Abstract
The two phages are serologically related, but not identical. They differ in ion requirements for plaque formation on three different hosts. On Shigella paradysenteriae strain Y6R, S13 has a latent period of 14 to 15 minutes and a burst size of 200 to 250 under optimal conditions. A number of host-range and plaque-type mutants of S13 are described. Cells infected simultaneously with two different mutants release both types among the phage progeny. Less than one progeny phage per 1000, if any, is a recombinant type. Multiplicity reactivation of UV-killed S13 could not be shown. UV-killed S13 particles do not kill host cells. Photoreactivation was demonstrated. Methods for producing high-titer lysates are given.