@article {vazquez_high-co2_2022, title = {High-CO2 Levels Rather than Acidification Restrict Emiliania huxleyi Growth and Performance}, journal = {Microbial Ecology}, year = {2022}, abstract = {The coccolithophore Emiliania huxleyi shows a variety of responses to ocean acidification (OA) and to high-CO2 concentrations, but there is still controversy on differentiating between these two factors when using different strains and culture methods. A heavily calcified type A strain isolated from the Norwegian Sea was selected and batch cultured in order to understand whether acclimation to OA was mediated mainly by CO2 or H+, and how it impacted cell growth performance, calcification, and physiological stress management. Emiliania huxleyi responded differently to each acidification method. CO2-enriched aeration (1200 {\textmu}atm, pH 7.62) induced a negative effect on the cells when compared to acidification caused by decreasing pH alone (pH 7.60). The growth rates of the coccolithophore were more negatively affected by high pCO2 than by low pH without CO2 enrichment with respect to the control (400 {\textmu}atm, pH 8.1). High CO2 also affected cell viability and promoted the accumulation of reactive oxygen species (ROS), which was not observed under low pH. This suggests a possible metabolic imbalance induced by high CO2 alone. In contrast, the affinity for carbon uptake was negatively affected by both low pH and high CO2. Photochemistry was only marginally affected by either acidification method when analysed by PAM fluorometry. The POC and PIC cellular quotas and the PIC:POC ratio shifted along the different phases of the cultures; consequently, calcification did not follow the same pattern observed in cell stress and growth performance. Specifically, acidification by HCl addition caused a higher proportion of severely deformed coccoliths, than CO2 enrichment. These results highlight the capacity of CO2 rather than acidification itself to generate metabolic stress, not reducing calcification.}, keywords = {Calcification, coccolithophores, Emiliania huxleyi, Ocean acidification, pCO2, Photochemistry, phytoplankton, rcc1226, Stress}, issn = {1432-184X}, doi = {10.1007/s00248-022-02035-3}, url = {https://doi.org/10.1007/s00248-022-02035-3}, author = {V{\'a}zquez, V{\'\i}ctor and Le{\'o}n, Pablo and Gordillo, Francisco J. L. and Jim{\'e}nez, Carlos and Concepci{\'o}n, I{\~n}iguez and Mackenzie, Kevin and Bresnan, Eileen and Segovia, Mar{\'\i}a} } @article {fernandes_high-value_2022, title = {High-value lipids accumulation by Pavlova pinguis as a response to nitrogen-induced changes}, journal = {Biomass and Bioenergy}, volume = {158}, year = {2022}, month = {mar}, pages = {106341}, abstract = {The challenges of exploring the potential of microalgal strains for biotechnological applications include the optimization of their cell growth and chemical composition. To overcome this, it is essential to understand the mechanisms that lead to the accumulation of desired products within microalgal cells. In this study, a gradient of nitrogen as nitrate (NO3{\textendash}N) concentrations was used for the preparation of P. pinguis growth medium. The algal growth dynamics, pigments, nutrient uptake, and detailed lipid composition across treatments were assessed. Increasing the NO3{\textendash}N level led to higher lipid content (21\%), a higher cell uptake rate (0.20 pg NO3{\textendash}N cell-1 d-1) and more accumulation of chlorophylls, carotenoids, and high-value lipids. Eicosapentaenoic acid, essential fatty acids, phytol and stigmasterol were the key high-value lipids that were positively influenced by higher NO3{\textendash}N levels. High NO3{\textendash}N conditions induced an increase of 54\% in total sterol content, while low NO3{\textendash}N conditions resulted in increased proportions of saturated fatty acids (66\% more) and decreased proportions of polyunsaturated fatty acids (14\% less). The low NO3{\textendash}N level also led to higher amounts of monoglyceride (1.60 mg g-1; 64\% more). The analysis of P. pinguis lipids before and after hydrolysis provided an insight into the composition of the esterified lipids across treatments. NO3{\textendash}N supplementation was revealed to be an effective strategy for enhancing P. pinguis lipid composition, for nutraceutical and pharmaceutical industries (high NO3{\textendash}N level). A greater understanding of the NO3{\textendash}N uptake and the use efficiency by P. pinguis was reached, showing its potential for further biotechnological applications.