcus population per day. This implies that cryptophytes could significantly influence Synechococcus abundance.
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Affiliation(s)
- Tristin Rammel
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
| | - Maitreyi Nagarkar
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
| | - Brian Palenik
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
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Furgason CC, Smirnova AV, Dacks JB, Dunfield PF. Phytoplankton ecology in the early years of a boreal oil sands end pit lake. ENVIRONMENTAL MICROBIOME 2024; 19:3. [PMID: 38217061 PMCID: PMC10787447 DOI: 10.1186/s40793-023-00544-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 12/20/2023] [Indexed: 01/14/2024]
Abstract
BACKGROUND Base Mine Lake (BML) is the first full-scale end pit lake for the oil sands mining industry in Canada. BML sequesters oil sands tailings under a freshwater cap and is intended to develop into a functional ecosystem that can be integrated into the local watershed. The first stage of successful reclamation requires the development of a phytoplankton community supporting a typical boreal lake food web. To assess the diversity and dynamics of the phytoplankton community in BML at this reclamation stage and to set a baseline for future monitoring, we examined the phytoplankton community in BML from 2016 through 2021 using molecular methods (targeting the 23S, 18S, and 16S rRNA genes) and microscopic methods. Nearby water bodies were used as controls for a freshwater environment and an active tailings pond. RESULTS The phytoplankton community was made up of diverse bacteria and eukaryotes typical of a boreal lake. Microscopy and molecular data both identified a phytoplankton community comparable at the phylum level to that of natural boreal lakes, dominated by Chlorophyta, Cryptophyta, and Cyanophyta, with some Bacillariophyta, Ochrophyta, and Euglenophyta. Although many of the same genera were prominent in both BML and the control freshwater reservoir, there were differences at the species or ASV level. Total diversity in BML was also consistently lower than the control freshwater site, but consistently higher than the control tailings pond. The phytoplankton community composition in BML changed over the 5-year study period. Some taxa present in 2016-2019 (e.g., Choricystis) were no longer detected in 2021, while some dinophytes and haptophytes became detectable in small quantities starting in 2019-2021. Different quantification methods (qPCR analysis of 23S rRNA genes, and microscopic estimates of populations and total biomass) did not show a consistent directional trend in total phytoplankton over the 5-year study, nor was there any consistent increase in phytoplankton species diversity. The 5-year period was likely an insufficient time frame for detecting community trends, as phytoplankton communities are highly variable at the genus and species level. CONCLUSIONS BML supports a phytoplankton community composition somewhat unique from control sites (active tailings and freshwater lake) and is still changing over time. However, the most abundant genera are typical of natural boreal lakes and have the potential to support a complex aquatic food web, with many of its identified major phytoplankton constituents known to be primary producers in boreal lake environments.
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Affiliation(s)
- Chantel C Furgason
- Department of Biological Sciences, University of Calgary, 2500 University Dr. NW, Calgary, AB, Canada
| | - Angela V Smirnova
- Department of Biological Sciences, University of Calgary, 2500 University Dr. NW, Calgary, AB, Canada
| | - Joel B Dacks
- Division of Infectious Diseases, Department of Medicine and Department of Biological Sciences, University of Alberta, 116 St. and 85 Ave., Edmonton, AB, Canada
| | - Peter F Dunfield
- Department of Biological Sciences, University of Calgary, 2500 University Dr. NW, Calgary, AB, Canada.
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Wang T, Zhou Y, Li J, Qin S. Molecular insights into nitrogen constraint for niche partitioning and physiological adaptation of coastal Synechococcus assemblages. ENVIRONMENTAL RESEARCH 2023; 239:117383. [PMID: 37832763 DOI: 10.1016/j.envres.2023.117383] [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: 08/14/2023] [Revised: 09/23/2023] [Accepted: 10/11/2023] [Indexed: 10/15/2023]
Abstract
Coastal nitrogen input has substantially increased due to human activity. However, much remains unknown about the nitrogen-driven patterns and the underlying genetic basis of coastal picoplankton. To investigate the response and mechanisms of picoplankton induced by nitrogen variation, we conducted in-situ investigations using high-throughput sequencing in the Bohai Sea and performed laboratory nitrogen simulation experiments accompanied by physiological, genomic, and transcriptomic analyses, with Synechococcus as a representative. The results of in-situ investigation revealed that Synechococcus clades I, III, WPC1, and VI of subcluster 5.1 (S5.1) are prevalent in strait areas characterized by robust water exchange with the North Yellow Sea, while clades II, VIII, and IX of S5.1, as well as subcluster 5.2 (S5.2) and subcluster 5.3 (S5.3) are more abundant in central and bay areas experiencing elevated nitrate and nitrite loads. The laboratory experiments further confirmed that inorganic nitrogen is a crucial determinant of diversity and niche partitioning of Synechococcus lineages. Besides, the raising inorganic nitrogen concentration within the current in-situ range (0.1-10 μmol L-1) enhances photosynthesis and carbon fixation of Synechococcus, however further escalation of inorganic nitrogen (100 μmol L-1) may hinder these processes instead. The phenomenon could be associated with the differential expression of genes in metabolic pathways regulating nitrogen metabolism, photosynthetic system II, and photosynthesis-antenna proteins in response to nitrogen concentration and type variation. These findings expand our understanding of the impact of macronutrient variation resulting from human activities on marine picoplankton and biogeochemical cycles.
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Affiliation(s)
- Ting Wang
- Key Laboratory of Coastal Biology and Biological Resource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, China; University of Chinese Academy of Sciences, Beijing, 101408, China
| | - Yuting Zhou
- Key Laboratory of Coastal Biology and Biological Resource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, China
| | - Jialin Li
- Key Laboratory of Coastal Biology and Biological Resource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, China.
| | - Song Qin
- Key Laboratory of Coastal Biology and Biological Resource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, China.
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Schomaker RA, Richardson TL, Dudycha JL. Consequences of light spectra for pigment composition and gene expression in the cryptophyte Rhodomonas salina. Environ Microbiol 2023; 25:3280-3297. [PMID: 37845005 DOI: 10.1111/1462-2920.16523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 09/28/2023] [Indexed: 10/18/2023]
Abstract
Algae with a more diverse suite of pigments can, in principle, exploit a broader swath of the light spectrum through chromatic acclimation, the ability to maximize light capture via plasticity of pigment composition. We grew Rhodomonas salina in wide-spectrum, red, green, and blue environments and measured how pigment composition differed. We also measured expression of key light-capture and photosynthesis-related genes and performed a transcriptome-wide expression analysis. We observed the highest concentration of phycoerythrin in green light, consistent with chromatic acclimation. Other pigments showed trends inconsistent with chromatic acclimation, possibly due to feedback loops among pigments or high-energy light acclimation. Expression of some photosynthesis-related genes was sensitive to spectrum, although expression of most was not. The phycoerythrin α-subunit was expressed two-orders of magnitude greater than the β-subunit even though the peptides are needed in an equimolar ratio. Expression of genes related to chlorophyll-binding and phycoerythrin concentration were correlated, indicating a potential synthesis relationship. Pigment concentrations and expression of related genes were generally uncorrelated, implying post-transcriptional regulation of pigments. Overall, most differentially expressed genes were not related to photosynthesis; thus, examining associations between light spectrum and other organismal functions, including sexual reproduction and glycolysis, may be important.
