Descrizione del progetto
Comprendere l’equilibrio metabolico dell’oceano
Circa il 98 % della biomassa dell’oceano è costituito da microrganismi quali il minuscolo fitoplancton delle alghe. Il ruolo del fitoplancton nella fotosintesi terrestre è fondamentale, in quanto cattura l’anidride carbonica (CO2) consentendo all’oceano di rilasciare importanti risorse viventi e ossigeno (O2). Inoltre, esso stimola la respirazione microbica, un processo metabolico essenziale per controbilanciare la fotosintesi e restituire carbonio organico sotto forma di CO2. Tuttavia, le conoscenze relative alla respirazione microbica sono ancora limitate. Il progetto BULLE finanziato dall’UE esaminerà l’equilibrio tra fotosintesi e respirazione nel metabolismo dell’oceano, studiando l’evoluzione dalla produzione di CO2 a quella di O2, detta «quoziente respiratorio (QR)». Il progetto applicherà tecnologie e metodi innovativi per capire come le caratteristiche chimiche delle sostanze nutritive regolino il QR nelle cellule dei batteri, e per approfondire le interconnessioni tra QR, produzione primaria netta e attività batteriche.
Obiettivo
About 98% of the ocean’s biomass is composed of microorganisms like the tiny algae, phytoplankton. Tiny but mighty when it comes at capturing carbon dioxide (CO2). Phytoplankton acts for half of the Earth’s photosynthesis, allowing ocean’s to supply major living resources and dioxygen (O2). Microbial respiration is the other fundamental biological process that counterbalances photosynthesis and returns organic carbon back as CO2. Yet, despite ocean’s pivotal role in global climate, microbial respiration remains one of the least explored metabolic processes; so that, whether oligotrophic ocean is a net sink or source of CO2, is highly debated for the last 20 years. The BULLE project aims to evaluate the ocean’s metabolic balance between photosynthesis and respiration by looking at the production of CO2 evolved to that O2 consumed by marine bacteria, the so-called “respiratory quotient” (RQ). Limits of detection of biological CO2 production have left RQ measurements far behind the multitude of investigations of photosynthesis. BULLE will face these challenges using the most recent technologies. The project strongly relies on the multidisciplinary expertise I will share with my host lab to tackle this issue at both cellular and community level. Specifically, BULLE aims to (1) investigate how the chemical characteristics of nutrients (Fe and C) regulate the RQ in bacterial cells and (2) study the links between the RQ, net primary production and bacterial activities. An innovative aspect of BULLE is the implementation of continuous measurements of O2/N2 and pCO2 concentrations respiration, and the deployment of In Situ Oxygen Dynamic Autosampler (IODA) instrumentation in the coastal NW Mediterranean Sea. The training I will receive with BULLE will help me give my career a new direction from a lab expertise towards high resolution in situ observations. In return, I will transfer my experience in microbial metabolisms and radioisotopes tracking methods to the host team.
Campo scientifico
Programma(i)
Argomento(i)
Meccanismo di finanziamento
MSCA-IF - Marie Skłodowska-Curie Individual Fellowships (IF)Coordinatore
13284 Marseille
Francia