EFFECTS OF ILLUMINATION ON PLAQUE FORMATION BY ESCHERICHIA COLI INFECTED WITH T1 BACTERIOPHAGE

Abstract

Illumination of E. coli B with radiation in the range 3200-4600 A results in a slow loss of colony formation but a much more rapid loss in ability to reproduce phage. The inability to produce phage plaques is not due to a failure to adsorb phage. Illuminated bacteria which adsorb phage are killed. In these respects, E. coli strains B and B/r behave similarly. The effects of illumination are reversible and the illuminated bacteria recover their plaque-forming ability if incubated in nutrient medium after illumination but before infection.