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Affiliation(s)
| | - Tammi L Richardson
- Department of Biological Sciences, University of South Carolina, Columbia, South Carolina, USA
- School of the Earth, Ocean, & Environment, University of South Carolina, Columbia, South Carolina, USA
| | - Jeffry L Dudycha
- Department of Biological Sciences, University of South Carolina, Columbia, South Carolina, USA
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Ding X, Liu J, Liu W, Dai S, Ke Z, Guo J, Lai Y, Tan Y. Phytoplankton Communities Miniaturization Driven by Extreme Weather in Subtropical Estuary under Climate Changes. WATER RESEARCH 2023; 245:120588. [PMID: 37716296 DOI: 10.1016/j.watres.2023.120588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 09/01/2023] [Accepted: 09/05/2023] [Indexed: 09/18/2023]
Abstract
Estuarine ecosystems are subject to extreme weather and climatic events, particularly global climate change. To characterize the effects of extreme weather, such as heavy precipitation and cold waves, on phytoplankton communities, four seasonal cruises were conducted in the subtropical Pearl River Estuary. Among the main phytoplankton taxa, small (pico- and nano-sized) phytoplankton accounted for approximately 50% and 70% in the upstream estuary. In spring, summer, and autumn, small-sized phytoplankton communities were dominated by Chlorophyta (20-45%), Ochrophyta (Bacillariophyceae; 25-40%), and Dinoflagellata (20-25%), associated with high phytoplankton network stability and river discharge. In winter, small phytoplankton communities were dominated by Cryptophyta (50%), Dinoflagellata (25%), and Ochrophyta (Bacillariophyceae; 10%), which were associated with low network stability and temperature. Low light and high nutrient conditions induced by large river discharge favored the growth of the smallest known brackish Chlorophyta, such as Ostreococcus tauri. Low temperatures provided a competitive advantage for the survival of the small-sized cryptophyte genus Teleaulax, especially in the upstream estuary during the 2020/2021 extreme cold wave period. Our findings highlight the impact of extreme weather induced by climatic events on the miniaturization of phytoplankton communities in subtropical estuaries by altering temperature, light availability, and nutrient dynamics.
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Affiliation(s)
- Xiang Ding
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jiaxing Liu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
| | - Weiwei Liu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
| | - Sheng Dai
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
| | - Zhixin Ke
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
| | - Jia Guo
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yanjiao Lai
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yehui Tan
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
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Boucher C, Lacour T, Julie A, Damien R, Juel HP, Francis M. Mixotrophic lifestyle of the ichthyotoxic haptophyte, Prymnesium parvum, offered different sources of phosphorus. HARMFUL ALGAE 2023; 127:102483. [PMID: 37544668 DOI: 10.1016/j.hal.2023.102483] [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: 05/11/2023] [Revised: 07/27/2023] [Accepted: 07/28/2023] [Indexed: 08/08/2023]
Abstract
Many harmful algae are mixoplanktonic, i.e. they combine phototrophy and phagotrophy, and this ability may explain their ecological success, especially when environmental conditions are not optimal for autotrophic growth. In this study, laboratory experiments were conducted with the mixotrophic and ichthyotoxic haptophyte Prymnesium parvum (strain CCAP 946/6) to test the effects of phosphorus (P) sufficiency and deficiency on its growth rate, phagotrophic and lytic activities. P-deficient P. parvum cultures were grown without or with addition of P in the form of inorganic phosphorus (nutrients) and/or living algal prey (i.e. the cryptophyte Teleaulax amphioxeia). The ingestion rate of P. parvum and prey mortality rate were calculated using flow cytometry measurements based on pigment-derived-fluorescence to distinguish between prey, predators and digesting predators. The first aim of the study was to develop a method taking into account the rate of digestion, allowing the calculation of ingestion rates over a two-week period. Growth rates of P. parvum were higher in the treatments with live prey, irrespective of the concentration of inorganic P, and maximum growth rates were found when both inorganic and organic P in form of prey were added (0.79 ± 0.07 d-1). In addition, the mortality rate of T. amphioxeia induced by lytic compounds was 0.2 ± 0.02 d-1 in the P-deficient treatment, while no mortality was observed under P-sufficiency in the present experiments. This study also revealed the mortality due to cell lysis exceeded that of prey ingestion. Therefore, additional experiments were conducted with lysed prey cells. When grown with debris from prey cells, the mean growth rate of P. parvum was similar to monocultures without additions of prey debris (0.30 ± 0.1 vs. 0.38 ± 0.03 d-1), suggesting that P. parvum is able to grow on prey debris, but not as fast as with live prey. These results provide the first quantitative evidence over two weeks of experiment that ingestion of organic P in the form of living prey and/or debris of prey plays an important role in P. parvum growth and may explain its ecological success in a nutrient-limited environments.
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Affiliation(s)
- Clémence Boucher
- Ifremer, PHYTOX, Rue de l'Île d'Yeu, 44311 Nantes Cedex 03, France.
| | - Thomas Lacour
- Ifremer, PHYTOX, Rue de l'Île d'Yeu, 44311 Nantes Cedex 03, France
| | - André Julie
- Ifremer, PHYTOX, Rue de l'Île d'Yeu, 44311 Nantes Cedex 03, France
| | - Réveillon Damien
- Ifremer, PHYTOX, Rue de l'Île d'Yeu, 44311 Nantes Cedex 03, France
| | - Hansen Per Juel
- University of Copenhagen, Department of Biology, Marine Biological Section, Strandpromenaden 5, 3000 Helsingør, Denmark
| | - Mairet Francis
- Ifremer, PHYTOX, Rue de l'Île d'Yeu, 44311 Nantes Cedex 03, France
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Flynn KJ, Mitra A. Feeding in mixoplankton enhances phototrophy increasing bloom-induced pH changes with ocean acidification. JOURNAL OF PLANKTON RESEARCH 2023; 45:636-651. [PMID: 37483909 PMCID: PMC10361812 DOI: 10.1093/plankt/fbad030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 05/28/2023] [Indexed: 07/25/2023]
Abstract
Plankton phototrophy consumes CO2, increasing seawater pH, while heterotrophy does the converse. Elevation of pH (>8.5) during coastal blooms becomes increasingly deleterious for plankton. Mixoplankton, which can be important bloom-formers, engage in both photoautotrophy and phagoheterotrophy; in theory, this activity could create a relatively stable pH environment for plankton growth. Using a systems biology modelling approach, we explored whether different mixoplankton functional groups could modulate the environmental pH compared to the extreme activities of phototrophic phytoplankton and heterotrophic zooplankton. Activities by most mixoplankton groups do not stabilize seawater pH. Through access to additional nutrient streams from internal recycling with phagotrophy, mixoplankton phototrophy is enhanced, elevating pH; this is especially so for constitutive and plastidic specialist non-constitutive mixoplankton. Mixoplankton blooms can exceed the size of phytoplankton blooms; the synergisms of mixoplankton physiology, accessing nutrition via phagotrophy as well as from inorganic sources, enhance or augment primary production rather than depressing it. Ocean acidification will thus enable larger coastal mixoplankton blooms to form before basification becomes detrimental. The dynamics of such bloom developments will depend on whether the mixoplankton are consuming heterotrophs and/or phototrophs and how the plankton community succession evolves.
