@article {5864, title = {{OZCAR}: The French Network of Critical Zone Observatories}, journal = {Vadose Zone Journal}, volume = {17}, year = {2018}, doi = {10.2136/vzj2018.04.0067}, url = {https://doi.org/10.2136/vzj2018.04.0067}, author = {J. Gaillardet and I. Braud and F. Hankard and S. Anquetin and O. Bour and N. Dorfliger and J.R. de Dreuzy and S. Galle and C. Galy and S. Gogo and L. Gourcy and F. Habets and F. Laggoun and L. Longuevergne and T. Le Borgne and F. Naaim-Bouvet and G. Nord and V. Simonneaux and D. Six and T. Tallec and C. Valentin and Gwena{\"e}l Abril and P. Allemand and A. Ar{\`e}nes and B. Arfib and L. Arnaud and N. Arnaud and P. Arnaud and S. Audry and V. Bailly Comte and C. Batiot and A. Battais and H. Bellot and E. Bernard and C. Bertrand and H. Bessi{\`e}re and S. Binet and J. Bodin and X. Bodin and L. Boithias and J. Bouchez and B. Boudevillain and I. Bouzou Moussa and F. Branger and J. J. Braun and P. Brunet and B. Caceres and D. Calmels and B. Cappelaere and H. Celle-Jeanton and F. Chabaux and K. Chalikakis and C. Champollion and Y. Copard and C. Cotel and P. Davy and P. Deline and G. Delrieu and J. Demarty and C. Dessert and M. Dumont and C. Emblanch and J. Ezzahar and M. Est{\`e}ves and V. Favier and M. Faucheux and N. Filizola and P. Flammarion and P. Floury and O. Fovet and M. Fournier and A. J. Francez and L. Gandois and C. Gascuel and E. Gayer and C. Genthon and M. F. G{\'e}rard and D. Gilbert and I. Gouttevin and M. Grippa and G. Gruau and A. Jardani and L. Jeanneau and J. L. Join and H. Jourde and F. Karbou and D. Labat and Yvan Lagadeuc and E. Lajeunesse and R. Lastennet and W. Lavado and E. Lawin and T. Lebel and C. Le Bouteiller and C. Legout and Y. Lejeune and E. Le Meur and N. Le Moigne and J. Lions and A. Lucas and J. P. Malet and C. Marais-Sicre and J. C. Mar{\'e}chal and C. Marlin and P. Martin and J. Martins and J. M. Martinez and N. Massei and A. Mauclerc and N. Mazzilli and J. Mol{\'e}nat and P. Moreira-Turcq and E. Mougin and S. Morin and J. Ndam Ngoupayou and G. Panthou and C. Peugeot and G. Picard and M. C. Pierret and G. Porel and A. Probst and J. L. Probst and A. Rabatel and D. Raclot and L. Ravanel and F. Rejiba and P. Ren{\'e} and O. Ribolzi and J. Riotte and A. Rivi{\`e}re and H. Robain and L. Ruiz and J. M. Sanchez-Perez and W. Santini and S. Sauvage and P. Schoeneich and J. L. Seidel and M. Sekhar and O. Sengtaheuanghoung and N. Silvera and M. Steinmann and A. Soruco and G. Tallec and E. Thibert and D. Valdes Lao and C. Vincent and D. Viville and P. Wagnon and R. Zitouna} } @article {4159, title = {Production of exopolymers (EPS) by cyanobacteria: impact on the carbon-to-nutrient ratio of the particulate organic matter}, journal = {Aquatic Ecology}, year = {2015}, pages = {1-16}, abstract = {
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.