A variety of colicinogenic factors were examined for their effect on the growth of phages related to T7. Col BI and Col B4 inhibited the growth of every phage tested. Col B2, however, did not interfere with T3 and H. Col E2 interfered only with growth of T3, while Col Ib produced abortive infection with some T7 mutants. The abortive infection associated with Col Ib seems to be correlated with the absence of the virus phosphokinase; mixed infection with T7 wild type and a phosphokinase deficient mutant was productive but the phage yield was depressed. The abortively infected cells lysed.
