CALCIUM ION REQUIREMENT FOR PROLIFERATION OF BACTERIOPHAGE PHI MU-4.

Shafia, Fred (University of Nebraska, Lincoln), and T. L. Thompson. Calcium ion requirement for proliferation of bacteriophage phimu-4. J. Bacteriol. 88:293-296. 1964.-Divalent ions are essential for proliferation of phage phimu-4. Small amounts of citrate interfere with efficient adsorption of phage to the host cells. Penetration of phage material into the cell is strictly dependent on divalent ions and is inhibited by low levels of citrate. Inhibition of infection can be partially reversed, in early latent period, by calcium ions. Synthesis of new phage particles is also dependent on divalent ions. Addition of citrate to infected cell suspensions significantly reduced the number of phage progeny produced. Chelates such as phosphate and citrate rapidly inactivated the free phage particles at 65 C. Chelate inactivation of phage is not reversible; however, it can be prevented to some degree by calcium ions.