TABLE 1.
Strains and plasmids used in this study
| Strain or plasmid | Genotype or description | Reference or source |
|---|---|---|
| L. lactis strains | ||
| MG1363 | Plasmid-free and prophage-cured derivative of NCDO712 | 16 |
| NZ3900 | MG1363 derivative, used as wild-type control (ΔlacF pepN::nisR-nisK) | 12 |
| PH3960 | NZ3900 derivative carrying a deletion in alr (Δalr) | This study |
| GB3960 | PH3960 derivative carrying a deletion in acmA (Δalr acmAΔ1) | This study |
| MG1363acmAΔ1 | MG1363 derivative carrying a deletion in acmA (acmAΔ1) | 9 |
| MG1363 (dltD) | MG1363 derivative carrying an ISS1 insertion in dltD (dltD::ISS1) | 13 |
| MG1363 (dltD acmAΔ1) | MG1363 (dltD) derivative carrying a deletion in acmA (dltD::ISS1 acmAΔ1) | This study |
| NZ9000 | MG1363 pepN::nisRK | 30 |
| NZ9700 | Nisin producing transconjugant of NZ9000 containing the nisin-sucrose transposon Tn5276 | 29 |
| Plasmids | ||
| pINTAA | Integration plasmid used for the introduction of a 701-bp deletion in acmA; Emr | 9 |
| pGIP011 | PJDC9 derivative containing an internal fragment of alr from MG1363; Emr | 23 |
| pGIP016 | PGIP011 derivative containing an in frame deletion of alr from MG1363; Emr | This study |
| pNG3041 | Plasmid used for the nisin induced overexpression of MSA2cA; Cmr | Laboratory collection |