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Affiliation(s)
| | - Aditee Mitra
- School of Earth and Environmental Sciences, Main Building, Park Place, Cardiff University, Cardiff CF10 3AT, UK
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He L, Yu Z, Xu X, Zhu J, Yuan Y, Cao X, Song X. Metabarcoding analysis identifies high diversity of harmful algal bloom species in the coastal waters of the Beibu Gulf. Ecol Evol 2023; 13:e10127. [PMID: 37223313 PMCID: PMC10202623 DOI: 10.1002/ece3.10127] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 04/26/2023] [Accepted: 05/10/2023] [Indexed: 05/25/2023] Open
Abstract
Harmful algal blooms (HABs) have occurred more frequently in recent years. In this study, to investigate their potential impact in the Beibu Gulf, short-read and long-read metabarcoding analyses were combined for annual marine phytoplankton community and HAB species identification. Short-read metabarcoding showed a high level of phytoplankton biodiversity in this area, with Dinophyceae dominating, especially Gymnodiniales. Multiple small phytoplankton, including Prymnesiophyceae and Prasinophyceae, were also identified, which complements the previous lack of identifying small phytoplankton and those unstable after fixation. Of the top 20 phytoplankton genera identified, 15 were HAB-forming genera, which accounted for 47.3%-71.5% of the relative abundance of phytoplankton. Based on long-read metabarcoding, a total of 147 OTUs (PID > 97%) belonging to phytoplankton were identified at the species level, including 118 species. Among them, 37 species belonged to HAB-forming species, and 98 species were reported for the first time in the Beibu Gulf. Contrasting the two metabarcoding approaches at the class level, they both showed a predominance of Dinophyceae, and both included high abundances of Bacillariophyceae, Prasinophyceae, and Prymnesiophyceae, but the relative contents of the classes varied. Notably, the results of the two metabarcoding approaches were quite different below the genus level. The high abundance and diversity of HAB species were probably due to their special life history and multiple nutritional modes. Annual HAB species variation revealed in this study provided a basis for evaluating their potential impact on aquaculture and even nuclear power plant safety in the Beibu Gulf.
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Affiliation(s)
- Liyan He
- CAS Key Laboratory of Marine Ecology and Environmental SciencesInstitute of Oceanology, Chinese Academy of SciencesQingdaoChina
- Functional Laboratory of Marine Ecology and Environmental ScienceLaoshan LaboratoryQingdaoChina
- Center for Ocean Mega‐ScienceChinese Academy of SciencesQingdaoChina
| | - Zhiming Yu
- CAS Key Laboratory of Marine Ecology and Environmental SciencesInstitute of Oceanology, Chinese Academy of SciencesQingdaoChina
- Functional Laboratory of Marine Ecology and Environmental ScienceLaoshan LaboratoryQingdaoChina
- Center for Ocean Mega‐ScienceChinese Academy of SciencesQingdaoChina
- University of Chinese Academy of SciencesBeijingChina
| | - Xin Xu
- CAS Key Laboratory of Marine Ecology and Environmental SciencesInstitute of Oceanology, Chinese Academy of SciencesQingdaoChina
- Functional Laboratory of Marine Ecology and Environmental ScienceLaoshan LaboratoryQingdaoChina
- Center for Ocean Mega‐ScienceChinese Academy of SciencesQingdaoChina
| | - Jianan Zhu
- CAS Key Laboratory of Marine Ecology and Environmental SciencesInstitute of Oceanology, Chinese Academy of SciencesQingdaoChina
- Functional Laboratory of Marine Ecology and Environmental ScienceLaoshan LaboratoryQingdaoChina
- Center for Ocean Mega‐ScienceChinese Academy of SciencesQingdaoChina
| | - Yongquan Yuan
- CAS Key Laboratory of Marine Ecology and Environmental SciencesInstitute of Oceanology, Chinese Academy of SciencesQingdaoChina
- Functional Laboratory of Marine Ecology and Environmental ScienceLaoshan LaboratoryQingdaoChina
- Center for Ocean Mega‐ScienceChinese Academy of SciencesQingdaoChina
| | - Xihua Cao
- CAS Key Laboratory of Marine Ecology and Environmental SciencesInstitute of Oceanology, Chinese Academy of SciencesQingdaoChina
- Functional Laboratory of Marine Ecology and Environmental ScienceLaoshan LaboratoryQingdaoChina
- Center for Ocean Mega‐ScienceChinese Academy of SciencesQingdaoChina
| | - Xiuxian Song
- CAS Key Laboratory of Marine Ecology and Environmental SciencesInstitute of Oceanology, Chinese Academy of SciencesQingdaoChina
- Functional Laboratory of Marine Ecology and Environmental ScienceLaoshan LaboratoryQingdaoChina
- Center for Ocean Mega‐ScienceChinese Academy of SciencesQingdaoChina
- University of Chinese Academy of SciencesBeijingChina
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Mitra A, Flynn KJ. Low rates of bacterivory enhances phototrophy and competitive advantage for mixoplankton growing in oligotrophic waters. Sci Rep 2023; 13:6900. [PMID: 37106077 PMCID: PMC10140275 DOI: 10.1038/s41598-023-33962-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 04/21/2023] [Indexed: 04/29/2023] Open
Abstract
With climate change, oceans are becoming increasingly nutrient limited, favouring growth of prokaryotic picoplankton at the expense of the larger protist plankton whose growth support higher trophic levels. Constitutive mixoplankton (CM), microalgal plankton with innate phototrophic capability coupled with phagotrophy, graze on these picoplankton, indirectly exploiting the excellent resource acquisition abilities of the prokaryotes. However, feeding rates can be very low (e.g., a few bacteria d-1). For the first time, the significance of such low consumption rates has been quantified. We find that while prokaryote-carbon (C) supply to CM grown at non-limiting light was so low that it may appear insignificant (< 10%), contributions of nitrogen (N) and phosphorus (P) from ingestions of 1-12 prokaryotes d-1 were significant. Under limiting light, contributions of ingested C increased, also raising the contributions of N and P. The order of nutritional importance for CM growth from predation was P > N > C. Further, provision of N through internal recycling of ingested prey-N stimulates C-fixation through photosynthesis. Importantly, coupled photo-phago-mixoplanktonic activity improved CM resource affinities for both inorganic and prey-bound nutrients, enhancing the nutritional status and competitiveness of mixoplankton. With warming oceans, with increased prokaryote abundance, we expect CM to exhibit more phagotrophy.
