A novel sulfate-reducing bacterium (strain DePue) closely related to Desulfovibrio vulgaris ssp. vulgaris strain Hildenborough was isolated from the sediment of a heavy-metal impacted lake using established techniques. Although few physiological differences between strains DePue and Hildenborough were observed, pulse-field gel electrophoresis (PFGE) revealed a significant genome reduction in strain DePue. Comparative whole-genome microarray and polymerase chain reaction analyses demonstrated that the absence of genes annotated in the Hildenborough genome as phage or phage-related contributed to the significant genome reduction in strain DePue. Two morphotypically distinct temperate bacteriophage from strain Hildenborough were recovered using strain DePue as a host for plaque isolation.