Speaker: Dr. Maria Pachiadaki, WHOI

Title: Dark ocean chemoautorophy and other tales from tiny organisms with big impact.

Abstract: Microbial inhabitants of the dark ocean (i.e. ocean water below the sunlight surface layer) comprise one of the largest biomes on Earth. They mediate all major biogeochemical cycles, control the “dark end” of ocean’s biological carbon pump, and can have pronounced effects on climate. Yet, little is known about the key chemoautotrophic and heterotrophic taxa in the aphotic realm, their global distribution, and their relative activities. My lab, together with a large network of collaborators, aims to address major gaps in our knowledge of the dark ocean microbiome by applying in situ approaches to accurately measure rates of key microbiological processes, reveal the genomic blueprint of active single cells involved in these processes, and quantify the expression of the associated metabolic pathways.