Microtest 96 plates

To record the phage replication and bacterial lysis, an overnight culture of the respective bacterial strain was diluted in LB Lennox media and grown to an OD at 600 nm of approximately 0.2, from which 140 μL were distributed on a 96-well plate (Microtest 96 plates, Falcon). Afterwards, 10 μL of sterile phage lysates that had previously been diluted in PBS were added to obtain a multiplicity of infection (MOI) of 1 × 10⁻² in each well. The plates were incubated in a microplate reader at 37°C with a shaking step of 30 s before the automatic recording of the OD at 600 nm every 15 min over 18 to 20 h (Tecan microplate reader). The area under the curve (AUC) was calculated in R using the trapz function from the pracma package (v2.3.3). The relative bacterial growth (RBG) was calculated using the following equation: RBG = (Abs600 [t = 4 h] − Abs600 [t = 0 h]) bp / (Abs600 [t = 4 h] − Abs600 [t = 0 h]) b, in which Abs600 represents the absorbance at 600 nm of the bacterial cultures, b represents that for bacteria only (control cultures), bp represents that for bacteria with phage (infected cultures), and t represents the time in hours (h). The RBG values were calculated at 4, 6, 8 and 10 h (22 (link)).