Nitrate Reductase

Metalloenzyme distributions in oxygen minimum zones

Collaborators: Mak Saito and Mike Jakuba, WHOI; John Brier, UTRGV

This project is an interdisciplinary chemistry, biology, and engineering effort to quantify the abundance of trace metal containing enzymes—metalloenzymes—in the mesopelagic ocean and test the hypothesis that reactions in the nitrogen cycle, in particular nitrite (NO2-) oxidation, could become limited by metal availability, and that trace metal demands for these organisms may be increased under low oxygen conditions.

One of the challenges to characterizing the biogeochemistry of the mesopelagic ocean is an inability to effectively sample it. As a sampling platform we will use the novel biogeochemical AUV Clio that enables high-resolution vertical profile samples for biochemical and microbial measurements by large volume filtration of microbial particulate material on a research expedition in the Eastern Tropical Pacific Ocean. 

(Image: E. coli NarGHI crystal structure, from RCSB PDB)