Characterization of a new bacteriophage which infects bacteria of the genus Acidiphilium

A novel bacteriophage, termed phi AC1, that infects strains of the genus Acidiphilium (acidophilic, heterotrophic, aerobic, Gram-negative eubacteria) most commonly isolated from acidic mine drainage environments, has been discovered and several of its properties have been determined. This is the first report of a bacteriophage infecting such cells. The virion has a lambdoid morphology and is larger than lambda, as shown by electron microscopy and sucrose gradient centrifugation. The sedimentation coefficient of the virion is approximately 615S. The nucleic acid of phi Ac1 is dsDNA, approximately 102 kb in length. Several experimental results show that phi Ac1 is a temperate phage. The plaques are turbid, and most cells isolated from plaques produced on sensitive cells by filter-sterilized phage preparations contain the phage and are resistant to further phage infection. Southern blot analysis shows that phi Ac1 prophage DNA is integrated into the bacterial genome during the temperature growth phase.