Clark, L. L. University of Texas at Austin, Marine Science Institute, lauren@utmsi.utexas.edu
Ingall, E. L. University of Texas at Austin, Marine Science Institute, ingall@utmsi.utexas.edu
Benner, R. University of Texas at Austin, Marine Science Institute, benner@utmsi.utexas.edu

 
MARINE DISSOLVED ORGANIC PHOSPHORUS: NEW INSIGHTS FROM NUCLEAR MAGNETIC RESONANCE
 
Dissolved organic phosphorus (DOP) often dominates the dissolved phosphorus (P) pool in oligotrophic surface waters and is a potentially important source of P for sustaining marine biological productivity. Using tangential-flow ultrafiltration and 31P Nuclear Magnetic Resonance (NMR), the dominant compound classes of marine high molecular weight (HMW) DOP have been characterized in the Pacific Ocean and in cultures of four common marine primary producers (Synechococcus bacillaris, Phaeocystis sp., Emiliania huxleyi, Skeletonema costatum). In the Pacific Ocean, P esters (75%) and phosphonates (25%) were the major components identified in HMW DOP, whereas P esters were the only compound class detected in culture samples. The prominence of phosphonates in HMW DOP from the Pacific Ocean, as well as the observation that none of the cultured phytoplankton appears to produce phosphonates, is surprising. It is possible that phosphonates are present in culture HMW DOP but in concentrations undetectable by NMR, thus the relative abundance of phosphonates in HMW DOP from the Pacific Ocean could result from selective preservation during organic matter decomposition. Alternatively, phosphonates in HMW DOP could be derived from heterotrophic marine bacteria, which is consistent with preliminary data revealing the presence of phosphonates in heterotrophic bacteria.
 
Day: Tuesday, Feb. 2
Time: 12:15 - 12:30pm
Location: Eldorado Hotel
 
Code: SS34TU1215E