My research focuses on microbes involved in nutrient cycling in the ocean, especially of the element nitrogen. I am interested in cultivating new microbes and discovering novel ways of tracking their activity. This research combines laboratory experiments with field observations, and to date has used genomics, transcriptomics, proteomics and stable isotope geochemistry as tools to uncover the activity of microbes in the mesopelagic ocean. A particular focus of the lab is the marine archaea, a largely uncultured group of microbes. Findings from our recent research include the discovery that archaea in the ocean can make the greenhouse gas nitrous oxide, and that some marine archaea have exceptionally small genomes.