}, keywords = {Biotechnological application, High-value lipids, RCC1359, supply}, issn = {0961-9534}, doi = {10.1016/j.biombioe.2022.106341}, url = {https://www.sciencedirect.com/science/article/pii/S0961953422000022}, author = {Fernandes, Tom{\'a}sia and Cordeiro, Nereida} } @article {Magalhaes2018, title = {Hemiselmis aquamarina sp . nov . (Cryptomonadales , Cryptophyceae), a cryptomonad with a novel phycobiliprotein type (Cr-PC 564)}, journal = {Protist}, volume = {in press}, year = {2021}, keywords = {RCC4102, RCC5634, to add}, doi = {10.1016/j.protis.2021.125832}, url = {https://doi.org/10.1016/j.protis.2021.125832}, author = {Magalh{\~a}es, Karoline and Lopes dos Santos, Adriana and Vaulot, Daniel and de Oliveira, Mariana Cabral} } @article {Fernandes2020, title = {Hemiselmis andersenii and chlorella stigmatophora as new sources of High-value compounds: A lipidomic approach}, journal = {Journal of Phycology}, year = {2020}, note = {Publisher: Blackwell Publishing Inc. tex.mendeley-tags: RCC661}, month = {aug}, pages = {jpy.13042}, abstract = {To unlock the potential of Chlorella stigmatophora (Trebouxiophyceae, Chlorophyta) and Hemiselmis andersenii (Cryptophyceae, Cryptophyta) as natural reactors for biotechnological exploitation, their lipophilic extracts were characterized using Fourier Transform Infrared spectroscopy with Attenuated Total Reflectance (FTIR-ATR) and Gas Chromatography-Mass Spectrometry (GC-MS) before and after alkaline hydrolysis. The GC-MS analysis enabled the identification of 62 metabolites{\textemdash}namely fatty acids (27), aliphatic alcohols (17), monoglycerides (7), sterols (4), and other compounds (7). After alkaline hydrolysis, monounsaturated fatty acids increased by as much as 87\%, suggesting that the esterified compounds were mainly neutral lipids. Hemiselmis andersenii yielded the highest Σω3/Σω6 ratio (7.26), indicating that it is a good source of ω3 fatty acids, in comparison to C. stigmatophora (Σω3/Σω6 = 1.24). Both microalgae presented significant amounts of aliphatic alcohols (6.81{\textendash}10.95 mg ? g dw-1), which are recognized by their cholesterol-lowering properties. The multivariate analysis allowed visualization of the chemical divergence among H. andersenii lipophilic extracts before and after alkaline hydrolysis, as well as species-specific differences. Chlorella stigmatophora showed to be a valuable source of essential fatty acids for nutraceuticals, whereas H. andersenii, due to its high chemical diversity, seems to be suitable for different fields of application.}, keywords = {Chlorella stigmatophora, GC-MS, Hemiselmis andersenii, lipophilic fraction, Microalgae, RCC661}, issn = {0022-3646}, doi = {10.1111/jpy.13042}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/jpy.13042}, author = {Fernandes, Tom{\'a}sia and Cordeiro, Nereida}, editor = {Li, Y.} } @article {bottini_high_2020, title = {High resolution spatial analyses of trace elements in coccoliths reveal new insights into element incorporation in coccolithophore calcite}, journal = {Scientific Reports}, volume = {10}, number = {1}, year = {2020}, note = {Number: 1 Publisher: Nature Publishing Group}, pages = {9825}, abstract = {Coccolithophores are phytoplanktonic algae which produce an exoskeleton made of single platelets of calcite named coccoliths. They are widespread in all oceans and directly impact the short- and long-term C cycle. The study of coccolith size, morphology and elemental composition reveals important information regarding the ability of the cell to calcify and on the factors that influence this process. In this regard, very little is known about coccolith composition and its changes under altered environmental conditions. Here, we present high resolution (50 {\texttimes} 50 nm) elemental spatial distribution in pristine coccoliths of Coccolithus pelagicus and