Marine DOM molecular characterization using an Orbitrap Q Exactive mass spectrometer

The objective of this work is to study the influence of different chemical properties of DOM and inorganic nutrients on the heterotrophic basis of the planktonic food web in order to provide evidence for the hierarchy of the main factors controlling the fate of DOM in environments. coastal sailors. DOM from two contrasting environments, with similar dissolved organic carbon (DOC) concentrations, but different DOM chemical composition and nutrient availability, were incubated with two microbial communities exhibiting short-term life histories and contrasting taxonomic structures. In order to compare the influences of the chemical properties of DOM, we measured various parameters for 22 days, including (i) the concentrations and availability of inorganic and organic nutrients and carbon, (ii) changes in the elemental and molecular composition of DOM, (iii) fluorescence. properties of DOM, (iv) growth of heterotrophic prokaryotes and (v) taxonomic diversity of prokaryotes.