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Primary consumers in freshwater ecosystems, such as the zooplankton organism Daphnia magna, are highly affected by cyanobacteria, both as they may use it as a food source but also by cyanobacterial metabolites present in the water. Here, we investigate the impacts of cyanobacterial metabolites focussing on the environmental realistic scenario of the naturally released mixture without crushing cyanobacterial cells or their uptake as food. Therefore, D. magna were exposed to two concentrations of cell free cyanobacterial spent medium from Microcystis aeruginosa PCC 7806 to represent higher and lower ecologically-relevant concentrations of cyanobacterial metabolites. Including microcystin-LR, 11 metabolites have been detected of which 5 were quantified. Hypothesising concentration and time dependent negative impact, survival, gene expression marking digestion and metabolism, oxidative stress response, cell cycle and molting as well as activities of detoxification and antioxidant enzymes were followed for 7 days. D. magna suffered from oxidative stress as both catalase and glutathione S-transferase enzyme activities significantly decreased, suggesting enzyme exhaustibility after 3 and 7 days. Moreover, gene-expressions of the 4 stress markers (glutathione S-transferase, glutathione peroxidase, catalase and thioredoxin) were merely downregulated after 7 days of exposure. Energy allocation (expression of glyceraldehyde-3-phosphate dehydrogenase) was increased after 3 days but decreased as well after 7 days exposure. Cell cycle was impacted time dependently but differently by the two concentrations, along with an increasing downregulation of myosin heavy chain responsible for cell arrangement and muscular movements. Deregulation of nuclear hormone receptor genes indicate that D. magna hormonal steering including molting seemed impaired despite no detection of microviridin J in the extracts. As a consequence of all those responses and presumably of more than investigated molecular and physiological changes, D. magna survival was impaired over time, in a concentration dependent manner. Our results confirm that besides microcystin-LR, other secondary metabolites contribute to negative impact on D. magna survival and stress response.
Gorenka Bojadzija Savic; Hervé Colinet; Myriam Bormans; Christine Edwards; Linda A. Lawton; Enora Briand; Claudia Wiegand. Cell free Microcystis aeruginosa spent medium affects Daphnia magna survival and stress response. Toxicon 2021, 195, 37 -47.
AMA StyleGorenka Bojadzija Savic, Hervé Colinet, Myriam Bormans, Christine Edwards, Linda A. Lawton, Enora Briand, Claudia Wiegand. Cell free Microcystis aeruginosa spent medium affects Daphnia magna survival and stress response. Toxicon. 2021; 195 ():37-47.
Chicago/Turabian StyleGorenka Bojadzija Savic; Hervé Colinet; Myriam Bormans; Christine Edwards; Linda A. Lawton; Enora Briand; Claudia Wiegand. 2021. "Cell free Microcystis aeruginosa spent medium affects Daphnia magna survival and stress response." Toxicon 195, no. : 37-47.
Due to eutrophication, freshwater ecosystems frequently experience cyanobacterial blooms, many of which produce bioactive metabolites that can affect vertebrates and invertebrates life traits. Zooplankton are able to develop tolerance as a physiological response to cyanobacteria and their bioactive compounds, however, this comes with energetic cost that in turn influence Daphnia life traits and may impair populations. Vice versa, it has been suggested that Daphnia are able to reduce cyanobacterial dominance until a certain cyanobacterial density; it remains unclear whether Daphnia metabolites alone influence the physiological state and bioactive metabolites production of cyanobacteria. Hence, this study investigates mutual physiological reactions of toxic Microcystis aeruginosa PCC7806 and Daphnia magna. We hypothesize that a) the presence of D. magna will negatively affect growth, increase stress response and metabolites production in M. aeruginosa PCC7806 and b) the presence of M. aeruginosa PCC7806 will negatively affect physiological responses and life traits in D. magna. In order to test these hypotheses experiments were conducted in a specially designed co-culture chamber that allows exchange of the metabolites without direct contact. A clear mutual impact was evidenced. Cyanobacterial metabolites reduced survival of D. magna and decreased oxidative stress enzyme activity. Simultaneously, presence of D. magna did not affect photosynthetic activity. However, ROS increase and tendencies in cell density decrease were observed on the same day, suggesting possible energy allocation towards anti-oxidative stress enzymes, or other protection mechanisms against Daphnia infochemicals, as the strain managed to recover. Elevated concentration of intracellular and overall extracellular microcystin MC-LR, as well as intracellular concentrations of aerucyclamide A and D in the presence of Daphnia, indicating a potential protective or anti-grazing function. However, more research is needed to confirm these findings.
Gorenka Bojadzija Savic; Myriam Bormans; Christine Edwards; Linda Lawton; Enora Briand; Claudia Wiegand. Cross talk: Two way allelopathic interactions between toxic Microcystis and Daphnia. Harmful Algae 2020, 94, 101803 .
AMA StyleGorenka Bojadzija Savic, Myriam Bormans, Christine Edwards, Linda Lawton, Enora Briand, Claudia Wiegand. Cross talk: Two way allelopathic interactions between toxic Microcystis and Daphnia. Harmful Algae. 2020; 94 ():101803.
Chicago/Turabian StyleGorenka Bojadzija Savic; Myriam Bormans; Christine Edwards; Linda Lawton; Enora Briand; Claudia Wiegand. 2020. "Cross talk: Two way allelopathic interactions between toxic Microcystis and Daphnia." Harmful Algae 94, no. : 101803.
The transfer of Microcystis aeruginosa from freshwater to estuaries has been described worldwide and salinity is reported as the main factor controlling the expansion of M. aeruginosa to coastal environments. Analyzing the expression levels of targeted genes and employing both targeted and non-targeted metabolomic approaches, this study investigated the effect of a sudden salt increase on the physiological and metabolic responses of two toxic M. aeruginosa strains separately isolated from fresh and brackish waters, respectively, PCC 7820 and 7806. Supported by differences in gene expressions and metabolic profiles, salt tolerance was found to be strain specific. An increase in salinity decreased the growth of M. aeruginosa with a lesser impact on the brackish strain. The production of intracellular microcystin variants in response to salt stress correlated well to the growth rate for both strains. Furthermore, the release of microcystins into the surrounding medium only occurred at the highest salinity treatment when cell lysis occurred. This study suggests that the physiological responses of M. aeruginosa involve the accumulation of common metabolites but that the intraspecific salt tolerance is based on the accumulation of specific metabolites. While one of these was determined to be sucrose, many others remain to be identified. Taken together, these results provide evidence that M. aeruginosa is relatively salt tolerant in the mesohaline zone and microcystin (MC) release only occurs when the capacity of the cells to deal with salt increase is exceeded.
Maxime Georges Des Aulnois; Damien Réveillon; Elise Robert; Amandine Caruana; Enora Briand; Arthur Guljamow; Elke Dittmann; Zouher Amzil; Myriam Bormans. Salt Shock Responses of Microcystis Revealed through Physiological, Transcript, and Metabolomic Analyses. Toxins 2020, 12, 192 .