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Affiliation(s)
- Aditee Mitra
- School of Earth and Environmental Sciences, Cardiff University, Park Place, Cardiff, CF10 3AT, Wales, UK.
| | - Kevin J Flynn
- Plymouth Marine Laboratory, Prospect Place, West Hoe, Plymouth, PL1 3DH, UK
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Microbial Community Dynamics during a Harmful Chrysochromulina leadbeateri Bloom in Northern Norway. Appl Environ Microbiol 2023; 89:e0189522. [PMID: 36622180 PMCID: PMC9888202 DOI: 10.1128/aem.01895-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
A harmful algal bloom occurred in late spring 2019 across multiple, interconnected fjords and bays in northern Norway. The event was caused by the haptophyte Chrysochromulina leadbeateri and led to severe fish mortality at several salmon aquaculture facilities. This study reports on the spatial and temporal succession dynamics of the holistic marine microbiome associated with this bloom by relating all detectable 18S and 16S rRNA gene amplicon sequence variants to the relative abundance of the C. leadbeateri focal taxon. A k-medoid clustering enabled inferences on how the causative focal taxon cobloomed with diverse groups of bacteria and microeukaryotes. These coblooming patterns showed high temporal variability and were distinct between two geographically separated time series stations during the regional harmful algal bloom. The distinct blooming patterns observed with respect to each station were poorly connected to environmental conditions, suggesting that other factors, such as biological interactions, may be at least as important in shaping the dynamics of this type of harmful algal bloom. A deeper understanding of microbiome succession patterns during these rare but destructive events will help guide future efforts to forecast deviations from the natural bloom cycles of the northern Norwegian coastal marine ecosystems that are home to intensive aquaculture activities. IMPORTANCE The 2019 Chrysochromulina leadbeateri bloom in northern Norway had a major impact on the local economy and society through its devastating effect on the aquaculture industry. However, many fail to remember that C. leadbeateri is, in fact, a common member of the seasonal marine microbiome and the same spring phytoplankton blooms that support the marine ecosystem. It is challenging to draw any conclusions about exact causation behind the harmful bloom of 2019, especially since the natural bloom cycles of C. leadbeateri are not well understood. This study begins to fill major knowledge gaps that may lead to future forecasting abilities, by providing a molecular-based investigation of the destructive 2019 bloom that presents new insights into a seasonal marine microbial ecosystem during one of these sporadically reoccurring events.
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Phycobilisome light-harvesting efficiency in natural populations of the marine cyanobacteria Synechococcus increases with depth. Commun Biol 2022; 5:727. [PMID: 35869258 PMCID: PMC9307576 DOI: 10.1038/s42003-022-03677-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 07/07/2022] [Indexed: 11/24/2022] Open
Abstract
Cyanobacteria of the genus Synechococcus play a key role as primary producers and drivers of the global carbon cycle in temperate and tropical oceans. Synechococcus use phycobilisomes as photosynthetic light-harvesting antennas. These contain phycoerythrin, a pigment-protein complex specialized for absorption of blue light, which penetrates deep into open ocean water. As light declines with depth, Synechococcus photo-acclimate by increasing both the density of photosynthetic membranes and the size of the phycobilisomes. This is achieved with the addition of phycoerythrin units, as demonstrated in laboratory studies. In this study, we probed Synechococcus populations in an oligotrophic water column habitat at increasing depths. We observed morphological changes and indications for an increase in phycobilin content with increasing depth, in summer stratified Synechococcus populations. Such an increase in antenna size is expected to come at the expense of decreased energy transfer efficiency through the antenna, since energy has a longer distance to travel. However, using fluorescence lifetime depth profile measurement approach, which is applied here for the first time, we found that light-harvesting quantum efficiency increased with depth in stratified water column. Calculated phycobilisome fluorescence quantum yields were 3.5% at 70 m and 0.7% at 130 m. Under these conditions, where heat dissipation is expected to be constant, lower fluorescence yields correspond to higher photochemical yields. During winter-mixing conditions, Synechococcus present an intermediate state of light harvesting, suggesting an acclimation of cells to the average light regime through the mixing depth (quantum yield of ~2%). Given this photo-acclimation strategy, the primary productivity attributed to marine Synechococcus should be reconsidered. Probing the population of the cyanobacterium Synechococcus in an oligotrophic water column habitat at increasing depths reveals that light-harvesting quantum efficiency increases with depth.
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Li M, Chen Y, Zhang F, Song Y, Glibert PM, Stoecker DK. A three-dimensional mixotrophic model of Karlodinium veneficum blooms for a eutrophic estuary. HARMFUL ALGAE 2022; 113:102203. [PMID: 35287934 DOI: 10.1016/j.hal.2022.102203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 01/26/2022] [Accepted: 02/05/2022] [Indexed: 06/14/2023]
Abstract
Blooms of dinoflagellate Karlodinium veneficum are widely distributed in estuarine and coastal waters and have been found to cause fish kills worldwide. K. veneficum has a mixed nutritional mode and relies on both photosynthesis and phagotrophy for growth; it is a mixotroph. Here, a model of mixotrophic growth of K. veneficum (MIXO) was developed, calibrated with previously-reported laboratory physiological data, and subsequently embedded in a 3D-coupled hydrodynamic (ROMS)-biogeochemical (RCA) model of eutrophic Chesapeake Bay, USA. The resulting ROMS-RCA-MIXO model was applied in hindcast mode to investigate seasonal and spatial distributions. Simulations showed that K. veneficum blooms occurred during June-August and were confined to the upper and middle Bay, consistent with long-term field observations. Autotrophic growth dominated in spring but heterotrophic growth dominated during the summer. The number of prey ingested by K. veneficum varied from 0.1 to 0.6 day-1 and the food vacuole content reached up to 50% of the core mixotroph biomass. The ingestion rate increased with prey density and also when P:N ratio fell below ∼0.03 (N:P ∼ 33), indicating that K. veneficum only switched to mixotrophic feeding in P-deficient waters when sufficient prey were available; this occurred during the summer months. The digestion rate increased with both the food vacuole content and temperature. The modeling analysis affirms K. veneficum as a phagotrophic 'alga' which is primarily photosynthetic but switches to mixotrophic feeding under nutrient deficient conditions.
