MaRine VOC interactions

Description du projet

Émissions de COV dans l’environnement marin

Les composés organiques volatils (COV) sont des molécules de faible poids moléculaire ayant une pression de vapeur élevée, importantes pour la chimie atmosphérique en tant que précurseurs de l’ozone. Alors que les émissions terrestres de COV sont bien estimées, les émissions marines demeurent mal connues en raison du manque de données et de leur variabilité. Soutenu par le programme Actions Marie Skłodowska-Curie, le projet MaRVOC va étudier les émissions de COV dans les environnements marins, en concentrant ses recherches sur les interactions biotiques. Il identifiera les organismes qui produisent des COV et les facteurs qui influencent leurs émissions. Le projet combinera l’analyse des COV par spectrométrie de masse avec des techniques moléculaires avancées pour explorer les interactions, les taxons et les gènes impliqués dans la production de COV marins, par le biais d’expériences en mésocosme et sur le terrain. Cette recherche entend combler d’importantes lacunes dans les connaissances et améliorer notre compréhension des cycles biogéochimiques marins.

Objectif

Volatile organic compounds (VOCs) are diverse bioactive molecules of low molecular weight and high vapor pressure. VOCs are produced by biotic and abiotic processes and are important for atmospheric chemistry as main biogenic precursors of ozone, which is a toxic and potent greenhouse gas. In terrestrial ecosystems, a total emission of 760 Tg (C) yr−1 is estimated from terrestrial vegetation and more than 30.000 VOCs that are released from plants through secondary metabolism pathways have been identified. These VOCs also have great impact acting as inhibitors/stimulators of growth, as protectors against herbivores and pathogens, and as signal molecules in internal and external communication. Despite that the oceans cover 70 % of the Earth’s surface, the emission processes of VOCs from the marine environment are still unknown. The VOC emission from the ocean is very difficult to estimate because data are sparse and rates are highly variable, depending strongly on the abundance and species of phytoplankton, biotic interactions and sinks of these compounds. The aim of this proposed project is to study the biology behind VOC emissions in marine environments and in particular address the importance of biotic interactions: This includes the specific organisms producing these compounds, under what circumstances, and how specific interactions influence VOC emissions. This proposal will for the first time combine novel mass spectrometry-based methods for VOC analysis with cutting edge molecular methods to identify interactions, taxa and functionalities (genes) involved in marine VOC production from mesocosm, phytoplankton-bacteria interactions experiments and fieldwork. I will carry out this research with the supervisors, Prof. Lasse Riemann and Prof. Riikka Rinnan at the Center for Volatile Interactions (VOLT) Centre of Excellence at Copenhagen University. Over the proposal, I will acquire new expertise in molecular biology and VOC analysis by ion mass spectrometry.