FIG. 6.

Effects of γ-PGA capsule on growth of phages with or without PghP. B. subtilis NAFM5 was shaken in GSP medium (22) at 37°C. When the optical density at 600 nm of the cultures reached 0.3 (noncapsulated [open circles]) or after 24 h (encapsulated stationary phase [closed circles]), phages ΦNIT1 (PghP⁺) (A) and BS5 (PghP⁻) (B) were added at concentrations of 10⁴ PFU/ml and incubation was continued at 37°C. Purified PghP (1 μg/ml) was added to stationary-phase cultures together with BS5 (closed triangle). After indicated periods, phages in cultures were titrated against strain NAFM5 as the indicator.