2.6. Lysis Profile Assay

Host culture was inoculated with phage lysate at a multiplicity of infection (MOI) of 0.01. Their density was monitored by OD₆₀₀ measurement at the 30 min intervals up to 8 h. The bacterial density (OD₆₀₀), survival of host bacteria after phage infection (CFU·mL⁻¹) and lysate titer (PFU·mL⁻¹) were analyzed during the experiment. To investigate the number of surviving cells after phage infection, 100 μL samples were harvested at times indicated above, and serial dilutions (10-fold each) were made in RO medium. Then, 50 μL of each dilution was spread onto RO agar plates. The CFU of each sample was calculated by counting the colonies. To estimate the lysate titer (PFU·mL⁻¹), 100 μL samples were removed every 30 min, and their serial 10-fold dilutions were prepared in SM buffer. Then, the PFU of each dilution was calculated by counting the plaques on the bacterial lawn.