Table 4.
Efficiency of spontaneous induction of λ and ϕ24B prophages in the presence of corresponding exo–xis regions on multicopy plasmids
| Plasmid in E. coli host | Efficiency of spontaneous prophage induction (induction events per cell)a | |
|---|---|---|
| λ | ϕ24B | |
| pJW0tet (vector) | 3.2 × 10−7 ± 1.0 × 10−8 | 4.0 × 10−5 ± 3.1 × 10−7 |
| pGAW3775tet (exo–xis region of λ) | 3.2 × 10−6 ± 7.5 × 10−8 | nd |
| pSBe.x.r.ϕ24B (exo–xis region of ϕ24B) | nd | 4.4 × 10−4 ± 8.0 × 10−6 |
aMean values from three independent experiments ±SD are shown. The values were calculated considering number of infective virions appearing in the growth medium of cultures of lysogenic bacteria and average burst size of the phage estimated in one-step-growth experiments
nd Not determined