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Affiliation(s)
- Ming Li
- University of Maryland Center for Environmental Science, Horn Point Laboratory, PO Box 775, Cambridge, Maryland 21613, U.S.A..
| | - Yuren Chen
- University of Maryland Center for Environmental Science, Horn Point Laboratory, PO Box 775, Cambridge, Maryland 21613, U.S.A
| | - Fan Zhang
- University of Maryland Center for Environmental Science, Horn Point Laboratory, PO Box 775, Cambridge, Maryland 21613, U.S.A
| | - Yang Song
- University of Maryland Center for Environmental Science, Horn Point Laboratory, PO Box 775, Cambridge, Maryland 21613, U.S.A
| | - Patricia M Glibert
- University of Maryland Center for Environmental Science, Horn Point Laboratory, PO Box 775, Cambridge, Maryland 21613, U.S.A
| | - Diane K Stoecker
- University of Maryland Center for Environmental Science, Horn Point Laboratory, PO Box 775, Cambridge, Maryland 21613, U.S.A
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Zonation of protistan plankton in a productive area of the Patagonian shelf: Potential implications for the anchovy distribution. FOOD WEBS 2021. [DOI: 10.1016/j.fooweb.2021.e00211] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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14
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Experimental identification and in silico prediction of bacterivory in green algae. THE ISME JOURNAL 2021; 15:1987-2000. [PMID: 33649548 PMCID: PMC8245530 DOI: 10.1038/s41396-021-00899-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 01/03/2021] [Accepted: 01/18/2021] [Indexed: 01/31/2023]
Abstract
While algal phago-mixotrophs play a major role in aquatic microbial food webs, their diversity remains poorly understood. Recent studies have indicated several species of prasinophytes, early diverging green algae, to be able to consume bacteria for nutrition. To further explore the occurrence of phago-mixotrophy in green algae, we conducted feeding experiments with live fluorescently labeled bacteria stained with CellTracker Green CMFDA, heat-killed bacteria stained with 5-(4,6-dichlorotriazin-2-yl) aminofluorescein (DTAF), and magnetic beads. Feeding was detected via microscopy and/or flow cytometry in five strains of prasinophytes when provided with live bacteria: Pterosperma cristatum NIES626, Pyramimonas parkeae CCMP726, Pyramimonas parkeae NIES254, Nephroselmis pyriformis RCC618, and Dolichomastix tenuilepis CCMP3274. No feeding was detected when heat-killed bacteria or magnetic beads were provided, suggesting a strong preference for live prey in the strains tested. In parallel to experimental assays, green algal bacterivory was investigated using a gene-based prediction model. The predictions agreed with the experimental results and suggested bacterivory potential in additional green algae. Our observations underline the likelihood of widespread occurrence of phago-mixotrophy among green algae, while additionally highlighting potential biases introduced when using prey proxy to evaluate bacterial ingestion by algal cells.
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An Improved Algorithm for Measuring Nitrate Concentrations in Seawater Based on Deep-Ultraviolet Spectrophotometry: A Case Study of the Aoshan Bay Seawater and Western Pacific Seawater. SENSORS 2021; 21:s21030965. [PMID: 33535502 PMCID: PMC7867073 DOI: 10.3390/s21030965] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/27/2021] [Accepted: 01/29/2021] [Indexed: 12/14/2022]
Abstract
Nowadays, it is still a challenge for commercial nitrate sensors to meet the requirement of high accuracy in a complex water. Based on deep-ultraviolet spectral analysis and a regression algorithm, a different measuring method for obtaining the concentration of nitrate in seawater is proposed in this paper. The system consists of a deuterium lamp, an optical fiber splitter module, a reflection probe, temperature and salinity sensors, and a deep-ultraviolet spectrometer. The regression model based on weighted average kernel partial least squares (WA-KPLS) algorithm together with corrections for temperature and salinity (TSC) is established. After that, the seawater samples from Western Pacific and Aoshan Bay in Qingdao, China with the addition of various nitrate concentrations are studied to verify the reliability and accuracy of the method. The results show that the TSC-WA-KPLS algorithm shows the best results when compared against the multiple linear regression (MLR) and ISUS (in situ ultraviolet spectrophotometer) algorithms in the temperatures range of 4–25 °C, with RMSEP of 0.67 µmol/L for Aoshan Bay seawater and 1.08 µmol/L for Western Pacific seawater. The method proposed in this paper is suitable for measuring the nitrate concentration in seawater with higher accuracy, which could find application in the development of in-situ and real-time nitrate sensors.
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Zhu W, Qin C, Ma H, Xi S, Zuo T, Pan W, Li C. Response of protist community dynamics and co-occurrence patterns to the construction of artificial reefs: A case study in Daya Bay, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 742:140575. [PMID: 32623178 DOI: 10.1016/j.scitotenv.2020.140575] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 06/16/2020] [Accepted: 06/26/2020] [Indexed: 05/25/2023]
Abstract
Artificial reefs (ARs) are widely used for biodiversity conservation and coastal habitat restoration. Although protists play an important ecological role in marine ecosystems, the response of the protist community to ARs is still poorly understood. In the current study, an Illumina sequencing analysis of 18S rDNA was performed, and the diversity, community structure, and co-occurrence networks of protists in the ARs and open sea area (OW) in Daya Bay were described. The results indicated that significant seasonal differences occur in the seawater protists between the surface and bottom of the ARs and OW. However, the protists in the ARs and OW had different seasonal variations. The ARs always affected the alpha diversity of marine protists in different seasons, while the surface and bottom OW sites had different seasonal effects. The ARs sites had different effects on the community composition of the surface and bottom seawater in different seasons relative to the OW sites. The linear discriminant analysis (LDA) effect size (LEfSe) method showed that 85 biomarkers mainly belonging to 11 taxa, including Bacillariophyta, Chlorophyta, and Dinophyceae, were affected by the ARs (P < 0.05, LDA > 2.0). The ARs played an important role in the seasonal changes in the protist community composition and had different effects on the dominant species of protists in the surface and bottom seawater. A redundancy analysis (RDA) significance test showed that the structure of the protist community in Daya Bay was mainly affected by environmental factors, such as seawater temperature, salinity and dissolved oxygen. Compared with the OW group, the surface and bottom layers of the ARs had more complex protist interactions or more niches. The ARs increased the degree of spatial heterogeneity, which may lead to significant niche differentiation, indicating that ARs as habitat factors affect the complexity and stability of the symbiotic network of protists. The results could provide basic data on the response of the protist community to the ARs in Daya Bay and a reference for assessments of the impact of ARs on the ecological environment.
