Bacteriophage T2r+ Infection

The activities of six bacteriophage T2r+-induced enzymes (thymidylate synthetase, deoxycytidylate deaminase, thymidylate kinase, deoxycytidylate hydroxymethylase, deoxycytidine pyrophosphatase, and dihydrofolate reductase) were measured after dilution of phage-infected Escherichia coli B from 8 X 108 to 2 x 108 cells per ml. The only enzyme activity altered was that of deoxycytidylate deaminase, which increased threeto fourfold. Conversely, the rapid concentration of cells from 2 X 108 to 8 X 108 per ml did not result in a reduction in deaminase activity. Although an enhancement in aeration reduced the response of deoxycytidylate deaminase to cellular dilution, the influence of potential metabolic inhibitors or activators could not be shown. The change in deoxycytidylate deami-