Tackling Marine Microbial Diversity


Thursday, September 8, 2011
Redfield Auditorium - 12:00 Noon
Dr. Tom Bibby
National Oceanography Centre, Southampton

Oceanic biogeochemical cycles are mediated by diverse and dynamic microbial communities. Understanding this diversity is a major challenge in modern oceanography. However, the enzymes that catalyze key biogeochemical processes are highly conserved across all taxa. Biophysical techniques (e.g. FRRF and PAM) combined with targeted molecular approaches (quantitative immunodetection) can specifically interrogate these key enzymes, giving insights to the function of diverse natural populations on spatial and temporal scales relevant to oceanography. 

We have applied these approaches in both laboratory and field studies to define: (1) the community-level molecular response of phytoplankton in oceanic regions where iron availability limits photosynthetic primary production, such as the high-latitude north Atlantic (HLNA); and (2) the molecular acclimation of the nitrogen-fixing cyanobacteria Trichodesmium to iron limitation in situ. These studies provide insights into how modern phytoplankton communities have evolved to enable the processes of photosynthesis and nitrogen fixation to proceed when iron is scarce, without modifying the conserved enzymes that catalyze these processes.