Our group explores the relationships between physiology and ecology by complementing field observations with culture-based physiological studies. We are currently investigating how temperature and the microbial community influence the marine cyanobacterium, Prochlorococcus. Prochlorococcus is the most abundant photosynthetic organism in the oceans and plays a major role in global carbon cycling. Physiologically-distinct genetic lineages of Prochlorococcus (i.e. ecotypes) partition the niche vertically by their optimizations for light levels, and latitudinally by their optimizations for temperature. In collaboration with Zackary Johnson at Duke University Marine Lab and Steven Wilhelm at the University of Tennessee, our current National Science Foundation-funded project focuses on the latitudinal partitioning by Prochlorococcus ecotypes in the North Pacific Ocean. We are seeking to improve our understanding of temperature as an ecological determinant for this important genus, and to improve our ability to predict the impact of climate change on Prochlorococcus' role in the global carbon cycle. The other major line of investigation in our group is the characterization of Prochlorococcus interactions with heterotrophic bacteria. We have discovered that co-existing heterotrophic bacteria protect Prochlorococcus from the oxidative stresses associated with life in an oxygenated, sun-lit ocean. We are using laboratory and oceanographic approaches to continue our exploration of the interactions of Prochlorococcus with other members of the microbial community.
B.A., 1994, Kenyon College
Ph.D., 2001, Harvard University
Postdoctoral Fellow, 2001-2005, Massachusetts Institute of Technology
M409 Walters Life Sciences
Knoxville, Tennessee 37996-0845
Knoxville, Tennessee 37996 | 865-974-1000
The flagship campus of the University of Tennessee System