New temperate bacteriophage for Bacillus subtilis, rho 11

Abstract

A new temperate bacteriophage, .rho.11, isolated by J. Hoch, was characterized. This new phage is very similar to the temperate phage .vphi.3T in size (380 nm), host range, homoimmunity, DNA buoyant density (1.694 g/ml), antigenicity and MW (around 6.0 .times. 107) as determined in gels. Like .vphi.3T, .rho.11 converts thymine auxotrophs to prototrophy at high frequency (250 out of 250 tested). Phage .rho.11 differs from .vphi.3T in plaque morphology and in the endonuclease R.cntdot.EcoRI digest pattern. Of the 20 .rho.11 DNA fragments, 16 have migration patterns corresponding to those of the 21 fragments of .vphi.3T. The close similarities yet clear differences between these phages suggest that the 2 phages have a common ancestor.