Calorimetric study of the metabolic activity of Escherichia coli B infected by T4 phage in restricted medium

The effects of T4 phage on the metabolic rate of resting cells of Escherichia coli B in a restricted medium during the early phase of phage infection were measured calorimetrically. Heat output rate (P) and total quantity of heat (Q) of culture, heat output rate (P0) and quantity of heat (Q0) of single cell were determined. P and Q of E. coli–T4 phage system, or P0 and Q0 of infected cell, are all higher than that of control. The metabolic activity of infected cell is enhanced by 45–62%. P has a linear correlation with cell concentration (C), P (μW) = 1.68 × 10−6C (cfu/mL) + 1.86, for E. coli B cells, and for E. coli B–T4 phage system, P (μW) = 2.24 × 10−6C (cfu/mL) + 3.60. Q does not change significantly with the change of cell concentration. But Q0 decreases with C increasing, indicating that Q0 is restrained by cell density.