Kinetics of bacteriophage release by single cells of φX174-infected E. coli

The mechanism of release of φX174 by infected E. coli is of interest since its understanding must result in the discovery of either: (1) a phage-specific lytic enzyme (Streisinger, Mukai, Dreyer, Miller & Horiuchi, 1961; Jacob & Fuerst, 1958) which would be the first example of a φX-specific enzyme; or (2) a novel method of phage release. Recently some unsuccessful attempts to detect a lytic enzyme in the mature phage particle and in infected cells have been reported (Fujimura & Kaesberg, 1962; Eigner, Stouthamer, Van der Sluys & Cohen, 1963). It has been suggested (Eigner et al., 1963) that release of φX precedes cellular dissolution. Denhardt (1963, in preparation) has shown that even when the infection process is synchronized by infection in the presence of 0·003 M-KCN or by 'infection of starved cells phage release occurs over a period of time longer than the minimum latent period. These results suggested the possibility that ,PX might be released slowly from single infected complexes, as is the case with certain animal viruses (see, for example, Dulbecco & Vogt, 1954), rather than in bursts occurring at the time of lysis.