This project presents an integrated, comprehensive research and training program that focuses broadly on the topics of environment and energy - through its focus on important fundamental and applied aspects of research on natural photosynthesis. The research will be conducted jointly in the laboratories of Co-PIs Donald A. Bryant and John H. Golbeck, who have collaborated on research in natural photosynthesis for more than twenty years. The central "paradigm" of this project derives from research to understand the structural and functional details of type-1 photochemical reaction center (RCs) of Cyanobacteria. The potential impact of the work in terms of significance to the environment includes the biochemical characterization a newly discovered, oxygen-tolerant homodimeric Type-1 RC (Aim 1); determining the functional, environmental, and potentially evolutionary relevance of multiple copies of genes encoding Photosystem I (PS I) subunits in an iron-loving cyanobacterium, (Aim 2); conducting studies of cyanobacterial thylakoid membrane and PS I biogenesis using conditionally controlled gene expression in the model cyanobacterium Synechococcus sp. PCC 7002 (Aim 3). The potential impact of the project in terms of significance to solar energy involves characterizing the dynamics of primary charge separation in PS I (Aim 4). The application of knowledge gained from the studies proposed herein, as well as those conducted during more than 20 years of NSF-supported research by the Co-PIs, is evident in the proposed development of a PS I-molecular wire construct to serve as a light-driven, electron-injection device to study the mechanisms of proton-coupled, electron transfer reactions in redox-active enzymes (Aim 5). The successful completion of this research program will significantly increase an understanding of the mechanism of primary charge separation in type-1 RCs and should also provide instructive new insights for the future development of devices to perform solar energy capture and conversion. There are excellent reasons to believe that it may be possible to identify an inorganic catalyst that is synthesized biologically and that would mimic the Fischer-Tropsch reaction but generate C-C bonds at 298 K and 1 bar.
Broader Impacts
This research program is designed to present outstanding training opportunities that will allow the Co-PIs to co-mentor graduate and undergraduate students in topics that include microbial ecology, physiology, genetics, genomics, biochemistry, and biophysics. One reason for merging these research programs into a single program was to provide broader, better integrated training to students, whom will thus be able to think more globally about issues concerning energy and the environment. The aims of this proposal were similarly organized in such a way to illustrate how these projects progress logically from studies with their origins in microbial ecology and the environment to those that are firmly based in biochemistry and biophysics. Based upon their combined, broad research interests and perspectives in natural photosynthesis, light harvesting, and solar energy conversion processes, the Co-PIs will help to train the next generation of academic and industrial scientists in a field that is growing in importance to the strategic interests and long-term economic prosperity of our society. The Co-PIs will continue their extensive involvement in outreach and synergistic relationships in science. Important aspects of this effort include a commitment to involving both faculty and students at exclusively or predominantly undergraduate institutions in our research program. The Co-PIs are committed to continuing their current training of students who are members of underrepresented minorities in science. Finally, outreach and educational activities at the high school and grade school levels are planned.
