Nutritional requirements for the reproduction of coliphage T2 in a strain of Escherichia coli.

The discovery of nutritional requirements for the reproduction of bacteriophage is not novel. Adams (1949) has clearly demonstrated a calcium requirement for T5 reproduction in Escherichia coli, strain B. Furthermore, Fowler and Cohen (1948) for T2 in B and more recently Gots and Hunt (1953) for X in irradiated E. coli, strain K12, have demonstrated the growth stimulating effect of certain amino acids. However, in both cases the stimulation of the growth of T2 and X was measured as an increase in burst size over the small increase consistently obtained in unsupplemented synthetic medium. In a previous note (Gross, 1952) it was reported that T2rl will not reproduce in washed and starved E. coli, strain K12, unless rather complex nutrients are added to the basal synthetic medium. In this case the effect is all or none in the sense that infected bacteria will not support any phage synthesis without the addition of essential growth factors. This conclusion is based upon the experiments described below which also indicate that certain amino acids are required for phage synthesis.