TABLE 1.

Bacterial strains and plasmids used in this study

Strain or plasmid	Relevant characteristicsa	Reference
Strains
Lactococcus lactis
NIZO B40	Lac+ Eps+	33
MG1614	Rfr Smr, plasmid free	12
NZ4010	MG1614 derivative containing pNZ4000	33
NZ9000	MG1363 pepN::nisRK	20
E. coli MC1061		6
Plasmids
pNZ4000	40-kb plasmid bearing genes for EPS production	33
pNZ4030	Emr, 27-kb derivative of pNZ4000	33
pNZ4040	Cmr, plasmid with the marker gene gusA under control of the eps promoter	33
pNZ8048	Cmr, lactococcal cloning and expression vector with the nisA promoter upstream of a multiple cloning site	20
PNZ4150	pNZ8048 derivative containing the E. coli fbp gene translationally fused to the nisA promoter	This work

^aLac⁺, lactose-fermenting phenotype; Eps⁺, EPS-producing phenotype; Rf^r, rifampin resistant; Sm^r, streptomycin resistant; Em^r, erythromycin resistant; Cm^r, chloramphenicol resistant.