Table 1.

Bacterial strains and cultures

Bacterial strain or plasmidRelevant genotype or phenotypeReference(s) or source
E. colistrains
 M15(pREP)NalsStrs Rifs LacAra Galmtl FrecA+ Uvr+26
 DB001M15 derivative containing pDB001This study
L. lactis subsp. cremorisstrains
 MG1363Plasmid-free derivative of L. lactis subsp. cremoris 7127
 UC503Isolate from Irish cheddar cheese mixed-strain starter encodingScrFI R/M activity4
 DB002MG1363 derivative containing pCI921This study
 DB003MG1363 derivative containing pCI922This study
Plasmids
 pCI3725.7-kb E. coli-L. lactissuttle vector, Cmr8
 pCI931mpBR322-based chimeric construct containing scrFIAM modification gene fromL. lactis subsp. cremoris UC503, Apr2
 pCI932mpBR322-based chimeric construct containing scrFIBM modification gene from L. lactis subsp. cremoris UC503, Apr2, 23
 pREP4Kanr, constitutively expresses thelac repressor proteinQiagen
 pQE60Ampr, IPTG-inducible expression vectoraQiagen
 pDB001pQE60 derivative containing scrFIAMThis study
 pAK80Cmr, contains promoterless β-Gal gene9
 pCI921pAK80 derivative containing promoter region upstream ofscrFIAMThis study
 pCI922pAK80 derivative containing promoter region upstream of orfXThis study
 pCI923pCI372 derivative containing scrFIAMThis study
 pCI925pCI372 derivative containing a deleted version ofscrFIAM and a deleted version of scrFIRThis study
 pCI926pCI372 derivative containing a deleted version ofscrFIR and the complete scrFIAM geneThis study
 pCI934pCI372 derivative containing orfX, scrFIBM, scrFIR, and scrFIAM24
 pCI941pCI372 derivative containing the entireScrFI locus with a deleted version ofscrFIBM24
 pCI945pCI372 derivative containingorfX and scrFIBM24
  • a IPTG, isopropyl-β-d-thiogalactopyranoside.