TABLE 1.
Bacterial strains and plasmids used in this study
All the strains obtained in this study for relevant gene deletion (Keio collection) were obtained from the Yale E. coli genetic stock center. The pQEgadE plasmid was obtained from Dr. John Foster (University of South Alabama, Mobile, AL), and the pArpoS was obtained from Dr. Udo Bläsi (University of Vienna, Vienna, Austria).
| Strain or plasmid | Relevant genotype | Source |
|---|---|---|
| Strains | ||
| HT779 | F′,Δ (araD-araB)567, ΔlacZ4787 (::rrnB-3), λ-, rph-1,Δ (rhaD-rhaB) 568, hsdR514 | Parent of Keio collection (BW25113; CGSC 7636) (33) |
| HT873 | ΔspeA ΔspeC ΔspeD ΔldcC ΔspeF ΔadiA ΔcadA | Seven sequential gene deletions of polyamine biosynthetic pathway in HT779 straina |
| HT874 | ΔspeA ΔspeC ΔspeD ΔldcC ΔspeF ΔadiA ΔcadA ΔrpoS | HT873 X ΔrpoS |
| HT875 | ΔspeA ΔspeC ΔspeD ΔldcC ΔspeF ΔadiA ΔcadA ΔgadE | HT873 X ΔgadE |
| HT894 | ΔspeA ΔspeC ΔspeD ΔldcC ΔspeF ΔadiA ΔcadA ΔrpoS/pgadE | HT874/pgadE |
| HT895 | ΔspeA ΔspeC ΔspeD ΔldcC ΔspeF ΔadiA ΔcadA ΔgadE/pgadE | HT875/pgadE |
| HT896 | ΔspeA ΔspeC ΔspeD ΔldcC ΔspeF ΔadiA ΔcadA ΔrpoS ΔgadE | HT874 X ΔgadE |
| HT898 | ΔspeA ΔspeC ΔspeD ΔldcC ΔspeF ΔadiA ΔcadA ΔclpX | HT873 X ΔclpX |
| HT901 | ΔspeA ΔspeC ΔspeD ΔldcC ΔspeF ΔadiA ΔcadA ΔrpoS/prpoS | HT874/prpoS |
| HT902 | ΔspeA ΔspeC ΔspeD ΔldcC ΔspeF ΔadiA ΔcadA ΔgadE/prpoS | HT875/prpoS |
| HT903 | ΔspeA ΔspeC ΔspeD ΔldcC ΔspeF ΔadiA ΔcadA ΔrpoS ΔgadE/prpoS | HT896/prpoS |
| HT904 | ΔspeA ΔspeC ΔspeD ΔldcC ΔspeF ΔadiA ΔcadA ΔrpoS ΔgadE/pgadE | HT896/pgadE |
| HT905 | ΔspeA ΔspeC ΔspeD ΔldcC ΔspeF ΔadiA ΔcadA ΔrpoS ΔgadE/prpoS/pgadE | HT896/prpoS/pgadE |
| Plasmids | ||
| pCP20 | FLP recombinase | Ref. 34 |
| pArpoS | rpoS overexpression | Ref. 35 |
| pQE-gadE | gadE overexpression | Ref. 29 |
a The seven genes sequentially deleted in HT873 are speC → speA → speD → cadA → ldcC → speF → adiA.