AMA StyleMaxime Georges Des Aulnois, Damien Réveillon, Elise Robert, Amandine Caruana, Enora Briand, Arthur Guljamow, Elke Dittmann, Zouher Amzil, Myriam Bormans. Salt Shock Responses of Microcystis Revealed through Physiological, Transcript, and Metabolomic Analyses. Toxins. 2020; 12 (3):192.
Chicago/Turabian StyleMaxime Georges Des Aulnois; Damien Réveillon; Elise Robert; Amandine Caruana; Enora Briand; Arthur Guljamow; Elke Dittmann; Zouher Amzil; Myriam Bormans. 2020. "Salt Shock Responses of Microcystis Revealed through Physiological, Transcript, and Metabolomic Analyses." Toxins 12, no. 3: 192.
Host-microbe interactions play crucial roles in marine ecosystems, but we still have very little understanding of the mechanisms that govern these relationships, the evolutionary processes that shape them, and their ecological consequences. The holobiont concept is a renewed paradigm in biology that can help to describe and understand these complex systems. It posits that a host and its associated microbiota, living together in a stable relationship, form the holobiont, and have to be studied together as a coherent biological and functional unit to understand its biology, ecology, and evolution. Here we discuss critical concepts and opportunities in marine holobiont research and identify key challenges in the field. We highlight the potential economic, sociological, and environmental impacts of the holobiont concept in marine biological, evolutionary, and environmental sciences with comparisons to terrestrial sciences where appropriate. Given the connectivity and the unexplored biodiversity specific to marine ecosystems, a deeper understanding of such complex systems requires further technological and conceptual advances, e.g. the development of controlled experimental model systems for holobionts from all major lineages and the modeling of (info)chemical-mediated interactions between organisms. The most significant challenge is to bridge cross-disciplinary research on tractable model systems in order to address key ecological and evolutionary questions. This will be crucial to decipher the roles of marine holobionts in biogeochemical cycles, but also developing concrete applications of the holobiont concept e.g. to increase yield or disease resistance in aquacultures or to protect and restore marine ecosystems through management projects.
Simon M Dittami; Enrique Arboleda; Jean-Christophe Auguet; Arite Bigalke; Enora Briand; Paco Cardenas; Ulisse Cardini; Johan Decelle; Aschwin H Engelen; Damien Eveillard; Claire M.M. Gachon; Sarah M Griffiths; Tilmann Harder; Ehsan Kayal; Elena Kazamia; François H Lallier; Mónica Medina; Ezequiel Marzinelli; Teresa Morganti; Laura Núñez Pons; Soizic Prado; José Pintado; Mahasweta Saha; Marc-André Selosse; Derek Skillings; Willem Stock; Shinichi Sunagawa; Eve Toulza; Alexey Vorobev; Catherine Leblanc; Fabrice Not. A community perspective on the concept of marine holobionts: current status, challenges, and future directions. 2019, 1 .
AMA StyleSimon M Dittami, Enrique Arboleda, Jean-Christophe Auguet, Arite Bigalke, Enora Briand, Paco Cardenas, Ulisse Cardini, Johan Decelle, Aschwin H Engelen, Damien Eveillard, Claire M.M. Gachon, Sarah M Griffiths, Tilmann Harder, Ehsan Kayal, Elena Kazamia, François H Lallier, Mónica Medina, Ezequiel Marzinelli, Teresa Morganti, Laura Núñez Pons, Soizic Prado, José Pintado, Mahasweta Saha, Marc-André Selosse, Derek Skillings, Willem Stock, Shinichi Sunagawa, Eve Toulza, Alexey Vorobev, Catherine Leblanc, Fabrice Not. A community perspective on the concept of marine holobionts: current status, challenges, and future directions. . 2019; ():1.
Chicago/Turabian StyleSimon M Dittami; Enrique Arboleda; Jean-Christophe Auguet; Arite Bigalke; Enora Briand; Paco Cardenas; Ulisse Cardini; Johan Decelle; Aschwin H Engelen; Damien Eveillard; Claire M.M. Gachon; Sarah M Griffiths; Tilmann Harder; Ehsan Kayal; Elena Kazamia; François H Lallier; Mónica Medina; Ezequiel Marzinelli; Teresa Morganti; Laura Núñez Pons; Soizic Prado; José Pintado; Mahasweta Saha; Marc-André Selosse; Derek Skillings; Willem Stock; Shinichi Sunagawa; Eve Toulza; Alexey Vorobev; Catherine Leblanc; Fabrice Not. 2019. "A community perspective on the concept of marine holobionts: current status, challenges, and future directions." , no. : 1.
While the intracellular function of many toxic and bioactive cyanobacterial metabolites is not yet known, microcystins have been suggested to have a protective role in the cyanobacterial metabolism, giving advantage to toxic over nontoxic strains under stress conditions. The zooplankton grazer Daphnia reduce cyanobacterial dominance until a certain density, which may be supported by Daphnia exudates, affecting the cyanobacterial physiological state and metabolites' production. Therefore, we hypothesized that D. magna spent medium will impact the production of cyanobacterial bioactive metabolites and affect cyanobacterial photosynthetic activity in the nontoxic, but not the toxic strain. Microcystin (MC-LR and des-MC-LR) producing M. aeruginosa PCC7806 and its non-microcystin producing mutant were exposed to spent media of different D. magna densities and culture durations. D. magna spent medium of the highest density (200/L) cultivated for the shortest time (24 h) provoked the strongest effect. D.magna spent medium negatively impacted the photosynthetic activity of M. aeruginosa PCC7806, as well as the dynamics of intracellular and extracellular cyanobacterial metabolites, while its mutant was unaffected. In the presence of Daphnia medium, microcystin does not appear to have a protective role for the strain. On the contrary, extracellular cyanopeptolin A increased in M. aeruginosa PCC7806 although the potential anti-grazing role of this compound would require further studies.
Gorenka Bojadzija Savic; Christine Edwards; Enora Briand; Linda Lawton; Claudia Wiegand; Myriam Bormans. Daphnia magna Exudates Impact Physiological and Metabolic Changes in Microcystis aeruginosa. Toxins 2019, 11, 421 .
AMA StyleGorenka Bojadzija Savic, Christine Edwards, Enora Briand, Linda Lawton, Claudia Wiegand, Myriam Bormans. Daphnia magna Exudates Impact Physiological and Metabolic Changes in Microcystis aeruginosa. Toxins. 2019; 11 (7):421.
Chicago/Turabian StyleGorenka Bojadzija Savic; Christine Edwards; Enora Briand; Linda Lawton; Claudia Wiegand; Myriam Bormans. 2019. "Daphnia magna Exudates Impact Physiological and Metabolic Changes in Microcystis aeruginosa." Toxins 11, no. 7: 421.
