Project description:Non-targeted LC-MS/MS analysis of PPL solid phase extracted dissolved organic matter (DOM) from TARA/TREC Expedition Leg 1, collected in the coastal Atlantic between France to Netherlands in Spring 2023.
Project description:LC-MS/MS based (pos mode) non-targeted Metabolomics from PPL solid-extracted DOM from EXPORTS.
Rerun of Samples after 2 month storage at -80 C.
Project description:Diazotrophs provide the main source of reactive nitrogen to the ocean, sustaining primary productivity and CO2 uptake. Climate change is raising temperatures, decreasing pH and reducing nutrient availability. How microbes respond to these changes is largely unexplained. Similarly, the role of DOM in the growth and survival of certain diazotrophic organisms is poorly understood. Moreover, growing evidence indicates some diazotrophs are capable of utilizing distinct DOM compounds via osmotrophy providing them with additional metabolic plasticity and ecological advantages compared to other non-diazotrophic microbes. We aimed to understand how osmotrophy could modify carbon uptake and alleviate energy stress in diazotrophs under ongoing climate change perturbations. We hypothesized that Crocosphaera preferentially uses DOM when labile as a carbon source in present pH conditions, as compared to future more acidic scenarios with higher access to inorganic carbon. Alternatively, the lower pH may cause Crocosphaera to be energy limited when trying to maintain intracellular homeostasis which would favour DOM uptake as an extra source of energy.
Project description:Non-targeted LC-MS/MS analysis of DOM and POM samples form the Pacific Ocean (Californian off-shore) taken via PPL solid-phase extraction and GFF filtering.
Project description:Acidified C18 and acidified and untreated PPL SPE extracted DOM samples taken during a 9-day study off the Scripps Pier in La Jolla (Non-targeted LC-MS/MS, positive mode).