Phage Formation in Staphylococcus Muscae Cultures Ix. Effect of Multiple Infection on Virus Syntbesis in the Absence and Presence of Specific Substrates by Winston

In the preceding paper (1) it was found that some strains of S. muscae required the addition of a substance found in certain acid-hydrolyzed proteins (AHPF) to liberate phage in Fildes' synthetic medium when singly infected with virus. Another strain required aspartic acid to liberate phage in Fildes' synthetic medium when singly infected. Experiments reported in this paper show that such strains do not need the AHPF or aspartic acid to liberate phage when infected with more than two phage particles per cell. An analysis of this phenomenon has indicated that this result is not due to the presence of cells which do not require the ARPF or aspartic acid when singly infected, or to the presence of phage for which the AHPF or aspartic acid is not a necessary component for synthesis. Further experiments indicated that the phage particle itself was the active substance in the lysate capable of replacing the AHPF and aspartic acid. Other experiments showed that an acid hydrolysate of purified phage could replace the AHPF; hence it appears as if the AHPF is a constituent of the phage. The preceding paper showed that aspartic acid is also a constituent of the virus (1).