Host-microbe interactions play crucial roles in marine ecosystems, but we still have very little understanding of the mechanisms that govern these relationships, the evolutionary processes that shape them, and their ecological consequences. The holobiont concept is a renewed paradigm in biology that can help describe and understand these complex systems. It posits that a host and its associated microbiota, living together in a stable relationship, form the holobiont, and have to be studied together, as a coherent biological and functional unit, to understand its biology, ecology and evolution. Here we discuss critical concepts and opportunities in marine holobiont research and identify key challenges in the field. We highlight the potential economic, sociological, and environmental impacts of the holobiont concept in marine biological, evolutionary, and environmental sciences with comparisons to terrestrial science wherever appropriate. Given the connectivity and the unexplored biodiversity of marine ecosystems, a deeper understanding of such complex systems requires further technological and conceptual advances. For the marine scientific community, the most significant challenge is to bridge functional research on tractable and original model systems and global approaches addressing ecological and evolutionary questions. This will be crucial for establishing the roles of marine holobionts in biogeochemical cycles, but also developing concrete applications of the holobiont concept in aquaculture and marine ecosystem management projects.
Simon M Dittami; Enrique Arboleda; Jean-Christophe Auguet; Arite Bigalke; Enora Briand; Paco Cárdenas; Ulisse Cardini; Johan Decelle; Aschwin H Engelen; Damien Eveillard; Claire M.M. Gachon; Sarah M Griffiths; Tilmann Harder; Ehsan Kayal; Elena Kazamia; François H Lallier; Mónica Media; Ezequiel M. Marzinelli; Teresa Morganti; Laura Núñez Pons; Soizic Prado; José Pintado; Mahasweta Saha; Marc-André Selosse; Derek Skillings; Willem Stock; Shinichi Sunagawa; Eve Toulza; Alexey Vorobev; Catherine Leblanc; Fabrice Not. A community perspective on the concept of marine holobionts: current status, challenges, and future directions. 2019, 1 .
AMA StyleSimon M Dittami, Enrique Arboleda, Jean-Christophe Auguet, Arite Bigalke, Enora Briand, Paco Cárdenas, Ulisse Cardini, Johan Decelle, Aschwin H Engelen, Damien Eveillard, Claire M.M. Gachon, Sarah M Griffiths, Tilmann Harder, Ehsan Kayal, Elena Kazamia, François H Lallier, Mónica Media, Ezequiel M. Marzinelli, Teresa Morganti, Laura Núñez Pons, Soizic Prado, José Pintado, Mahasweta Saha, Marc-André Selosse, Derek Skillings, Willem Stock, Shinichi Sunagawa, Eve Toulza, Alexey Vorobev, Catherine Leblanc, Fabrice Not. A community perspective on the concept of marine holobionts: current status, challenges, and future directions. . 2019; ():1.
Chicago/Turabian StyleSimon M Dittami; Enrique Arboleda; Jean-Christophe Auguet; Arite Bigalke; Enora Briand; Paco Cárdenas; Ulisse Cardini; Johan Decelle; Aschwin H Engelen; Damien Eveillard; Claire M.M. Gachon; Sarah M Griffiths; Tilmann Harder; Ehsan Kayal; Elena Kazamia; François H Lallier; Mónica Media; Ezequiel M. Marzinelli; Teresa Morganti; Laura Núñez Pons; Soizic Prado; José Pintado; Mahasweta Saha; Marc-André Selosse; Derek Skillings; Willem Stock; Shinichi Sunagawa; Eve Toulza; Alexey Vorobev; Catherine Leblanc; Fabrice Not. 2019. "A community perspective on the concept of marine holobionts: current status, challenges, and future directions." , no. : 1.
Host-microbe interactions play crucial roles in marine ecosystems, but we still have very little understanding of the mechanisms that govern these relationships, the evolutionary processes that shape them, and their ecological consequences. The holobiont concept is a renewed paradigm in biology that can help to describe and understand these complex systems. It posits that a host and its associated microbiota, living together in a stable relationship, form the holobiont, and have to be studied together as a coherent biological and functional unit to understand its biology, ecology, and evolution. Here we discuss critical concepts and opportunities in marine holobiont research and identify key challenges in the field. We highlight the potential economic, sociological, and environmental impacts of the holobiont concept in marine biological, evolutionary, and environmental sciences with comparisons to terrestrial sciences where appropriate. Given the connectivity and the unexplored biodiversity specific to marine ecosystems, a deeper understanding of such complex systems requires further technological and conceptual advances, e.g. the development of controlled experimental model systems for holobionts from all major lineages and the modeling of (info)chemical-mediated interactions between organisms. The most significant challenge is to bridge cross-disciplinary research on tractable model systems in order to address key ecological and evolutionary questions. This will be crucial to decipher the roles of marine holobionts in biogeochemical cycles, but also developing concrete applications of the holobiont concept e.g. to increase yield or disease resistance in aquacultures or to protect and restore marine ecosystems through management projects.
Simon M Dittami; Enrique Arboleda; Jean-Christophe Auguet; Arite Bigalke; Enora Briand; Paco Cárdenas; Ulisse Cardini; Johan Decelle; Aschwin H Engelen; Damien Eveillard; Claire M.M. Gachon; Sarah M Griffiths; Tilmann Harder; Ehsan Kayal; Elena Kazamia; François H Lallier; Mónica Medina; Ezequiel M. Marzinelli; Teresa Morganti; Laura Núñez Pons; Soizic Prado; José Pintado; Mahasweta Saha; Marc-André Selosse; Derek Skillings; Willem Stock; Shinichi Sunagawa; Eve Toulza; Alexey Vorobev; Catherine Leblanc; Fabrice Not; Mónica Media. A community perspective on the concept of marine holobionts: current status, challenges, and future directions. 2019, 1 .
AMA StyleSimon M Dittami, Enrique Arboleda, Jean-Christophe Auguet, Arite Bigalke, Enora Briand, Paco Cárdenas, Ulisse Cardini, Johan Decelle, Aschwin H Engelen, Damien Eveillard, Claire M.M. Gachon, Sarah M Griffiths, Tilmann Harder, Ehsan Kayal, Elena Kazamia, François H Lallier, Mónica Medina, Ezequiel M. Marzinelli, Teresa Morganti, Laura Núñez Pons, Soizic Prado, José Pintado, Mahasweta Saha, Marc-André Selosse, Derek Skillings, Willem Stock, Shinichi Sunagawa, Eve Toulza, Alexey Vorobev, Catherine Leblanc, Fabrice Not, Mónica Media. A community perspective on the concept of marine holobionts: current status, challenges, and future directions. . 2019; ():1.
Chicago/Turabian StyleSimon M Dittami; Enrique Arboleda; Jean-Christophe Auguet; Arite Bigalke; Enora Briand; Paco Cárdenas; Ulisse Cardini; Johan Decelle; Aschwin H Engelen; Damien Eveillard; Claire M.M. Gachon; Sarah M Griffiths; Tilmann Harder; Ehsan Kayal; Elena Kazamia; François H Lallier; Mónica Medina; Ezequiel M. Marzinelli; Teresa Morganti; Laura Núñez Pons; Soizic Prado; José Pintado; Mahasweta Saha; Marc-André Selosse; Derek Skillings; Willem Stock; Shinichi Sunagawa; Eve Toulza; Alexey Vorobev; Catherine Leblanc; Fabrice Not; Mónica Media. 2019. "A community perspective on the concept of marine holobionts: current status, challenges, and future directions." , no. : 1.