Gephyrocapsa oceanica reconstructed via X-ray fluorescence analyses at synchrotron. The studied specimens are from control culture and metal-enriched (V, Ni, Zn and Pb) experiments. The analysed specimens produced under stress conditions, display an irregular shape and are thinner, especially in the external rim, with ca. 1/3 lower Ca concentrations compared to specimens from the control. The same specimens also have higher Sr/Ca ratio with highest values in the coccolith external rim, suggesting that difficulty in calcification is additionally reflected in increased Sr/Ca ratios. Selenium is found in the coccolith as possible substitute of carbonate in the calcite. V and Pb apparently did not interact with the coccoliths while Zn and Ni were deposited on the coccolith surface.}, keywords = {Environmental chemistry, Environmental impact, Marine chemistry, Pollution remediation, RCC1198, RCC1303}, issn = {2045-2322}, doi = {10.1038/s41598-020-66503-x}, url = {http://www.nature.com/articles/s41598-020-66503-x}, author = {Bottini, Cinzia and Dapiaggi, Monica and Erba, Elisabetta and Faucher, Giulia and Rotiroti, Nicola} } @article {Weiss2019, title = {Hydrogen isotope fractionation response to salinity and alkalinity in a calcifying strain of Emiliania huxleyi}, journal = {Organic Geochemistry}, year = {2019}, note = {Publisher: Elsevier Ltd tex.mendeley-tags: RCC2050}, month = {jun}, keywords = {RCC2050}, issn = {01466380}, doi = {10.1016/j.orggeochem.2019.06.001}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0146638019301020}, author = {Weiss, Gabriella M. and Roepert, Anne and Middelburg, Jack J. and Schouten, Stefan and Sinninghe Damst{\'e}, Jaap S. and van der Meer, Marcel T.J.} } @article {Garcia2018, title = {High variability in cellular stoichiometry of carbon, nitrogen, and phosphorus within classes of marine eukaryotic phytoplankton under sufficient nutrient conditions}, journal = {Frontiers in Microbiology}, volume = {9}, number = {March}, year = {2018}, note = {tex.mendeley-tags: RCC103,RCC1242,RCC1562,RCC4023,RCC449,RCC931}, pages = {1{\textendash}10}, abstract = {Current hypotheses suggest that cellular elemental stoichiometry of marine eukaryotic phytoplankton such as the ratios of cellular carbon:nitrogen:phosphorus (C:N:P) vary between phylogenetic groups based traits like evolutionary history and cell size. To investigate how phylogenetic structure, cell volume, growth rate and temperature interact to affect the cellular elemental stoichiometry of marine eukaryotic phytoplankton, we examined the C:N:P composition in 30 isolates across 7 classes of marine phytoplankton that were grown with a sufficient supply of nutrients with nitrate as the nitrogen source. The isolates covered a wide range in cell volume (5 orders of magnitude), growth rate ({\textexclamdown}0.01-0.9 d-1), and habitat temperature (2-24{\textdegree}C). Our analysis indicates that C:N:P is highly variable, with statistical model residuals accounting for over half of the total variance with no relationship between phylogeny and elemental stoichiometry. Furthermore, our data indicated that variability in C:P, N:P and C:N within Bacillariophyceae (diatoms) was as high as that among all of the isolates that we examined. In addition, a linear statistical model identified a positive relationship between diatom cell volume and C:P and N:P. Among all of the isolates that we examined, the statistical model identified temperature as a significant factor, consistent with the temperature-dependent translation efficiency model, but temperature only explained 5\% of the total statistical model variance. While some of our results support data from previous field studies, the high variability of elemental ratios within Bacillariophyceae contradicts previous work that suggests that this cosmopolitan group of microalgae has consistently low C:P and N:P ratios in comparison with other groups.}, keywords = {cell size, Diatom, Dinoflagellate, eukaryote, frontiers in microbiology, frontiersin, Growth, org, protist, prymnesiophyte, RCC103, RCC1242, RCC1562, RCC4023, RCC449, RCC931, temperature, www}, issn = {1664-302X}, doi = {10.3389/fmicb.2018.00543}, url = {http://journal.frontiersin.org/article/10.3389/fmicb.2018.00543/full}, author = {Garcia, Nathan S. and Sexton, Julie and Riggins, Tracey and Brown, Jeff and Lomas, Michael W. and Martiny, Adam C.