Host Range and Efficiency of Plating Determination of Phages Infecting Caulobacter and Non-Caulobacter Species

Seven bacteriophages were studied to determine their host range among Caulobacter and non-Caulobacter bacteria. Recently, Caulobacter-associated phages have been shown to have broader host ranges than previously believed. Thus, it is crucial to thoroughly verify the range of bacteria strains that these phages can infect. To understand the extent of each phage’s host range, phage lysates were spotted on bacterial lawns to determine whether lysis could occur. Host-range analyses in this project conclude that these Dolichocephalovirinae phages were able to infect multiple genera and species of host bacteria. Plating efficiency experiments were also conducted to compare the phage’s plaque-forming capabilities on their original host and the host strains within their host range. These results successfully quantified the efficiency of these phages in lysing Caulobacter and non-Caulobacter strains compared to their original host. Future research on these interactions could have important implications for agriculture, where phages could act as biocontrol agents in optimizing the rhizosphere’s microbe composition for increased agrarian productivity. Furthermore, understanding phage host ranges could have implications for clinical biocontrol applications where sterility is needed to prevent contamination. These results demonstrate how essential bacteriophages are in influencing the diversity of bacterial populations in Earth's complex environments.