The cyanobacterial genus Microcystis is known to produce an elaborate array of structurally unique and biologically active natural products including hazardous cyanotoxins. Cytotoxic aeruginoguanidines represent a yet unexplored family of peptides featuring a trisubstituted benzene unit and farnesylated arginine derivatives. In this study, we aimed at assigning these compounds to a biosynthetic gene cluster by utilizing biosynthetic attributes deduced from public genomes of Microcystis and the sporadic distribution of the metabolite in axenic strains of the Pasteur Culture Collection of Cyanobacteria. By integrating genome mining with untargeted metabolomics using liquid chromatography with mass spectrometry, we could link aeruginoguanidine (AGD) to a nonribosomal peptide synthetase gene cluster and co-assign a significantly smaller product to this pathway, microguanidine (MGD), previously only reported from two Microcystis blooms. Further, a new intermediate class of compounds named microguanidine amides was uncovered thereby further enlarging this compound family. The comparison of structurally divergent AGDs and MGDs reveals an outstanding versatility of this biosynthetic pathway and provides insights into the assembly of the two compound subfamilies. Strikingly, aeruginoguanidines and microguanidines were found to be as widespread as the hepatotoxic microcystins, but the occurrence of both toxin families appeared to be mutually exclusive.
Claire Pancrace; Keishi Ishida; Enora Briand; Douglas Gatte Pichi; Annika R. Weiz; Arthur Guljamow; Thibault Scalvenzi; Nathalie Sassoon; Christian Hertweck; Elke Dittmann; Muriel Gugger. Unique Biosynthetic Pathway in Bloom-Forming Cyanobacterial Genus Microcystis Jointly Assembles Cytotoxic Aeruginoguanidines and Microguanidines. ACS Chemical Biology 2018, 14, 67 -75.
AMA StyleClaire Pancrace, Keishi Ishida, Enora Briand, Douglas Gatte Pichi, Annika R. Weiz, Arthur Guljamow, Thibault Scalvenzi, Nathalie Sassoon, Christian Hertweck, Elke Dittmann, Muriel Gugger. Unique Biosynthetic Pathway in Bloom-Forming Cyanobacterial Genus Microcystis Jointly Assembles Cytotoxic Aeruginoguanidines and Microguanidines. ACS Chemical Biology. 2018; 14 (1):67-75.
Chicago/Turabian StyleClaire Pancrace; Keishi Ishida; Enora Briand; Douglas Gatte Pichi; Annika R. Weiz; Arthur Guljamow; Thibault Scalvenzi; Nathalie Sassoon; Christian Hertweck; Elke Dittmann; Muriel Gugger. 2018. "Unique Biosynthetic Pathway in Bloom-Forming Cyanobacterial Genus Microcystis Jointly Assembles Cytotoxic Aeruginoguanidines and Microguanidines." ACS Chemical Biology 14, no. 1: 67-75.
Freshwater cyanobacteria are known for their ability to produce bioactive compounds, some of which have been described as allelochemicals. Using a combined approach of co‐cultures and analyses of metabolic profiles, we investigated chemically mediated interactions between two cyanobacterial strains, Microcystis aeruginosa PCC7806 and Planktothrix agardhii PCC7805. More precisely, we evaluated changes in growth, morphology and metabolite production and release by both interacting species. Co‐culture of Microcystis with Planktothrix resulted in a reduction of the growth of Planktothrix together with a decrease of its trichome size and alterations in the morphology of its cells. The production of intracellular compounds by Planktothrix showed a slight decrease between mono and co‐culture conditions. Concerning Microcystis, the number of intracellular compounds was higher under co‐culture condition than under monoculture. Overall, Microcystis produced a lower number of intracellular compounds under monoculture than Planktothrix, and a higher number of intracellular compounds than Planktothrix under co‐culture condition. Our investigation did not allow us to identify specifically the compounds causing the observed physiological and morphological changes of Planktothrix cells. However, altogether, these results suggest that co‐culture induces specific compounds as a response by Microcystis to the presence of Planktothrix. Further studies should be undertaken for identification of such potential allelochemicals. This article is protected by copyright. All rights reserved.
Enora Briand; Sébastien Reubrecht; Florence Mondeguer; Manoëlla Sibat; Philipp Hess; Zouher Amzil; Myriam Bormans. Chemically mediated interactions betweenMicrocystisandPlanktothrix: impact on their growth, morphology and metabolic profiles. Environmental Microbiology 2018, 21, 1552 -1566.
AMA StyleEnora Briand, Sébastien Reubrecht, Florence Mondeguer, Manoëlla Sibat, Philipp Hess, Zouher Amzil, Myriam Bormans. Chemically mediated interactions betweenMicrocystisandPlanktothrix: impact on their growth, morphology and metabolic profiles. Environmental Microbiology. 2018; 21 (5):1552-1566.
Chicago/Turabian StyleEnora Briand; Sébastien Reubrecht; Florence Mondeguer; Manoëlla Sibat; Philipp Hess; Zouher Amzil; Myriam Bormans. 2018. "Chemically mediated interactions betweenMicrocystisandPlanktothrix: impact on their growth, morphology and metabolic profiles." Environmental Microbiology 21, no. 5: 1552-1566.
GNPS is an open-access community-curated analysis platform for sharing natural product mass spectrometry data that enables continuous, automatic reanalysis of deposited 'living' data sets. The potential of the diverse chemistries present in natural products (NP) for biotechnology and medicine remains untapped because NP databases are not searchable with raw data and the NP community has no way to share data other than in published papers. Although mass spectrometry (MS) techniques are well-suited to high-throughput characterization of NP, there is a pressing need for an infrastructure to enable sharing and curation of data. We present Global Natural Products Social Molecular Networking (GNPS; http://gnps.ucsd.edu ), an open-access knowledge base for community-wide organization and sharing of raw, processed or identified tandem mass (MS/MS) spectrometry data. In GNPS, crowdsourced curation of freely available community-wide reference MS libraries will underpin improved annotations. Data-driven social-networking should facilitate identification of spectra and foster collaborations. We also introduce the concept of 'living data' through continuous reanalysis of deposited data.
