Figure 5. Quantifying the effects of gokushovirus carriage.

(A) Superinfection immunity offered by integrated or non-integrated phages. Unimpeded growth in the presence of infecting EC6098 phage is shown for host cultures carrying lysogenic or lysogeny-deficient EC6098. Lysis of host by EC6098 in the absence of superinfection immunity is shown in grey for comparison. Averages and standard deviations are based on three replicates. (B) Phage production by lysogenic and non-lysogenic hosts. Plaque-forming units in culture supernatant were determined from six independent cultures of BW25113 or BW25113ΔxerC, each grown overnight at 37°C from an initial concentration of OD₆₀₀ = 0.7. Box-and-whiskers plots show median, 25^th and 75^th percentiles (upper and lower hinges) and 1.5 inter-quartile range (whiskers). Outliers are shown as individual dots. P-values of <0.01 (Wilcoxon Rank-Sum test) in comparison to BW25113[EC6098] are indicated with asterisks. (C) Continuous phage production over the course of a month. Formation of plaques from supernatants of six replicate cultures of hosts carrying integrated or non-integrated phages is checked daily before 1:1000 dilution and growth for 18–24 hr at 37°C. In all cases, BW25113ΔfhuA served as the host strain for agar overlay assays.