Ouverney, C. C. University of Southern California, ouverney@usc.edu
Fuhrman, J. A. University of Southern California, fuhrman@usc.edu

 
SIMULTANEOUS IN SITU MEASUREMENTS OF SPECIFIC NUTRIENT UPTAKE BY SPECIFIC MARINE BACTERIAPLANKTON CELLS
 
Current in situ measurements of marine bacterioplankton DOM uptake includes the total prokaryotic community. Molecular data, however, show that the marine bacterioplankton is made of very diverse groups. Since nutrient uptake by pure culture prokaryotes varies among groups, we can assume that in situ DOM uptake is dependent on the local bacterioplankton community composition. We are interested in the ecological contribution of specific marine prokaryotic subgroups to nutrient uptake in the ocean. We have proposed a new method to "dissect the bacterioplankton blackbox" into smaller subgroups with group-specific fluorescent molecular probes and simultaneously determine the nutrient uptake by each one of the subgroups with a 3H-nutrient via autoradiography. The technique combines FISH and autoradiography on a single slide to determine the % of the different subgroups in the community, the % of total cells in the community that take up the radioactive nutrient, and the distribution of nutrient uptake within each subgroup. Here, we present the preliminary results from in situ nutrient uptake measurements by marine Bacteria, Archaea, Cytophaga-Flavobacteria, alpha-Proteobacteria, and SAR 11 subgroups for samples along Southern California, USA, and the French Mediterranean.
 
Day: Tuesday, Feb. 2
Time: 02:45 - 03:00pm
Location: Sweeney Center
 
Code: SS41TU0245S