The rate of bacteriophage inactivation by filtrates of Eschericia coli cultures

The inactivation of bacteriophage by substances from susceptible bacteria has been studied by Burnet (1) and Freeman (2). Its inactivation by antisera has been studied by Andrewes and Elford (3) and Burnet, Keogh, and Lush (4). Recently Ashenburg et al. (5) reported that saline solutions of gum arabic, starch, or glycogen inactivated an anti-Klebsiella pneumoniae phage. We have studied in more detail the rate of phage inactivation by culture filtrates of the susceptible bacteria in order to determine the dependence of the process on phage and inhibitor concentrations.