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Affiliation(s)
- Wentao Zhu
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China; National Fishery Resources and Environment Dapeng Observation and Experimental Station, Shenzhen 518120, China; Scientific Observing and Experimental Station of South China Sea Fishery Resources & Environment, Ministry of Agriculture and Rural Affair, Guangzhou 510300, China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China; College of Marine Sciences, Shanghai Ocean University, Shanghai 201306, China
| | - Chuanxin Qin
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China; National Fishery Resources and Environment Dapeng Observation and Experimental Station, Shenzhen 518120, China; Guangdong Provincial Key Lab. of Fishery Ecology and Environment, Guangzhou 510300, China; Scientific Observing and Experimental Station of South China Sea Fishery Resources & Environment, Ministry of Agriculture and Rural Affair, Guangzhou 510300, China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China.
| | - Hongmei Ma
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China; National Fishery Resources and Environment Dapeng Observation and Experimental Station, Shenzhen 518120, China; Scientific Observing and Experimental Station of South China Sea Fishery Resources & Environment, Ministry of Agriculture and Rural Affair, Guangzhou 510300, China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China
| | - Shigai Xi
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China; National Fishery Resources and Environment Dapeng Observation and Experimental Station, Shenzhen 518120, China; Scientific Observing and Experimental Station of South China Sea Fishery Resources & Environment, Ministry of Agriculture and Rural Affair, Guangzhou 510300, China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China
| | - Tao Zuo
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China; National Fishery Resources and Environment Dapeng Observation and Experimental Station, Shenzhen 518120, China; Scientific Observing and Experimental Station of South China Sea Fishery Resources & Environment, Ministry of Agriculture and Rural Affair, Guangzhou 510300, China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China
| | - Wanni Pan
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China; National Fishery Resources and Environment Dapeng Observation and Experimental Station, Shenzhen 518120, China; Scientific Observing and Experimental Station of South China Sea Fishery Resources & Environment, Ministry of Agriculture and Rural Affair, Guangzhou 510300, China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China; College of Marine Sciences, Shanghai Ocean University, Shanghai 201306, China
| | - Chunhou Li
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China; National Fishery Resources and Environment Dapeng Observation and Experimental Station, Shenzhen 518120, China; Guangdong Provincial Key Lab. of Fishery Ecology and Environment, Guangzhou 510300, China; Scientific Observing and Experimental Station of South China Sea Fishery Resources & Environment, Ministry of Agriculture and Rural Affair, Guangzhou 510300, China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China
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Fiorendino JM, Smith JL, Campbell L. Growth response of Dinophysis, Mesodinium, and Teleaulax cultures to temperature, irradiance, and salinity. HARMFUL ALGAE 2020; 98:101896. [PMID: 33129454 DOI: 10.1016/j.hal.2020.101896] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 08/21/2020] [Accepted: 08/21/2020] [Indexed: 06/11/2023]
Abstract
Mixotrophic Dinophysis species threaten human health and coastal economies through the production of toxins which cause diarrhetic shellfish poisoning (DSP) in humans. Novel blooms of Dinophysis acuminata and Dinophysis ovum have occurred in North American waters in recent decades, resulting in the closure of shellfish harvesting. Understanding the ecology of Dinophysis species and their prey is essential to predicting and mitigating the impact of blooms of these dinoflagellates. The growth response of two new isolates of Dinophysis species, one isolate of Mesodinium rubrum, and two strains of Teleaulax amphioxeia were evaluated at a range of temperature, salinity, and irradiance treatments to identify possible environmental drivers of Dinophysis blooms in the Gulf of Mexico. Results showed optimal growth of T. amphioxeia and M. rubrum at 24 °C, salinity 30 - 34, and irradiances between 300 and 400 µmol quanta m - 2s - 1. Optimal Dinophysis growth was observed at salinity 22 and temperatures between 18 and 24 °C. Mesodinium and both Dinophysis responded differently to experimental treatments, which may be due to the suitability of prey and different handling of kleptochloroplasts. Dinophysis bloom onset may be initiated by warming surface waters between winter and spring in the Gulf of Mexico. Toxin profiles for these two North American isolates were distinct; Dinophysis acuminata produced okadaic acid, dinophysistoxin-1, and pectenotoxin-2 while D. ovum produced only okadaic acid. Toxin per cell for D. ovum was two orders of magnitude greater than D. acuminata. Phylogenies based on the cox1 and cob genes did not distinguish these two Dinophysis species within the D. acuminata complex.
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Affiliation(s)
- James M Fiorendino
- Department of Oceanography, Texas A&M University, College Station, TX 77843, USA
| | - Juliette L Smith
- Virginia Institute of Marine Science, College of William & Mary, Gloucester Point, Virginia, 23062, USA
| | - Lisa Campbell
- Department of Oceanography, Texas A&M University, College Station, TX 77843, USA.
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Gaillard S, Charrier A, Malo F, Carpentier L, Bougaran G, Hégaret H, Réveillon D, Hess P, Séchet V. Combined Effects of Temperature, Irradiance, and pH on Teleaulax amphioxeia (Cryptophyceae) Physiology and Feeding Ratio For Its Predator Mesodinium rubrum (Ciliophora) 1. JOURNAL OF PHYCOLOGY 2020; 56:775-783. [PMID: 32052865 DOI: 10.1111/jpy.12977] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 01/31/2020] [Indexed: 06/10/2023]
Abstract
The cryptophyte Teleaulax amphioxeia is a source of plastids for the ciliate Mesodinium rubrum and both organisms are members of the trophic chain of several species of Dinophysis. It is important to better understand the ecology of organisms at the first trophic levels before assessing the impact of principal factors of global change on Dinophysis spp. Therefore, combined effects of temperature, irradiance, and pH on growth rate, photosynthetic activity, and pigment content of a temperate strain of T. amphioxeia were studied using a full factorial design (central composite design 23 *) in 17 individually controlled bioreactors. The derived model predicted an optimal growth rate of T. amphioxeia at a light intensity of 400 μmol photons · m-2 · s-1 , more acidic pH (7.6) than the current average and a temperature of 17.6°C. An interaction between temperature and irradiance on growth was also found, while pH did not have any significant effect. Subsequently, to investigate potential impacts of prey quality and quantity on the physiology of the predator, M. rubrum was fed two separate prey: predator ratios with cultures of T. amphioxeia previously acclimated at two different light intensities (100 and 400 μmol photons · m-2 s-1 ). M. rubrum growth appeared to be significantly dependent on prey quantity while effect of prey quality was not observed. This multi-parametric study indicated a high potential for a significant increase of T. amphioxeia in future climate conditions but to what extent this would lead to increased occurrences of Mesodinium spp. and Dinophysis spp. should be further investigated.