Mingxun Wang; Jeremy J Carver; Vanessa Phelan; Laura Sanchez; Neha Garg; Yao Peng; Don Duy Nguyen; Jeramie Watrous; Clifford A Kapono; Tal Luzzatto-Knaan; Carla Porto; Amina Bouslimani; Alexey V Melnik; Michael J Meehan; Wei-Ting Liu; Max Crüsemann; Paul D Boudreau; Eduardo Esquenazi; Mario Sandoval-Calderón; Roland D Kersten; Laura Pace; Robert A Quinn; Katherine R Duncan; Cheng-Chih Hsu; Dimitrios J Floros; Ronnie G Gavilan; Karin Kleigrewe; Trent Northen; Rachel J Dutton; Delphine Parrot; Erin E Carlson; Bertrand Aigle; Charlotte F Michelsen; Lars Jelsbak; Christian Sohlenkamp; Pavel Pevzner; Anna Edlund; Jeffrey McLean; Jörn Piel; Brian Murphy; Lena Gerwick; Chih-Chuang Liaw; Yu-Liang Yang; Hans-Ulrich Humpf; Maria Maansson; Rob Keyzers; Amy C Sims; Andrew R Johnson; Ashley M Sidebottom; Brian Sedio; Andreas Klitgaard; Charles B Larson; Cristopher A. Boya P.; Daniel Torres-Mendoza; David J Gonzalez; Denise da Silva; Lucas Maciel Mauriz Marques; Daniel Pecoraro Demarque; Egle Pociute; Ellis C O'Neill; Enora Briand; Eric Jan Nikolaus Helfrich; Eve A Granatosky; Evgenia Glukhov; Florian Ryffel; Hailey Houson; Hosein Mohimani; Jenan J Kharbush; Yi Zeng; Julia A. Vorholt; Kenji L Kurita; Pep Charusanti; Kerry L McPhail; Kristian Fog Nielsen; Lisa Vuong; Maryam Elfeki; Matthew Traxler; Niclas Engene; Nobuhiro Koyama; Oliver B Vining; Ralph Baric; Ricardo da Silva; Samantha J Mascuch; Sophie Tomasi; Stefan Jenkins; Venkat Macherla; Thomas Hoffman; Vinayak Agarwal; Philip Williams; Jingqui Dai; Ram Neupane; Joshua Gurr; Andrés M C Rodríguez; Anne Lamsa; Chen Zhang; Kathleen Dorrestein; Brendan M Duggan; Jehad Almaliti; Pierre-Marie Allard; Prasad Phapale; Louis-Felix Nothias; Theodore Alexandrov; Marc Litaudon; Jean-Luc Wolfender; Jennifer E Kyle; Thomas O Metz; Tyler Peryea; Dac-Trung Nguyen; Danielle VanLeer; Paul Shinn; Ajit Jadhav; Rolf Müller; Katrina Waters; Wenyuan Shi; Xueting Liu; Lixin Zhang; Rob Knight; Paul Jensen; Bernhard Ø Palsson; Kit Pogliano; Roger Linington; Marcelino Gutiérrez; Norberto Lopes; William H Gerwick; Bradley Moore; Pieter C Dorrestein; Nuno Bandeira. Sharing and community curation of mass spectrometry data with Global Natural Products Social Molecular Networking. Nature Biotechnology 2016, 34, 828 -837.
AMA StyleMingxun Wang, Jeremy J Carver, Vanessa Phelan, Laura Sanchez, Neha Garg, Yao Peng, Don Duy Nguyen, Jeramie Watrous, Clifford A Kapono, Tal Luzzatto-Knaan, Carla Porto, Amina Bouslimani, Alexey V Melnik, Michael J Meehan, Wei-Ting Liu, Max Crüsemann, Paul D Boudreau, Eduardo Esquenazi, Mario Sandoval-Calderón, Roland D Kersten, Laura Pace, Robert A Quinn, Katherine R Duncan, Cheng-Chih Hsu, Dimitrios J Floros, Ronnie G Gavilan, Karin Kleigrewe, Trent Northen, Rachel J Dutton, Delphine Parrot, Erin E Carlson, Bertrand Aigle, Charlotte F Michelsen, Lars Jelsbak, Christian Sohlenkamp, Pavel Pevzner, Anna Edlund, Jeffrey McLean, Jörn Piel, Brian Murphy, Lena Gerwick, Chih-Chuang Liaw, Yu-Liang Yang, Hans-Ulrich Humpf, Maria Maansson, Rob Keyzers, Amy C Sims, Andrew R Johnson, Ashley M Sidebottom, Brian Sedio, Andreas Klitgaard, Charles B Larson, Cristopher A. Boya P., Daniel Torres-Mendoza, David J Gonzalez, Denise da Silva, Lucas Maciel Mauriz Marques, Daniel Pecoraro Demarque, Egle Pociute, Ellis C O'Neill, Enora Briand, Eric Jan Nikolaus Helfrich, Eve A Granatosky, Evgenia Glukhov, Florian Ryffel, Hailey Houson, Hosein Mohimani, Jenan J Kharbush, Yi Zeng, Julia A. Vorholt, Kenji L Kurita, Pep Charusanti, Kerry L McPhail, Kristian Fog Nielsen, Lisa Vuong, Maryam Elfeki, Matthew Traxler, Niclas Engene, Nobuhiro Koyama, Oliver B Vining, Ralph Baric, Ricardo da Silva, Samantha J Mascuch, Sophie Tomasi, Stefan Jenkins, Venkat Macherla, Thomas Hoffman, Vinayak Agarwal, Philip Williams, Jingqui Dai, Ram Neupane, Joshua Gurr, Andrés M C Rodríguez, Anne Lamsa, Chen Zhang, Kathleen Dorrestein, Brendan M Duggan, Jehad Almaliti, Pierre-Marie Allard, Prasad Phapale, Louis-Felix Nothias, Theodore Alexandrov, Marc Litaudon, Jean-Luc Wolfender, Jennifer E Kyle, Thomas O Metz, Tyler Peryea, Dac-Trung Nguyen, Danielle VanLeer, Paul Shinn, Ajit Jadhav, Rolf Müller, Katrina Waters, Wenyuan Shi, Xueting Liu, Lixin Zhang, Rob Knight, Paul Jensen, Bernhard Ø Palsson, Kit Pogliano, Roger Linington, Marcelino Gutiérrez, Norberto Lopes, William H Gerwick, Bradley Moore, Pieter C Dorrestein, Nuno Bandeira. Sharing and community curation of mass spectrometry data with Global Natural Products Social Molecular Networking. Nature Biotechnology. 2016; 34 (8):828-837.
