Biodiversity of Aquatic Phage

San Diego State University Foundation, San Diego CA

Investigators

Abstract

Phage, viruses that kill bacteria, are the most abundant biological entities on the planet. They have major influences on global carbon, nitrogen, and phosphorous cycling. By killing specific bacterial hosts, phage help maintain microbial diversity and they are major conduits of genetic exchange. Additionally, phage are major sources of economically important enzymes for industrial and biotech applications. Despite their importance to global ecology, almost nothing is known about phage biodiversity or biogeography because less than 1% of them can be cultured. Therefore, environmental phage communities are one of the largest unexplored reservoirs of sequence diversity on the planet. This project will utilize genomic sequencing to examine the diversity and distribution of uncultured phage in all of the world's major aquatic environments. The types of phage present within an environment, as well as the population structure (i.e., the number of different phage genomes present and their relative abundances) will be determined. The global distribution of specific phage sequences will be examined in order to assess the extent of phage movement between environments; gene transfer among phage will also be explored. This work will lead to the identification of the world's most common phage types and produce population models of phage in major aquatic systems. In turn, this knowledge will allow for better predictions about how the environment will respond to global climate changes. Comparing phage populations from different aquatic environments will lead to new paradigms about the factors that govern the biogeographical distributions and ecology of environmental phage. In addition, results from this project will be used to evaluate and expand upon current phage taxonomy systems, which are of great value to the scientific community. Enzymes of interest to biotech industries will also be identified and characterized during this project. Finally, this research will result in the sequencing of complete genomes of biologically important uncultured phage from aquatic environments. Undergraduate and graduate students, including a number of underrepresented minorities, will receive training during the course of these studies.