TABLE 1.
Strains and plasmids used in this study
| Strain or plasmid | Relevant characteristicsa | Source or referencea |
|---|---|---|
| Strains | ||
| L. brevis ATCC 8287 (GRL1) | ATCC | |
| L. lactis MG1363 | Plasmid-free derivative of NCDO 712, Lac− | 12 |
| L. lactis NZ9000 | pepN::nisR nisK | 9 |
| L. lactis LL108 | RepA+ MG1363, Cmr, carrying multiple copies of the pWV01 repA gene in the random chromosomal fragment A | 25 |
| L. brevis GRL1045 | Emr Cms, derivative of GRL1 with the c-Myc epitope insert in the genomic slpA and unintegrated pKTH5115 | This study |
| L. brevis GRL1046 | Emr Cms, derivative of GRL1 with the c-Myc epitope insert in the genomic slpA | This study |
| Plasmids | ||
| pLET1 | Cmr Kmr, lactococcal expression vector with T7 RNA polymerase promoter | 55 |
| pKTH 2151 | Cmr Kmr, pLET1 derivative carrying the L. brevis slpA gene | This study |
| pKTH2152 | Cmr Kmr, pKTH 2151 derivative; slpA fused with a poliovirus VP1 epitope insert in insertion site I | This study |
| pNZ8032 | Cmr, pNZ8008 derivative carrying the gusA gene translationally fused to the nisA promoter (PnisA) | 10 |
| pNZ9530 | Emr, nisRK cloned in pIL252, expression of nisRK driven by rep readthrough | 19 |
| pKTH5006 | Cmr, pNZ8032 derivative carrying the slpA gene under PnisA; the VP1 epitope encoding nucleotides in slpA insertion site I | This study |
| pKTH5007 | Cmr, as pKTH5006, the VP1 insert in slpA insertion site II | This study |
| pKTH5008 | Cmr, as pKTH5006, the VP1 insert in slpA insertion site III | This study |
| pKTH5063 | Cmr, as pKTH5006, the VP1 insert in slpA insertion site IV | This study |
| pKTH5074 | Cmr, as pNZ8032 derivative carrying the slpA gene under PnisA; slpA fused with c-Myc epitope encoding nucleotides in slpA insertion site II | This study |
| pVE6007 | Cmr, ts derivative of pWV01 | 29 |
| pORI280 | Emr, lacZ+ ori+ derivative of pWV01, replicates only in strains providing RepA in trans | 25 |
| pKTH5115 | Emr, pORI280 derivative with slpA lacking its promoters, RBS, and transcription terminator and carrying the c-Myc | This study |
a
Cmr, resistance to chloramphenicol; Kmr, resistance to kanamycin; Emr, resistance to erythromycin; ATCC, American Type Culture Collection.