Characterization of Bacteriophage X

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Ellen Jensen


Bacteriophage X is a virus which infects certain bacteria. It was isolated during the 1970's, but was never studied. The goal of this project was to begin the initial characterization by learning about some of the basic properties of this virus. Electron microscopy revealed that Bacteriophage X had an icosahedral head and non-contractile tail which places it in the family "Siphoviridae". Degradation by DNAse indicated that the genome is composed of DNA rather than RNA. Bacteriophage X was stable in most of the chemicals in which it was tested and did not appear to have any unusual physical characteristics. The thing that made Bacteriophage X unique was its ability to infect an extremely broad range of bacteria. Normally, a bacteriophage will only infect a few strains of a species. Bacteriophage X was able to infect within four different families of gram-negative bacteria. All of these bacteria which this virus infected must have something in common which acts as the bacteriophage receptor. The nature of this receptor remains a mystery.