PR002533 (Project)

Description:Various studies suggest that global change is causing an increase in phytoplankton biomass, cyanobacteria prevalence and cyanotoxin production. Metabolomics approaches in natural system hold great promise in investigating the factors leading to variations in phytoplankton successions and subsequent cyanotoxin production. However, eco-metabolomics studies are still scarce in literature and suffer to adequately unravel the biologically relevant variables under environmental changes. In this study, we investigate the temporal and spatial dynamics of phytoplankton community and the production of their primary and secondary untargeted metabolites in response to seasonal variations. Thus, we collected water samples in two points of the Aydat Lake (France): near the inflowing waters from Veyre River and at the middle of the lake during the 2021 summer. Untargeted intracellular metabolites were measured using ultra-high-performance liquid chromatography coupled with a high-resolution mass spectrometer, as well as phytoplankton biovolume and diversity and physicochemical lake’s parameters. Our results highlight the existence of local metabolomic niches, as we report significant difference in the intra-cellular content in metabolites between the 2 sampling sites, separated by only 200m, while phytoplankton communities were similar.