Marine dissolved organic matter (DOM) is a key component of the global carbon cycle. While marine DOM properties are usually characterized by chemical approaches, an effort to integrate its variations in an ecological perspective is needed. Heterotrophic prokaryotes being the main consumers of marine DOM, targeting their responses to varying DOM properties provides an effect-based characterization of DOM properties. Dilution e...

In the marine coastal environment, freshwater and seawater coalescing communities are facing a complex set of abiotic and biotic cross-influences. This study aimed at evaluating the respective influences of blending and prokaryotic dynamics on community structure. For that, the surface salinity gradient of a nutrient-rich estuary (Arno River, Mediterranean Sea, Italy) was sampled at regular salinity intervals. When considering...

The predicted increase in allochthonous dissolved organic carbon (DOC) in high‐altitude lakes is expected to alter the phytoplankton–bacterioplankton relationship. However, few studies address the influence of summer phytoplankton dynamics on microbial responses to DOC additions. We sampled natural plankton assemblages during two contrasting periods of summer in a high‐altitude lake in the French Alps and subjected them to glu...

Microbial colonization of artificial substrates in coastal areas, which concerns hull ships, sensors as well as plastic debris, is of huge significance to attain a rational environmental management. Some surface and environmental drivers of biofilm development have previously been described but their relative impact on the formation of biofilms remains unknown while crucial. Especially, there is no evidence of the relative imp...

Summary In the context of global warming, this study aimed to assess the effect of temperature and irradiance on the macroalgal Taonia atomaria holobiont dynamics. We developed an experimental set‐up using aquaria supplied by natural seawater with three temperatures combined with three irradiances. The holobiont response was monitored over 14 days using a multi‐omics approach coupling algal surface metabolomics and metabarcodi...

Estuarine processes play a key role in determining the amount and quality of land-derived dissolved organic matter (DOM) reaching the oceans. Microbial-mediated reactions can affect the concentration, quality, and bioavailability of DOM within an estuary. In this study, we investigated biological DOM removal in a small estuary and its variability in two contrasting seasons (spring and autumn) characterized by natural differenc...

Summary M icrocystis is a toxic freshwater cyanobacterium with an annual life cycle characterized by the alternation of a planktonic proliferation stage in summer and a benthic resting stage in winter. Given the importance of both stages for the development and the survival of the population, we investigated the genotypic composition of the planktonic and benthic M icrocystis subpopulations from the Grangent reservoir ( F ranc...