Fig. 3.

One-step growth curve for phages ϕEf11 (wild-type), ϕEf11(Δ61-1, ϕFL1C40-44) (spontaneous recombinant) and ϕEf11(vir)^PnisA (virulent variant). Exponential phase broth cultures of E. faecalis JH2-2 were infected with a phage stock. After adsorption for 30 min, the cells were collected by centrifugation, washed and incubated at 37 °C. At various time points aliquots of the suspension were centrifuged to remove the cells, and the supernatants were plaque assayed for phage titre using JH2-2 indicator cells. (•) ϕEf11 titre (p.f.u. ml⁻¹), (▪) ϕEf11(Δ61-1, ϕFL1C40-44) titre, (▴) ϕEf11(vir)^PnisA titre.