TABLE 2.

Transformation efficiency and stability of pRV566 in lactobacilli

Recipient strain	No. of endogenous plasmids	Transformability with pRV566 with DNA prepared froma:		Stability of pRV566 with the indicated no. of generations without selective pressureb
		E. coli TG1	L. sakei 23K	20	40	60	80	100
L. sakei ATCC15521	≥2c	3 × 101	2 × 101	100	95	100	90	95
L. sakei G3AF	1c,d	0 (8 × 105)h	0
L. sakei 160K	0d	1.8 × 104	2.4 × 104	75	60	35	20	10
L. sakei RV332	1c	4.2 × 105	1.2 × 104	85	70	75	60	65
L. sakei 23K	0d	3.1 × 105	1.4 × 106	95	85	60	40	20
L. sakei 64F	1d,e	1 × 101 (1.4 × 105)g	2 × 101	90	95	85	70	30
L. plantarum ATCC 8014	>3	4 × 101 (3.6 × 104)g		90	90	65	55	30
L. plantarum ATCC 14917	2	0 (5.7 × 103)h
L. curvatus ATCC 20019	0	0 (1.1 × 104)h
L. curvatus 116	≥3c	0 (0)g,h
L. curvatus T402	>4c	0 (1.1 × 104)h
L. curvatus T411	0	1 × 102		75	90	75	70	20
L. casei BL23	0f	>105		90	40	20	15	10

^aExpressed as the number of erythromycin-resistant CFU per μg of DNA after electroporation.

^bExpressed as the ratio (%) of erythromycin-resistant CFU scored after growth for the indicated number of generations and corrected to the nearest 5%.

^cAt least one of the plasmids strongly hybridized with pRV566.

^dBerthier et al. (6).

^eLangella et al. (33).

^fGosalbes et al. (23).

^gFor comparison, the transformation efficiency obtained with replicative plasmid pGhost4 is indicated in parentheses.

^hFor comparison, the transformation efficiency obtained with replicative plasmid pIL253 is indicated in parentheses.