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Affiliation(s)
- Sylvain Gaillard
- Laboratoire Phycotoxines, IFREMER, rue de l'Ile d'Yeu, Nantes 03, F-44311, France
| | - Aurélie Charrier
- Laboratoire Physiologie et Biotechnologie des Algues (PBA), IFREMER, rue de l'Ile d'Yeu, Nantes 03, F-44311, France
| | - Florent Malo
- Laboratoire Phycotoxines, IFREMER, rue de l'Ile d'Yeu, Nantes 03, F-44311, France
| | - Liliane Carpentier
- Laboratoire Phycotoxines, IFREMER, rue de l'Ile d'Yeu, Nantes 03, F-44311, France
| | - Gaël Bougaran
- Laboratoire Physiologie et Biotechnologie des Algues (PBA), IFREMER, rue de l'Ile d'Yeu, Nantes 03, F-44311, France
| | - Hélène Hégaret
- Laboratoire des sciences de l'environnement marin (LEMAR), IUEM-UBO, Technopôle Brest Iroise, 29280, Plouzané, France
| | - Damien Réveillon
- Laboratoire Phycotoxines, IFREMER, rue de l'Ile d'Yeu, Nantes 03, F-44311, France
| | - Philipp Hess
- Laboratoire Phycotoxines, IFREMER, rue de l'Ile d'Yeu, Nantes 03, F-44311, France
| | - Véronique Séchet
- Laboratoire Phycotoxines, IFREMER, rue de l'Ile d'Yeu, Nantes 03, F-44311, France
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Peltomaa ET, Taipale S. Osmotrophic glucose and leucine assimilation and its impact on EPA and DHA content in algae. PeerJ 2020; 8:e8363. [PMID: 31915592 PMCID: PMC6944096 DOI: 10.7717/peerj.8363] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 12/06/2019] [Indexed: 11/24/2022] Open
Abstract
The uptake of dissolved organic compounds, that is, osmotrophy, has been shown to be an efficient nutritional strategy for algae. However, this mode of nutrition may affect the biochemical composition, for example, the fatty acid (FA) contents, of algal cells. This study focused on the osmotrophic assimilation of glucose and leucine by selected seven algal strains belonging to chlorophytes, chrysophytes, cryptophytes, dinoflagellates and euglenoids. Our laboratory experiments with stable isotope labeling showed that osmotrophy occurred in four of the selected seven strains. However, only three of these produced long chain omega-3 FAs eicosapentaenoic acid (EPA; 20:5ω3) and docosahexaenoic acid (DHA; 22:6ω3). High glucose content (5 mg L-1) affected negatively on the total FAs of Mallomonas kalinae and the total omega-3 FAs of Cryptomonas sp. Further, glucose assimilation explained 35% (negative effect) and leucine assimilation 48% (positive effect) of the variation of EPA, DHA and the FAs related to their synthesis in Cryptomonas sp. Moderate glucose concentration (2 mg L-1) was found to enhance the growth of Cryptomonas ozolinii, whereas low leucine (20 µg L-1) enhanced the growth of M. kalinae. However, no systematic effect of osmotrophy on growth rates was detected. Our study shows that osmotrophic assimilation of algae is species and compound specific, and that the effects of the assimilated compounds on algal metabolism also varies depending on the species.
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Affiliation(s)
- Elina T. Peltomaa
- Faculty of Biological and Environmental Sciences, Lammi Biological Station, University of Helsinki, Lammi, Finland
| | - Sami Taipale
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
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Baek SH, Son M, Kim YO, Cho H, Chung IK, Park BS. Can algicide (the thiazolidinedione derivative TD49) truly contribute to the restoration of microbial communities? ENVIRONMENTAL RESEARCH 2019; 173:517-527. [PMID: 30986653 DOI: 10.1016/j.envres.2019.03.070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 03/28/2019] [Accepted: 03/29/2019] [Indexed: 06/09/2023]
Abstract
Harmful algal blooms (HABs) are becoming a more serious ecological threat to marine environments; they not only produce toxins, resulting in the death of marine organisms, but they also adversely affect biodiversity, which is an indicator of the health of an ecosystem. Thus, to mitigate HABs, numerous studies have been conducted to develop an effective algicide, but few studies have elucidated the effect of algicides on marine environmental health. In this study, thiazolidinedione derivative 49 (TD49), which has been developed as an algicide for the dinoflagellate Heterocapsa circularisquama, was used, and we investigated changes in phytoplankton biomass (abundance, chlorophyll a, and carbon biomass) and biodiversity (diversity, evenness, and richness) following the application of TD49. To gain deeper understanding, a large-scale mesocosm (1300 L) experiment containing control and treatment with four different concentrations (0.2, 0.4, 0.6 and 1 μM) was conducted for 10 days. Based on a previous study, TD49 shows algicidal activity against H. circularisquama depending on its concentration. The phytoplankton biomass in the TD49 treatments was generally lower than that in the control due to the algicidal effect of TD49 on H. circularisquama. The biodiversity indices (e.g., the Shannon-Weaver index) in the treatments were consistently higher than those in the control before depletion of nitrite + nitrate. Interestingly, the 0.6 μM TD49 treatment had higher biodiversity indices than the high-concentration treatment (1 μM), which appeared to show a better algicidal effect. These findings suggest that mitigation of H. circularisquama blooms with TD49 treatment may enhance phytoplankton biodiversity, but treatment with excessively high concentrations can lead to harmful effects. During the study period, regardless of the control and TD49 treatments, the total biomass of phytoplankton gradually decreased from the midpoint of the experiment to the end of the experiment. This was more likely caused by the depletion of nutrients than by the toxicity of TD49.
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Affiliation(s)
- Seung Ho Baek
- South Sea Research Institute, Korea Institute of Ocean Science and Technology (KIOST), Geoje, 53201, South Korea
| | - Moonho Son
- South Sea Research Institute, Korea Institute of Ocean Science and Technology (KIOST), Geoje, 53201, South Korea; National Institute of Fisheries Science/South Sea Fisheries Research Institute, Yeosu, 59780, South Korea.
| | - Young Ok Kim
- Marine Environmental &Climate Research Division, Korea Institute of Ocean Science & Technology, Busan, 49111, South Korea
| | - Hoon Cho
- Department of Environmental Engineering, Pioneer Research Center for Controlling of Harmful Algal Bloom, Chosun University, Gwangju, 61452, South Korea
| | - Ik Kyo Chung
- Department of Oceanography, Pusan National University, Busan, 46241, South Korea
| | - Bum Soo Park
- Marine Ecosystem Research Center, Korea Institute of Ocean Science & Technology, Busan 49111, South Korea; Marine Science Institute, University of Texas at Austin, Port Aransas, TX 78373, USA.
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Cabrerizo MJ, González-Olalla JM, Hinojosa-López VJ, Peralta-Cornejo FJ, Carrillo P. A shifting balance: responses of mixotrophic marine algae to cooling and warming under UVR. THE NEW PHYTOLOGIST 2019; 221:1317-1327. [PMID: 30306559 DOI: 10.1111/nph.15470] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 09/03/2018] [Indexed: 06/08/2023]
Abstract
Mixotrophy is a dominant metabolic strategy in ecosystems worldwide. Shifts in temperature (T) and light (i.e. the ultraviolet portion of spectrum (UVR)) are key abiotic factors that modulate the conditions under which an organism is able to live. However, whether the interaction between both drivers alters mixotrophy in a global-change context remains unassessed. To determine the T × UVR effects on relative electron transport rates, nonphotochemical quenching, bacterivory, and bacterial production, we conducted an experiment with Isochrysis galbana populations grown mixotrophically, which were exposed to 5°C of cooling and warming with respect to the control (19°C) with (or without) UVR over light-dark cycles and different timescales. At the beginning of the experiment, cooling inhibited the relative electron transport and bacterivory rates, whereas warming depressed only bacterivory regardless of the radiation treatment. By the end of the experiment, warming and UVR conditions stimulated bacterivory. These reduced relative electron transport rates (c. 50% (warming) and > 70% (cooling)) were offset by increased (35%) cumulative bacterivory rates under warming and UVR conditions. We propose that mixotrophy constitutes an energy-saving and a compensatory mechanism to gain carbon (C) when photosynthesis is impaired, and highlight the need to consider the natural environmental changes affecting the populations when we test the impacts of interacting global-change drivers.
