TABLE 1.

Bacterial strains, plasmids, and bacteriophages

Bacterial strain, plasmid, or phage	Relevant characteristicsa	Source or reference
Bacterial strains
L. lactis subsp. lactis
LL42-1	Wild type harboring seven plasmids	Gist-Brocades Australia
MG1363	Lac− Prt−, plasmid-free derivative of L. lactis 712	14
LM0230	Lac− Prt−, plasmid-free derivative of L. lactis C2	12
E. coli HB101	Pro− Leu− Thi− RecA−, plasmid-free	6
Plasmids
pSA3	10.2 kb; hybrid vector encoding Cmr Tcr (E. coli) and Emr (L. lactis)	9
pND801	12 kb; encoding R/M obtained from LL42-1 via coelectroporation	39
pND805	22.2 kb; R/M, pND801 cloned into the pSA3 EcoRI site	This study
Bacteriophage φ712	Small isometric-headed phage propagated on LM0230 and MG1363	14

^aLac⁻, non-lactose fermenting; Prt⁻, non-proteinase producing; Em^r, erythromycin resistance; Cm^r, chloramphenicol resistance; Tc^r, tetracycline resistance; Pro⁻, proline requiring; Leu⁻, leucine requiring; Thi⁻, thiamine requiring; RecA⁻, deficient in recombination protein.