Nitrogen (N) fixation is an ancient microbial process which evolved early in the history of our planet and is of central importance to the biosphere. All living things require fixed N for biosynthesis and N-fixing microbes in soils provide the dominant natural source of N in many terrestrial ecosystems. Despite their ancient and enduring ecological importance remarkably littleis known about the ecology and evolution of these microorganisms and of soil microbes in general. This research effort will implement a novel approach that combines stable isotope probing in concert with environmental genomics to target the genomes of non-cultivated diazotrophs. This approach will allow access to genomic DNA from these non-cultivated microbes, providing a remarkable opportunity to advance our understanding of the environmental and genomic mechanisms that regulate the diversity and activity of a microbial process of central importance to the global N-cycle. The genome sequences obtained will help shed light on the evolution of N-fixation and on genome evolution in general by revealing the complex structure of nitrogenase supraoperons in previously uncharacterized microorganisms. In addition, by using this microbial community as a model, this research will reveal basic principles pertaining to the functional significance of microbial diversity and the mechanisms that regulate microbial process in soils. Thus, this project will have both specific and far reaching effects that will improve understanding of microbial processes in the soil, and the ability to effectively manage terrestrial ecosystems.
As part of this project an educational program will be developed that is composed of three components designed to increase science literacy, to improve awareness of microbiology, and to train the next generation of environmental genomics researchers. The first component is a summer workshop "The Microbial Earth" that will provide high school science teachers with modules allowing them to implement open ended laboratory exercises in their curricula and will provide equipment and assistance to help them achieve their teaching goals. The second component is a web module called "Bioprospecting on the Frontiers of Microbiology" for the Cornell CyberTower site. This multimedia module will highlight the role of environmental genomics in discovering novel modes of life and valuable new enzymes. The last component is an advanced undergraduate course in environmental genomics to test the idea of using undergraduates in genomics cooperatives to achieve the dual goals of providing students with primary research experience while contributing to the analysis and annotation of raw genome data.
