Project: Collaborative Research: Multiple Analytical Window Electrochemical Techniques and Meta-Omics Applied to Studies of Iron Recycling and Iron-Binding Ligands in the Ocean

NSF Award Abstract:
The importance of iron (Fe) as a limiting micronutrient in the ocean is a relatively new discovery. And while critical advances have been made in understanding the marine iron cycle, a full description remains elusive due to its biogeochemical complexity and the low concentrations of iron in the ocean. The research funded in this project seeks to advance our understanding of the chemical forms of Fe in seawater. This will be done by first refining a novel, selective electrochemical analytical method for looking at Fe at natural concentrations in seawater and then relating the resulting data to the genetic composition of the microbial communities responsible for creating the organic molecules that control the fate and chemical form of Fe in the ocean. We now know that iron is an incredibly important micronutrient to biological communities, and this new approach of linked genomic and analytical data has the potential to provide important insights that will significantly advance the study of iron composition in the ocean. This project will also support two graduate students at Scripps Institute of Oceanography, both participating in a new outreach program with 6th graders initiated by the Birch Aquarium at Scripps.

The importance of iron as a limiting micronutrient in the ocean has become a topic of avid research, and there have been many advances in the field. However, characterizations of iron speciation in seawater are still broad by nature due to the lack of precision in the electrochemical analytical techniques. Competitive ligand exchange - adsorptive cathodic stripping voltammetry (CLE-ACSV) has been a commonly used technique to study iron speciation in seawater. This research seeks to improve this method by applying CLE-ACSV at multiple analytical windows (MAW) to increase resolution at the strong and weak ends of the iron-binding ligand spectrum. Additionally, by relating data from this technique to data on the metagenomic composition of the resident microbial community, the work should be able to make meaningful connections between the microbial communities that produce the organic ligands that we now know dominate iron speciation, solubility, and uptake in the ocean. This research has the potential to make a significant contribution to the current understanding of iron cycling in seawater, and it will help us to better understand the larger global ocean biogeochemical processes that control the distribution and availability of iron and its controls on global productivity.