About his PhD project

Diazotrophs are prokaryotes capable of reducing atmospheric dinitrogen (N2) to reactive nitrogen, the main nutrient sustaining life in the ocean. The majority of diazotrophs live attached to "marine snow": amorphous aggregations of cell debris, polysaccharides and detritus that form by interaction of dead cells suspended in seawater [1]. Marine snow is rich in nutrients and energy, and hence thought to provide resources for diazotrophs to thrive in the ocean. However, how diazotrophs swim towards and colonize marine snow, and how such colonization stimulates their metabolism has not been studied. This project will combine cell trajectory tracking and analysis on model marine snow [2] with single-cell mass spectrometry [3] to understand how diazotroph colonization dynamics and metabolism differ among i) marine snow types, ii) environmental conditions, and iii) diazotroph species.