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Affiliation(s)
- Marco J Cabrerizo
- Departamento de Ecología, Facultad de Ciencias, Universidad de Granada, Campus Fuentenueva s/n, Granada, 18071, España
- Instituto Universitario de Investigación del Agua, Universidad de Granada, C/Ramón y Cajal, 4, Granada, 18071, España
| | - Juan Manuel González-Olalla
- Departamento de Ecología, Facultad de Ciencias, Universidad de Granada, Campus Fuentenueva s/n, Granada, 18071, España
- Instituto Universitario de Investigación del Agua, Universidad de Granada, C/Ramón y Cajal, 4, Granada, 18071, España
| | - Víctor J Hinojosa-López
- Instituto Universitario de Investigación del Agua, Universidad de Granada, C/Ramón y Cajal, 4, Granada, 18071, España
| | - Francisco J Peralta-Cornejo
- Instituto Universitario de Investigación del Agua, Universidad de Granada, C/Ramón y Cajal, 4, Granada, 18071, España
| | - Presentación Carrillo
- Instituto Universitario de Investigación del Agua, Universidad de Granada, C/Ramón y Cajal, 4, Granada, 18071, España
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Anderson R, Charvet S, Hansen PJ. Mixotrophy in Chlorophytes and Haptophytes-Effect of Irradiance, Macronutrient, Micronutrient and Vitamin Limitation. Front Microbiol 2018; 9:1704. [PMID: 30108563 PMCID: PMC6080504 DOI: 10.3389/fmicb.2018.01704] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 07/09/2018] [Indexed: 01/16/2023] Open
Abstract
Chlorophytes and haptophytes are key contributors to global phytoplankton biomass and productivity. Mixotrophic bacterivory has been detected for both groups, but a shortage of studies with cultured representatives hinders a consistent picture of the ecological relevance and regulation of this trophic strategy. Here, the growth, primary production, fraction of feeding cells (acidotropic probes) and bacterivory rates (surrogate prey) are tested for two species of the chlorophyte genus Nephroselmis and the haptophyte Isochrysis galbana under contrasting regimes of light (high vs. low) and nutrients (non-limited and macronutrient-, micronutrient- and vitamin-limited), at low bacterial concentrations (<107 bacteria mL-1). All three species were obligate phototrophs, unable to compensate for low light conditions through feeding. Under nutrient limitation, N. rotunda and I. galbana fed, but growth ceased or was significantly lower than in the control. Thus, mixotrophic bacterivory could be a survival rather than a growth strategy for certain species. In contrast, nutrient-limited N. pyriformis achieved growth rates equivalent to the control through feeding. This strikingly differs with the classical view of chlorophytes as primarily non-feeders and indicates mixotrophic bacterivory can be a significant trophic strategy for green algae, even at the low bacterial concentrations found in oligotrophic open oceans.
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Affiliation(s)
- Ruth Anderson
- Marine Biology Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Sophie Charvet
- Leibniz Institute for Baltic Sea Research Warnemuende, Rostock, Germany.,Biology and Paleo Environment, Lamont-Doherty Earth Observatory, Columbia University, New York, NY, United States
| | - Per J Hansen
- Marine Biology Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
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Yoo YD, Seong KA, Kim HS, Jeong HJ, Yoon EY, Park J, Kim JI, Shin W, Palenik B. Feeding and grazing impact by the bloom-forming euglenophyte Eutreptiella eupharyngea on marine eubacteria and cyanobacteria. HARMFUL ALGAE 2018; 73:98-109. [PMID: 29602510 DOI: 10.1016/j.hal.2018.02.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Revised: 12/19/2017] [Accepted: 02/12/2018] [Indexed: 06/08/2023]
Abstract
The phototrophic euglenophyte Eutreptiella eupharyngea often causes blooms in the coastal waters of many countries, but its mode of nutrition has not been assessed. This species has previously been considered as exclusively auxotrophic. To explore whether E. eupharyngea is a mixotrophic species, the protoplasm of E. eupharyngea cells were examined using light, epifluorescence, and transmission electron microscopy after eubacteria, the cyanobacterium Synechococcus sp., and diverse algal species were provided as potential prey. Furthermore, the ingestion rates of E. eupharyngea KR on eubacteria or Synechococcus sp. as a function of prey concentration were measured. In addition, grazing by natural populations of euglenophytes on natural populations of eubacteria in Masan Bay was investigated. This study is the first to report that E. eupharyngea is a mixotrophic species. Among the potential prey organisms offered, E. eupharyngea fed only on eubacteria and Synechococcus sp., and the maximum ingestion rates of these two organisms measured in the laboratory were 5.7 and 0.7 cells predator-1 h-1, respectively. During the field experiments, the maximum ingestion rates and grazing impacts of euglenophytes, including E. eupharyngea, on natural populations of eubacteria were 11.8 cells predator-1 h-1 and 1.228 d-1, respectively. Therefore, euglenophytes could potentially have a considerable grazing impact on marine bacterial populations.
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Affiliation(s)
- Yeong Du Yoo
- Department of Marine Biotechnology, College of Ocean Science and Technology, Kunsan National University, Kunsan, 54150, Republic of Korea.
| | - Kyeong Ah Seong
- Department of Marine Biotechnology, College of Ocean Science and Technology, Kunsan National University, Kunsan, 54150, Republic of Korea
| | - Hyung Seop Kim
- Department of Marine Biotechnology, College of Ocean Science and Technology, Kunsan National University, Kunsan, 54150, Republic of Korea
| | - Hae Jin Jeong
- School of Earth and Environmental Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea; Environment and Resource Convergence Center, Advanced Institutes of Convergence Technology, Suwon 16229, Republic of Korea.
| | - Eun Young Yoon
- Environment and Resource Convergence Center, Advanced Institutes of Convergence Technology, Suwon 16229, Republic of Korea
| | - Jaeyeon Park
- Environment and Resource Convergence Center, Advanced Institutes of Convergence Technology, Suwon 16229, Republic of Korea
| | - Jong Im Kim
- Department of Biology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Woongghi Shin
- Department of Biology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Brian Palenik
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA 92093-0202, USA
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