Selective plasmid transduction in Bacillus pumilus

The inducible temperate bacteriophage phi75 and a clear-plaque-forming variant, phi75C1, mediated transduction of a 4.4 X 10(6)-dalton multicopy Bacillus pumilus plasmid, pPL10, at frequencies of 10(-5) to 10(-6) transductants per plaque-forming unit. phi75- and phi75C1-mediated transduction of several chromosome markers tested did not occur at a detectable frequency. phi75-mediated plasmid transducing activity resides in particles that are similar to infectious particles in sedimentation velocity and buoyant density.