Chicago/Turabian StyleMingxun Wang; Jeremy J Carver; Vanessa Phelan; Laura Sanchez; Neha Garg; Yao Peng; Don Duy Nguyen; Jeramie Watrous; Clifford A Kapono; Tal Luzzatto-Knaan; Carla Porto; Amina Bouslimani; Alexey V Melnik; Michael J Meehan; Wei-Ting Liu; Max Crüsemann; Paul D Boudreau; Eduardo Esquenazi; Mario Sandoval-Calderón; Roland D Kersten; Laura Pace; Robert A Quinn; Katherine R Duncan; Cheng-Chih Hsu; Dimitrios J Floros; Ronnie G Gavilan; Karin Kleigrewe; Trent Northen; Rachel J Dutton; Delphine Parrot; Erin E Carlson; Bertrand Aigle; Charlotte F Michelsen; Lars Jelsbak; Christian Sohlenkamp; Pavel Pevzner; Anna Edlund; Jeffrey McLean; Jörn Piel; Brian Murphy; Lena Gerwick; Chih-Chuang Liaw; Yu-Liang Yang; Hans-Ulrich Humpf; Maria Maansson; Rob Keyzers; Amy C Sims; Andrew R Johnson; Ashley M Sidebottom; Brian Sedio; Andreas Klitgaard; Charles B Larson; Cristopher A. Boya P.; Daniel Torres-Mendoza; David J Gonzalez; Denise da Silva; Lucas Maciel Mauriz Marques; Daniel Pecoraro Demarque; Egle Pociute; Ellis C O'Neill; Enora Briand; Eric Jan Nikolaus Helfrich; Eve A Granatosky; Evgenia Glukhov; Florian Ryffel; Hailey Houson; Hosein Mohimani; Jenan J Kharbush; Yi Zeng; Julia A. Vorholt; Kenji L Kurita; Pep Charusanti; Kerry L McPhail; Kristian Fog Nielsen; Lisa Vuong; Maryam Elfeki; Matthew Traxler; Niclas Engene; Nobuhiro Koyama; Oliver B Vining; Ralph Baric; Ricardo da Silva; Samantha J Mascuch; Sophie Tomasi; Stefan Jenkins; Venkat Macherla; Thomas Hoffman; Vinayak Agarwal; Philip Williams; Jingqui Dai; Ram Neupane; Joshua Gurr; Andrés M C Rodríguez; Anne Lamsa; Chen Zhang; Kathleen Dorrestein; Brendan M Duggan; Jehad Almaliti; Pierre-Marie Allard; Prasad Phapale; Louis-Felix Nothias; Theodore Alexandrov; Marc Litaudon; Jean-Luc Wolfender; Jennifer E Kyle; Thomas O Metz; Tyler Peryea; Dac-Trung Nguyen; Danielle VanLeer; Paul Shinn; Ajit Jadhav; Rolf Müller; Katrina Waters; Wenyuan Shi; Xueting Liu; Lixin Zhang; Rob Knight; Paul Jensen; Bernhard Ø Palsson; Kit Pogliano; Roger Linington; Marcelino Gutiérrez; Norberto Lopes; William H Gerwick; Bradley Moore; Pieter C Dorrestein; Nuno Bandeira. 2016. "Sharing and community curation of mass spectrometry data with Global Natural Products Social Molecular Networking." Nature Biotechnology 34, no. 8: 828-837.
The freshwater cyanobacteria, Microcystis sp., commonly form large colonies with bacteria embedded in their mucilage. Positive and negative interactions between Microcystis species and their associated bacteria have been reported. However, the potential role of bacteria in the production and degradation of cyanobacterial secondary metabolites has not been investigated. In this study, a Microcystis-associated bacterial community was isolated and added to the axenic M. aeruginosaPCC7806 liquid culture. After 3years of cocultivation, we studied the bacterial genetic diversity adapted to the PCC7806 strain and compared the intra- and extracellular concentration of major cyanopeptides produced by the cyanobacterial strain under xenic and axenic conditions. Mass spectrometric analyses showed that the intracellular concentration of peptides was not affected by the presence of bacteria. Interestingly, the produced peptides were detected in the axenic media but could not be found in the xenic media. This investigation revealed that a natural bacterial community, dominated by Alpha-proteobacteria, was able to degrade a wide panel of structurally varying cyclic cyanopeptides
Enora Briand; Jean-Francois Humbert; Kevin Tambosco; Myriam Bormans; William H. Gerwick. Role of bacteria in the production and degradation of Microcystis cyanopeptides. MicrobiologyOpen 2016, 5, 469 -478.
AMA StyleEnora Briand, Jean-Francois Humbert, Kevin Tambosco, Myriam Bormans, William H. Gerwick. Role of bacteria in the production and degradation of Microcystis cyanopeptides. MicrobiologyOpen. 2016; 5 (3):469-478.
Chicago/Turabian StyleEnora Briand; Jean-Francois Humbert; Kevin Tambosco; Myriam Bormans; William H. Gerwick. 2016. "Role of bacteria in the production and degradation of Microcystis cyanopeptides." MicrobiologyOpen 5, no. 3: 469-478.
Freshwater cyanobacteria can produce large amount of mucilage, particularly during large blooms. The production of these carbon-rich exopolymers (EPS) should influence the carbon-to-nutrient ratios of the organic matter (OM), which are regularly used as a proxy for the herbivorous food quality. However, little is known about the consequences of EPS production on the carbon-to-nutrient ratio of the OM. Two EPS forms can be distinguished: the free fraction composed of soluble extracellular polymeric substances (S-EPS) and the particulate fraction corresponding to the transparent exopolymer particles (TEP). The aim of the study was to determine whether the TEP and S-EPS productions by cyanobacteria influence the carbon-to-nutrient ratios of the particulate OM (POM). Five cyanobacteria species were grown in batch culture and characterized in terms of photosynthetic activity, EPS production, and C, N, P contents. The variability in EPS production was compared with the variability in stoichiometry of the POM. Most of cyanobacteria live in association with heterotrophic bacteria (HB) within the mucilage. The effect of the presence/absence of HB on EPS production and the carbon-to-nutrient ratios of the POM was also characterized for the cyanobacteria Microcystis aeruginosa. We showed that TEP production increased the carbon-to-nutrient ratios of the POM in the absence of HB, while the stoichiometry did not significantly change when HB were present. The C:N ratio of the POM decreased with production of S-EPS by the five species. Lastly, the three colonial species (Chroococcales) tend to produce more TEP than the two filamentous species (Oscillatoriales), with the two picocyanobacteria being the most productive of both TEP and S-EPS.
Alexandrine Pannard; Julie Pédrono; Myriam Bormans; Enora Briand; Pascal Claquin; Yvan Lagadeuc. Production of exopolymers (EPS) by cyanobacteria: impact on the carbon-to-nutrient ratio of the particulate organic matter. Aquatic Ecology 2015, 50, 29 -44.
AMA StyleAlexandrine Pannard, Julie Pédrono, Myriam Bormans, Enora Briand, Pascal Claquin, Yvan Lagadeuc. Production of exopolymers (EPS) by cyanobacteria: impact on the carbon-to-nutrient ratio of the particulate organic matter. Aquatic Ecology. 2015; 50 (1):29-44.
Chicago/Turabian StyleAlexandrine Pannard; Julie Pédrono; Myriam Bormans; Enora Briand; Pascal Claquin; Yvan Lagadeuc. 2015. "Production of exopolymers (EPS) by cyanobacteria: impact on the carbon-to-nutrient ratio of the particulate organic matter." Aquatic Ecology 50, no. 1: 29-44.
The cyanobacteria Microcystis proliferate in freshwater ecosystems and produce bioactive compounds including the harmful toxins microcystins (MC). These secondary metabolites play an important role in shaping community composition through biotic interactions although their role and mode of regulation are poorly understood. As natural cyanobacterial populations include producing and non‐producing strains, we tested if the production of a range of peptides by coexisting cells could be regulated through intraspecific interactions. With an innovative co‐culturing chamber together with advanced mass spectrometry (MS) techniques, we monitored the growth and compared the metabolic profiles of a MC‐producing as well as two non‐MC‐producing Microcystis strains under mono‐ and co‐culture conditions. In monocultures, these strains grew comparably; however, the non‐MC‐producing mutant produced higher concentrations of cyanopeptolins, aerucyclamides and aeruginosins than the wild type. Physiological responses to co‐culturing were reflected in a quantitative change in the production of the major peptides. Using a MS/MS‐based molecular networking approach, we identified new analogues of known classes of peptides as well as new compounds. This work provides new insights into the factors that regulate the production of MC and other secondary metabolites in cyanobacteria, and suggests interchangeable or complementary functions allowing bloom‐forming cyanobacteria to efficiently colonize and dominate in fluctuating aquatic environments.
