The effects of the abrupt input of high quantities of dissolved inorganic nitrogen and phosphorus on prokaryotic and eukaryotic microbial plankton were investigated in an attempt to simulate the nutrient disturbances caused by eutrophication and climate change. Two nutrient levels were created through the addition of different quantities of dissolved nutrients in a mesocosm experiment. During the developed blooms, compositional differences were found within bacteria and microbial eukaryotes, and communities progressed towards species of faster metabolisms. Regarding the different nutrient concentrations, different microbial species were associated with each nutrient treatment and community changes spanned from the phylum to the operational taxonomic unit (OTU) level. Network analyses revealed important differences in the biotic connections developed: more competitive relationships were established in the more intense nutrient disturbance and networks of contrasting complexity were formed around species of different ecological strategies. This work highlights that sudden disturbances in water column chemistry lead to the development of entirely different microbial food webs with distinct ecological characteristics.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work was funded by the European Union and Greek national funds through the Operational Program “Education and Lifelong Learning” of the National Strategic Reference Framework (NSRF) – ARISTEIA II (HYPOXIA project, No 4705), and by King Abdullah University of Science and Technology (KAUST) through baseline funding to DD. We are grateful to the participants of the mesocosm experiment for their significant help during experimental setup and sampling: S. Diliberto, C. Frangoulis, A. Geropoulos, V. Kalogeropoulou, M. Kanellopoulou, M. Moraitis, and Tsikopoulou I. Special thanks are attributed to E. Dafnomili, M. Kagiorgi and S. Zivanovic for assistance with dissolved nutrients analyses and G. Piperakis for inspiring technical assistance. J.B. Kristoffersen and C. Pavloudi are greatly acknowledged for valuable advising during molecular analyses.This work was funded by the European Union and Greek national funds through the Operational Program “Education and Lifelong Learning” of the National Strategic Reference Framework (NSRF) – ARISTEIA II (HYPOXIA project, No 5381), and by King Abdullah University of Science and Technology (KAUST) through baseline funding to DD. The authors declare no conflict of interest. All authors have approved the final submitted manuscript.