TABLE 1.

Strains and plasmids used in this study

Species or plasmid name	Strain	Relevant property(ies)	Reference or source
L. lactis subsp. cremoris	R1	rlt host strain	23
	R1K10	Phage-cured derivative of R1	43
	MG1363	Plasmid-free derivative of NCDO712	13
	NZ9000	Plasmid-free MG1363 derivative harboring nisK and nisR in the chromosome	9
	NZ9400	Nisin producer	9
E. coli	C41	Mutant of E. coli BL21 with enhanced tolerance for toxic proteins	28
	XL1Blue	recA1 endA1 gyrA96 thi-1 hsdR17 supE44 relA1 lac [F′ proAB laclqZΔM15 Tn10 (Tetr)]	Stratagene
pET32a		AmprE. coli expression vector containing the T7lac promoter	Novagen Inc.
pETorf11		pET32a containing orf11 cloned in frame with a thioredoredoxin moiety and a His tag	This work
pNG8048		Cmr EmrL. lactis expression vector containing the nisA promoter	Laboratory collection
pNG11		Cmr; pNG8048 containing orf11	This work