Exploring the World of Phages with Dora and Explorer

Bacteriophages, commonly known as phages, are viruses that infect bacteria cells. Although they are invisible to the naked eye, phages are thought to outnumber bacterial cells by a factor of ten creating a wide diversity among them. This large population of phages provides us with ample opportunities to explore the diversity of phages locally. For this project we sought to determine whether aqueous phages that infect Rhodobacter capsulatus can be found in Bloomington and if so, how are they related to one another. To test this, we acquired water samples from Miller and White Oak Parks and were able to both isolate phages that infect R. capsulatus. Both phages, RcDora and RcExplorer, underwent several tests to determine the characteristics of each virus. Transmission Electron Microscopy (TEM) analysis allowed us to calculate the sizes of their capsids and tail lengths which were found to be similar for both phages. Polymerase Chain Reaction (PCR) tests further suggested that both may be members of the RcD cluster. Ultimately full sequencing of their genomic DNA revealed that these two phages have a 99% match rate between their genomes indicating that while they are highly related, they are not identical. The research we performed has now added two new unique RcD phages to the growing collection at IWU. This continues to make this cluster the most highly represented in the collection but also helps to provide insight into viral diversity and evolution