NSF Postdoctoral Fellowships in Biology combine research and training components to prepare young scientists for careers in emerging areas where biology intersects with other scientific disciplines, in this case with mathematics. The Fellows are expected to lead the nation's scientific workforce of the future. This fellowship to Holly Moeller supports research and training on metabolic flexibility and marine ecosystem function. The host institution is the Woods Hole Oceanographic Institution, and the sponsoring scientists are Drs. Matthew D. Johnson and Michael G. Neubert. Training goals include coupling microbiological and modeling techniques. Educational and public outreach includes mentoring undergraduate and high school students at Woods Hole Oceanographic Institution by including them in experimental subprojects and by continuing as a scientific writer to place environmental issues in the public eye.
The research investigates the environmental selection pressures that produce mixotrophs - organisms that can fuel their metabolism through either autotrophy, i.e., photosynthesis, or heterotrophy, ingestion of organic matter. Mixotrophy is widespread in aquatic microbial communities, yet remains poorly represented in ecosystem models. The research examines, from an evolutionary perspective, how an organism maintains metabolic flexibility, rather than specializing in just one mode of nutrition, and the importance of these types of organisms to primary production, nutrient cycling, and other ecosystem functions, particularly in the ocean where climate change is likely to increase their numbers. To test the physiological limits and competitive ability of mixotrophic marine microbes, laboratory studies are being extended to modeling broader questions of eco-evolutionary dynamics.