Enora Briand; Myriam Bormans; Muriel Gugger; Pieter C. Dorrestein; William H. Gerwick. Changes in secondary metabolic profiles of Microcystis aeruginosa strains in response to intraspecific interactions. Environmental Microbiology 2015, 18, 384 -400.
AMA StyleEnora Briand, Myriam Bormans, Muriel Gugger, Pieter C. Dorrestein, William H. Gerwick. Changes in secondary metabolic profiles of Microcystis aeruginosa strains in response to intraspecific interactions. Environmental Microbiology. 2015; 18 (2):384-400.
Chicago/Turabian StyleEnora Briand; Myriam Bormans; Muriel Gugger; Pieter C. Dorrestein; William H. Gerwick. 2015. "Changes in secondary metabolic profiles of Microcystis aeruginosa strains in response to intraspecific interactions." Environmental Microbiology 18, no. 2: 384-400.
Enora Briand; Myriam Bormans; Catherine Quiblier; Marie-Josã© Salenã§on; Jean-Franã§ois Humbert; Marie-José Salençon. Correction: Evidence of the Cost of the Production of Microcystins by Microcystis aeruginosa under Differing Light and Nitrate Environmental Conditions. PLOS ONE 2012, 7, 1 .
AMA StyleEnora Briand, Myriam Bormans, Catherine Quiblier, Marie-Josã© Salenã§on, Jean-Franã§ois Humbert, Marie-José Salençon. Correction: Evidence of the Cost of the Production of Microcystins by Microcystis aeruginosa under Differing Light and Nitrate Environmental Conditions. PLOS ONE. 2012; 7 (3):1.
Chicago/Turabian StyleEnora Briand; Myriam Bormans; Catherine Quiblier; Marie-Josã© Salenã§on; Jean-Franã§ois Humbert; Marie-José Salençon. 2012. "Correction: Evidence of the Cost of the Production of Microcystins by Microcystis aeruginosa under Differing Light and Nitrate Environmental Conditions." PLOS ONE 7, no. 3: 1.
The cyanobacterium Microcystis aeruginosa is known to proliferate in freshwater ecosystems and to produce microcystins. It is now well established that much of the variability of bloom toxicity is due to differences in the relative proportions of microcystin-producing and non-microcystin-producing cells in cyanobacterial populations. In an attempt to elucidate changes in their relative proportions during cyanobacterial blooms, we compared the fitness of the microcystin-producing M. aeruginosa PCC 7806 strain (WT) to that of its non-microcystin-producing mutant (MT). We investigated the effects of two light intensities and of limiting and non-limiting nitrate concentrations on the growth of these strains in monoculture and co-culture experiments. We also monitored various physiological parameters, and microcystin production by the WT strain. In monoculture experiments, no significant difference was found between the growth rates or physiological characteristics of the two strains during the exponential growth phase. In contrast, the MT strain was found to dominate the WT strain in co-culture experiments under favorable growth conditions. Moreover, we also found an increase in the growth rate of the MT strain and in the cellular MC content of the WT strain. Our findings suggest that differences in the fitness of these two strains under optimum growth conditions were attributable to the cost to microcystin-producing cells of producing microcystins, and to the putative existence of cooperation processes involving direct interactions between these strains.
Enora Briand; Myriam Bormans; Catherine Quiblier; Marie-José Salençon; Jean-François Humbert. Evidence of the Cost of the Production of Microcystins by Microcystis aeruginosa under Differing Light and Nitrate Environmental Conditions. PLoS ONE 2012, 7, e29981 .
AMA StyleEnora Briand, Myriam Bormans, Catherine Quiblier, Marie-José Salençon, Jean-François Humbert. Evidence of the Cost of the Production of Microcystins by Microcystis aeruginosa under Differing Light and Nitrate Environmental Conditions. PLoS ONE. 2012; 7 (1):e29981.
Chicago/Turabian StyleEnora Briand; Myriam Bormans; Catherine Quiblier; Marie-José Salençon; Jean-François Humbert. 2012. "Evidence of the Cost of the Production of Microcystins by Microcystis aeruginosa under Differing Light and Nitrate Environmental Conditions." PLoS ONE 7, no. 1: e29981.
We assessed the temporal variability of nutrients, phytoplankton and bacterioplankton at two sites of different trophic status in New Caledonia’s South-West lagoon, a tropical coastal ecosystem. During stable meteorological conditions, Chl.a, bacterial production and nutrient concentrations experience weak but consistent daily variation. Short-term (1–2 week interval) fluctuations of planktonic variables are in the same range as annual variations at both sites. A part of these short term variations is linked to local meteorological events (wind in the main channel, precipitation at the coastal station). Although annual variations are weak compared to short term variations, phytoplankton and bacterioplankton production show consistent temporal patterns, with maxima in December–January and April–May and minima in August. Annual bacterial production represents 21% and 34% of particulate primary production at the oligotrophic and mesotrophic sites, respectively. Mineral nutrient availability indicates that nitrogen is probably the primary limiting factor of phytoplankton throughout the year.
Jean-Pascal Torréton; Emma Rochelle-Newall; Olivier Pringault; Séverine Jacquet; Vincent Faure; Enora Briand. Variability of primary and bacterial production in a coral reef lagoon (New Caledonia). Marine Pollution Bulletin 2010, 61, 335 -348.
AMA StyleJean-Pascal Torréton, Emma Rochelle-Newall, Olivier Pringault, Séverine Jacquet, Vincent Faure, Enora Briand. Variability of primary and bacterial production in a coral reef lagoon (New Caledonia). Marine Pollution Bulletin. 2010; 61 (7-12):335-348.
Chicago/Turabian StyleJean-Pascal Torréton; Emma Rochelle-Newall; Olivier Pringault; Séverine Jacquet; Vincent Faure; Enora Briand. 2010. "Variability of primary and bacterial production in a coral reef lagoon (New Caledonia)." Marine Pollution Bulletin 61, no. 7-12: 335-348.
With the aim of explaining the variations in microcystin (MC) concentrations during cyanobacterial blooms, we studied several Microcystis aeruginosa populations blooming in different freshwater ecosystems located in the same geographical area. As assessed by real-time PCR, it appeared that the potentially MC-producing cells ( mcyB + ) were predominant (70 to 100%) in all of these M. aeruginosa populations, with the exception of one population in which non-MC-producing cells always dominated. Apart from the population in the Grangent Reservoir, we found that the proportions of potentially MC-producing and non-MC-producing cells varied little over time, which was consistent with the fact that according to a previous study of the same populations, the intergenic transcribed spacer (ITS) genotype composition did not change (38). In the Grangent Reservoir, the MC-RR variant was the dominant microcystin variant throughout the bloom season, despite changes in the ITS composition and in the proportions of mcyB + cells. Finally, the variations in total MC concentrations (0.3 to 15 μg liter −1 ) and in the MC cellular quotas (0.01 to 3.4 pg cell −1 ) were high both between and within sites, and no correlation was found between the MC concentrations and the proportion of mcyB + cells. All of these findings demonstrate that very different results can be found for the proportions of potentially MC-producing and non-MC-producing cells and MC concentrations, even in M. aeruginosa populations living in more or less connected ecosystems, demonstrating the importance of the effect of very local environmental conditions on these parameters and also the difficulty of predicting the potential toxicity of Microcystis blooms.
