Cary, C. University of Delaware, College of Marine Studies, caryc@udel.edu
Campbell, B. University of Delaware, College of Marine Studies, bjc@udel.edu
Cottrell, M. University of Delaware, College of Marine Studies, cottrell@udel.edu
Schmidt, M. University of Delaware, College of Marine Studies, 06601@udel.edu
Hutchins, D. University of Delaware, College of Marine Studies, dahutch@udel.edu

 
CHANGES IN BACTERIAL COMMUNITY COMPOSITION IN RESPONSE TO ADDITIONS OF FE IN 3 DIFFERENT HIGH NUTRIENT LOW CHLOROPHYLL (HNLC) REGIONS.
 
Iron limitation has been shown to affect phytoplankton growth in both open and coastal high nutrient low chlorophyll (HNLC) regions. In every HNLC area examined to date, Fe also exerts strong control over eukaryotic phytoplankton species composition, with Fe additions resulting in a switch from a nano- and picoplankton-dominated community to one composed mostly of large, ferrophilic diatom species. Fe addition also typically results in increased growth rates and abundance of heterotrophic bacteria in HNLC areas. Whether Fe also exerts control over the composition of the prokaryotic community is, however, unknown. We used molecular genetic techniques to determine the effects of Fe addition on bacterial communities from two oceanic and one coastal HNLC areas. Bacterial DNA was extracted from control and +Fe treatments in shipboard incubations carried out in the Southern Ocean, the subarctic Pacific, and along the Big Sur coast of California. Changes in the composition of the dominant members of the bacterial community during the incubation were monitored using two PCR/16S rRNA based molecular techniques; Denaturing Gradient Gel Electrophoresis (DGGE) and Terminal Restriction Fragment Length Polymorphism (T-RFLP). Comparisons of microbial communities in these treatments revealed significant changes in composition and dominance. Phylogenetic analysis of reactive members will be presented.
 
Day: Tuesday, Feb. 2
Time: 09:30 - 09:45am
Location: Hilton of Santa Fe
 
Code: SS40TU0930H