} } @article {Monier2017, title = {Host-derived viral transporter protein for nitrogen uptake in infected marine phytoplankton}, journal = {Proceedings of the National Academy of Sciences}, year = {2017}, note = {tex.mendeley-tags: RCC1107,RCC1621,RCC2573,RCC2593,RCC745,RCC809}, pages = {201708097}, keywords = {rcc1107, RCC1621, RCC2573, RCC2593, RCC745, RCC809}, issn = {0027-8424}, doi = {10.1073/pnas.1708097114}, url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1708097114}, author = {Monier, Adam and Chambouvet, Aurelie and Milner, David S. and Attah, Victoria and Terrado, Ram{\'o}n and Lovejoy, Connie and Moreau, Herv{\'e} and Santoro, Alyson E. and Derelle, Evelyne and Richards, Thomas A.} } @article {Klouch2016, title = {Historical records from dated sediment cores reveal the multidecadal dynamic of the toxic dinoflagellate Alexandrium minutum in the Bay of Brest (France)}, journal = {FEMS Microbiology Ecology}, volume = {92}, number = {7}, year = {2016}, note = {tex.mendeley-tags: 2016,rcc,sbr?hyto$_\textrmd$ipo}, month = {jul}, pages = {fiw101}, abstract = {The multiannual dynamic of the cyst-forming and toxic marine dinoflagellate Alexandrium minutum was studied over a time scale of about 150 years by a paleoecological approach based on ancient DNA (aDNA) quantification and cyst revivification data obtained from two dated sediment cores of the Bay of Brest (Brittany, France). The first genetic traces of the species presence in the study area dated back to 1873 {\textpm} 6. Specific aDNA could be quantified by a newly-developed real-time PCR assay in the upper core layers, in which the germination of the species (in up to 17-19 year-old sediments) was also obtained. In both cores studied, our quantitative paleogenetic data showed a statistically significant increasing trend in the abundance of A. minutum ITS1 rDNA copies over time, corroborating three decades of local plankton data that have documented an increasing trend in the species cell abundance. By comparison, paleogenetic data of the dinoflagellate Scrippsiella donghaienis did not show a coherent trend between the cores studied, supporting the hypothesis of the existence of a species-specific dynamic of A. minutum in the study area. This work contributes to the development of paleoecological research, further showing its potential for biogeographical, ecological and evolutionary studies on marine microbes.}, keywords = {2016, rcc, sbr?hyto$_\textrmd$ipo}, issn = {1574-6941}, doi = {10.1093/femsec/fiw101}, url = {http://www.ncbi.nlm.nih.gov/pubmed/27162179 https://academic.oup.com/femsec/article-lookup/doi/10.1093/femsec/fiw101}, author = {Klouch, Khadidja Z and Schmidt, Sabine and Andrieux-Loyer, Fran{\c c}oise and Le Gac, Micka{\"e}l and Hervio-Heath, Dominique and Qui-Minet, Zujaila N and Qu{\'e}r{\'e}, Julien and Bigeard, Estelle and Guillou, Laure and Siano, Raffaele}, editor = {Laanbroek, Riks} } @article {Monier2009, title = {Horizontal gene transfer of an entire metabolic pathway between a eukaryotic alga and its DNA virus}, journal = {Genome Research}, volume = {19}, year = {2009}, note = {tex.mendeley-tags: 2009,rcc,sbr?hyto?ppo}, pages = {1441{\textendash}1449}, keywords = {2009, rcc, SBR$_\textrmP$hyto$_\textrmE$PPO, sbr?hyto?ppo}, doi = {10.1101/gr.091686.109}, author = {Monier, A and Pagarete, A and Allen, M J and Read, B A and de Vargas, C and Claverie, J M and Ogata, H} } @article {Scanlan1996, title = {High degree of genetic variation in Prochlorococcus (Prochlorophyta) revealed by RFLP analysis}, journal = {European Journal of Phycology}, volume = {31}, number = {1}, year = {1996}, note = {tex.mendeley-tags: RCC,rcc}, pages = {1{\textendash}9}, keywords = {DIVINYL CHLOROPHYLL-A, FAMILY, Marine Synechococcus, Mediterranean Sea, Multiple Evolutionary Origins, north-atlantic, NUCLEOTIDE-SEQUENCE, picoplankton, Prokaryote, rcc, RCC SBR$_\textrmP$hyto, UNICELLULAR CYANOBACTERIUM}, doi = {10.1080/09670269600651131}, author = {Scanlan, D J and Hess, W R and Partensky, F and Newman, J and Vaulot, D} }