My research focuses in microbial nitrogen (N) fixation in open ocean waters. This process provides most of the bioavailable N to the oceans and is carried out by a reduced functional group of prokaryotes, named diazotrophs. Despite their crucial contribution to the ocean’s N cycle, recent evidence suggests that the activities and diversity of marine diazotrophic communities have been underestimated. In particular, non-cyanobacterial diazotrophs have been shown to be widely distributed among the world’s oceans, and have the potential to be key players in nitrogen fixation.
My interests lie in combining field and laboratory work to determine whether non-cyanobacterial diazotrophs play a significant role in the contribution to the oceanic nitrogen input. This requires the combination of methods from geochemistry and molecular biology, such as the following:
• Nitrogen and Carbon fixation measurements with stable isotope techniques
• Single-cell contributions to the community’s N input
• Use and development of molecular tools for identification of uncultured diazotrophs
• Molecular characterization of diazotroph isolates