Table 1.

Bacterial strains, phages, and plasmids used in this studya

Strain, plasmid, or phageDescriptionSource or reference
Strains
L. rhamnosus7469Formerly named L. casei ATCC 7469ATCC
L. casei102S L. casei ATCC 393 cured from plasmidsB. Chassy
L. casei 102SdltD::erm Emr; dltDinterrupted by erm This study
E. coliXL-1 Blue MRF′Δ(mcrA) 183Δ (mcrCB-hsdSMR-mrr) 173end1A supE44thi-1 recA1 gyrA96 relA1lac [F′ proAB lac q ZΔM15 Tn10(Tetr)]Stratagene
E. coli BL21(DE3) pLysSF ompT hsdSB (rB mB ) gal dcm(DE3)pLysSNovagene
E. coli DH5αFf80dlacZΔM15 Δ(lacZYA-argF)U169 deoR recA1 endA1 hsdR17(rk mk +) supE44 λ thi-1 girA96 relA1 Gibco-BRL
Phages (phagemids)
 λZAPII [Bluescript SK()]Aprcloning vectorStratagene
 VCSM13Helper phageStratagene
 λZAPII(−)DE434.3 kb of L. rhamnosus DNA containing dltA, dltB, dltC, and partial dltD 10
 λZAPII(−)A656.5 kb of L. rhamnosus DNA containing partial dltB, dltC, dltD, and downstream flanking regionThis study
Plasmids
 pET-3dExpression vectorNovagene
 pDltDExpression plasmid; dltD cloned into pET-3dThis study
 pΔDltDExpression plasmid; ΔdltD cloned into pET-3dThis study
 pVE6006Emr CmrTs shuttle vector 30
 pNZ123Cmr shuttle vector 46
 pΔDltD/erm 1.2-kb EcoICRerm fragment of pVE6006 joined to BamHI blunt-ended pΔDltD in direct orientation to ΔdltD This study
 pNZ123/dlt 4.895-kb fragment containingdlt operon cloned into HindIII of pNZ123This study
  • a Emr, erythromycin resistant; Cmr, choramphenicol resistant; Apr, ampicillin resistant; ATCC, American Type Culture Collection.