Figure 6.

The purification and lytic activity of the endolysin LysO78. (A) Purified LysO78. (B) Saturation curve of the endolysin LysO78 activity. The X and Y axes display the amount of endolysin added and the corresponding activity measured, respectively. Each data point corresponds to the average value of triplicate samples. The linear region was calculated by the maximalization of the determination coefficient (R²) of the linear regression, and the corresponding slope was a measure of the total endolysin LysO78 activity (units/mg). (C) The influence of pH on the lytic activity of LysO78. (D) Temperature stability of endolysin LysO78. Proteins were initially treated at different temperatures for 1 h and then the lysis activity was detected at 28 °C in buffer (50 mM Tris–HCl, 300 mM NaCl, and 10% glycerol; pH = 8.0). (E) Lytic spectrum of LysO78. In (C,E), the decrease (%) in optical density at 600 nm (OD600) = (1 − absorbance of the bacterial suspension at the end of each treatment/absorbance at the beginning of each treatment) × 100%. Each data point and associated error bars correspond to the average of triplicate samples.