M. Sabart; D. Pobel; E. Briand; B. Combourieu; M. J. Salençon; J. F. Humbert; D. Latour. Spatiotemporal Variations in Microcystin Concentrations and in the Proportions of Microcystin-Producing Cells in Several Microcystis aeruginosa Populations. Applied and Environmental Microbiology 2010, 76, 4750 -4759.
AMA StyleM. Sabart, D. Pobel, E. Briand, B. Combourieu, M. J. Salençon, J. F. Humbert, D. Latour. Spatiotemporal Variations in Microcystin Concentrations and in the Proportions of Microcystin-Producing Cells in Several Microcystis aeruginosa Populations. Applied and Environmental Microbiology. 2010; 76 (14):4750-4759.
Chicago/Turabian StyleM. Sabart; D. Pobel; E. Briand; B. Combourieu; M. J. Salençon; J. F. Humbert; D. Latour. 2010. "Spatiotemporal Variations in Microcystin Concentrations and in the Proportions of Microcystin-Producing Cells in Several Microcystis aeruginosa Populations." Applied and Environmental Microbiology 76, no. 14: 4750-4759.
The ISME Journal: Multidisciplinary Journal of Microbial Ecology is the official Journal of the International Society for Microbial Ecology, publishing high-quality, original research papers, short communications, commentary articles and reviews in the rapidly expanding and diverse discipline of microbial ecology.
Enora Briand; Nicolas Escoffier; C; [Eacute]; Cile Straub; Marion Sabart. Spatiotemporal changes in the genetic diversity of a bloom-forming Microcystis aeruginosa (cyanobacteria) population. The ISME Journal 2008, 3, 419 -429.
AMA StyleEnora Briand, Nicolas Escoffier, C, [Eacute], Cile Straub, Marion Sabart. Spatiotemporal changes in the genetic diversity of a bloom-forming Microcystis aeruginosa (cyanobacteria) population. The ISME Journal. 2008; 3 (4):419-429.
Chicago/Turabian StyleEnora Briand; Nicolas Escoffier; C; [Eacute]; Cile Straub; Marion Sabart. 2008. "Spatiotemporal changes in the genetic diversity of a bloom-forming Microcystis aeruginosa (cyanobacteria) population." The ISME Journal 3, no. 4: 419-429.
The factors that control the production of microcystins (hepatotoxins) during cyanobacterial blooms, and the function of these metabolites remain largely unknown. In an attempt to provide answers to these questions, we compared the fitness of microcystin (MC)‐producing and non‐MC‐producing Planktothrix agardhii strains under various experimental conditions. More specifically, we investigated the effects of temperature, light intensity and nitrate concentrations on several MC‐producing and non‐MC‐producing strains in monoculture and competition experiments. In the monoculture experiments, no significant difference in cell growth rates was found for any of the environmental conditions tested. On the other hand, at the end of the competition experiments, we found that when the environmental conditions limited cell growth, MC‐producing strains were clearly winning out over the non‐MC‐producing ones. This suggested that, under growth‐limiting conditions, the benefits of producing MC outweigh the cost. Moreover, the reverse was found under non‐growth‐limiting conditions, suggesting that under environmental conditions that favour cyanobacterial growth, the cost of MC production must outweigh its benefits. These findings suggest that environmental factors may have an indirect effect on the MC production rate, and on the selection of MC‐producing and non‐MC‐producing strains, via their direct impact on both the cell growth rate and the cell densities in the cultures. Several hypotheses have been advanced concerning the possible function of MCs, but none of them seems to be supported by our data.
Enora Briand; Claude Yéprémian; Jean-François Humbert; Catherine Quiblier. Competition between microcystin- and non-microcystin-producingPlanktothrix agardhii(cyanobacteria) strains under different environmental conditions. Environmental Microbiology 2008, 10, 3337 -3348.
AMA StyleEnora Briand, Claude Yéprémian, Jean-François Humbert, Catherine Quiblier. Competition between microcystin- and non-microcystin-producingPlanktothrix agardhii(cyanobacteria) strains under different environmental conditions. Environmental Microbiology. 2008; 10 (12):3337-3348.
Chicago/Turabian StyleEnora Briand; Claude Yéprémian; Jean-François Humbert; Catherine Quiblier. 2008. "Competition between microcystin- and non-microcystin-producingPlanktothrix agardhii(cyanobacteria) strains under different environmental conditions." Environmental Microbiology 10, no. 12: 3337-3348.
The study of lysogeny in aquatic systems is an often overlooked aspect of microbial ecology, especially in tropical environments. Herein, the fraction of lysogenized cells (FLC) was detected in the surface waters of 20 coastal stations distributed from the eutrophicated shoreline to seaward waters of Hann Bay (Senegal). Concurrently, viral lytic infection rates were extrapolated from the frequency of visibly infected bacterial cells (FVIC), as determined from transmission electron microscopy observations. The experimental induction of prophage was observed in less than 3% of indigenous marine bacteria, suggesting that lysogenic stages of infection are rare in Hann Bay. Similarly, only 0.5–4.7% of bacteria showed visible signs of lytic infection. However, the positive correlation between the fraction of lysogenic and lytic cells (r = 0.67, p < 0.05, n = 20) may actually indicate that the coexistence of both lifestyles may be due to the massive and rapid induction of lysogens, potentially from the high levels of local UV radiation. Overall, we suggest that the determination of FVIC and FLC to examine the predominance of one type of cycle versus the other may be a source of misinterpretation in some particular aquatic environments.
Yvan Bettarel; Robert Arfi; Thierry Bouvier; Marc Bouvy; Enora Briand; Jonathan Colombet; Daniel Corbin; Télesphore Sime-Ngando. Virioplankton distribution and activity in a tropical eutrophicated bay. Estuarine, Coastal and Shelf Science 2008, 80, 425 -429.
AMA StyleYvan Bettarel, Robert Arfi, Thierry Bouvier, Marc Bouvy, Enora Briand, Jonathan Colombet, Daniel Corbin, Télesphore Sime-Ngando. Virioplankton distribution and activity in a tropical eutrophicated bay. Estuarine, Coastal and Shelf Science. 2008; 80 (3):425-429.
Chicago/Turabian StyleYvan Bettarel; Robert Arfi; Thierry Bouvier; Marc Bouvy; Enora Briand; Jonathan Colombet; Daniel Corbin; Télesphore Sime-Ngando. 2008. "Virioplankton distribution and activity in a tropical eutrophicated bay." Estuarine, Coastal and Shelf Science 80, no. 3: 425-429.