ODU RESEARCHERS RECEIVE COLLABORATIVE NSF GRANT TO EXPLORE SEAWATER PROCESS

Two Old Dominion University faculty members, geochemist Patrick Hatcher and oceanographer Margaret Mulholland, have been awarded a collaborative research grant of $276,000 from the National Science Foundation to explore the role that decay-resistant proteinaceous material plays in the sequestration of carbon and nitrogen in seawater.

Their project, which began in September and will continue through August 2009, is titled "Resistance of Peptide Degradation Products in Seawater." The researchers will investigate reaction mechanisms affecting fractional pieces of proteins called peptides, evaluating the capability of these bits of organic matter to remove carbon and nitrogen from marine cycles.

Photosynthetic microorganisms take in carbon and nitrogen as they grow, and their remains make up most of the dissolved organic matter (DOM) in the oceans. Most of the carbon and nitrogen is recycled as the organic matter degrades, becoming available to help to grow another generation of microorganisms. But some organic matter resists decay and becomes stable-also called "refractory"-DOM that binds up carbon and nitrogen to make them biologically unavailable.

"Little is known about the chemical composition of refractory DOM, or about mechanisms contributing to its resistance" to degradation, Hatcher and Mulholland wrote in a project summary. Research in this area is needed, they contend, because the recycling of essential chemicals is so important to the growth of microorganisms and to the overall food chain and biological productivity of the oceans.

Hatcher, who is Batten Endowed Chair in Physical Sciences, is the director of ODU's College of Sciences Major Instrumentation Cluster (COSMIC). He will use nuclear magnetic resonance (NMR) spectroscopy in the COSMIC facility to track biological and abiological processes for carbon and nitrogen sequestration into DOM.

"Last year I published a paper suggesting that biologically produced molecules can become associated with dissolved organic matter via an abiotic process and we are testing the hypothesis that this might be important to nitrogen sequestration," he said.

Mulholland, an associate professor of oceanography, is an expert in carbon and nitrogen cycling in aquatic systems and a member of the Scientific and Technical Advisory Committee of the Chesapeake Bay Program. Her interests include the aquatic availability of nitrogen, such as that coming from wastewater discharges and runoff that can fuel dangerous algal blooms.