TABLE 3.

d-Cycloserine-based dominant selection of plasmids pGIP011 and pGIP013 in wild-type strains of L. plantarum and L. lactis^a

Organism	d-Cycloserine concn (μg/ml)	CFU	Antibiotic resistance (%)
L. plantarum	0 (+Ery)	746	100
	450	442	11
	500	264	43
	550	139	75
	600	109	96
L. lactis	0 (+Cm)	326	100
	100	>1,000	25
	150	769	96
	200	418	100

^aNumbers of primary transformants are indicated (CFU). Selection stringency depends on the concentration of d-cycloserine present in the media, as judged by replica plating to determine the antibiotic resistance phenotype of the colonies growing at different d-cycloserine concentrations (percent antibiotic resistance). Control plates without d-cycloserine contain the appropriate antibiotic. Data are representative of three independent experiments. Ery, erythromycin; Cm, chloramphenicol.