Effects of metabolic inhibitors on the assembly of fd phage

Treatment of E. coli cells that are actively producing fd phage with KCN, arsenate, DNP or CCCP inhibits production of infectious phage. These results are consistent with (but do not prove) an energy dependence for the assembly of fd phage. The major difficulty is to distinguish between a direct dependence on the proton motive force and an indirect one. Very preliminary experiments with valinomycin, which can be used to manipulate the voltage gradient of the cell membrane, and nigericin, which can be used to alter the pH gradient, suggest that a voltage gradient is not required for phage assembly but that pH gradient is required.