Fig. 4.

The lag in lysis has constant concentration dependence and the lysis measured is zero order with respect to cell density. a Dependence of lag length, expressed reciprocally, on concentration at a range of temperatures, colored as previously with data at 30 °C (blue symbols/line), 33 °C (green), 35 °C (red), 37 °C (orange), and 38.5 °C (black). b Dependence of rate, v _i, on concentration at a range of temperatures, displayed by plotting logarithms to calculate the order of the reaction. Blue at A₇₀₀ = 1.52, green at A₇₀₀ = 1.67, red at A₇₀₀ = 1.80, orange at A₇₀₀ = 1.90 and black at A₇₀₀ = 2.00. In each case, rate phases A and B are fit with solid lines; the switch point, p _crit does not vary systematically with cell density. c As b for the lag length, expressed reciprocally. The dependence of lag length on concentration of pneumolysin does not alter with cell density in the range tested