Characterisation and probiotic potential of lactic acid bacteria isolated from Iranian traditional yogurts

Figures & data

Figure 1. 16S rDNA PCR products (757 bp): Lane M: 100 bp DNA marker; Lane P: positive control; Lane N: negative control; Lanes 1–12: LAB isolates.

Table 1. Acid and bile acid tolerance of the LAB isolates.

LAB specification			Acid tolerance (pH 2.0)		Bile tolerance^a
Isolate	ID	Yogurt	h0	h3	Cinh
Lb. brevis	86	Sheep	2.1 × 10^9	3.1 × 10^8	0.34
Lb. brevis	25	Goat	1.1 × 10^9	2.2 × 10^8	0.02
Lb. fermentum	27	Goat	3.4 × 10^9	3.1 × 10^9	0.05
Lb. kefir	13	Goat	1.4 × 10^9	1.5 × 10^8	0.24
Lb. plantarum^b**	90	Sheep	1.8 × 10^9	4.1 × 10^7	0.25
Lb. plantarum^b**	78	Sheep	1.4 × 10^9	1.3 × 10^8	0.13
P. acidilactici	92	Goat	2.2 × 10^9	1.4 × 10^8	0.38
P. acidilactici	23	Sheep	2.1 × 10^9	1.1 × 10^7	0.4
P. acidilactici	50	Cow	1.2 × 10^9	2.0 × 10^7	0.09
P. acidilactici	51	Cow	1.5 × 10^9	1.6 × 10^6	0.04
P. acidilactici	72	Cow	1.9 × 10^9	1.6 × 10^9	0.01
P. acidilactici	74	Cow	1.7 × 10^9	1.3 × 10^8	0.06

Each value represents mean ± SD from two trials (log CFU/ml);

^a 0.3%, h8;

^b subsp. plantarum.

Table 2. Susceptibility of the LAB isolates to antibiotics using disc diffusion method.

			Antibiotic
Isolate	ID	Yogurt	CHL	CLI	ERY	GEN	PEN	RIF	STR	TET	VAN
Lb. brevis	86	Sheep	M	S	S	S	S	S	R	S	R
Lb. brevis	25	Goat	R	S	S	S	R	S	R	R	R
Lb. fermentum	27	Goat	M	S	S	S	S	S	R	S	R
Lb. kefir	13	Goat	R	S	S	M	M	S	R	R	R
Lb. plantarum^a	90	Sheep	M	S	S	S	S	S	R	S	R
Lb. plantarum^a	78	Sheep	R	S	S	S	R	S	R	R	R
P. acidilactici	92	Goat	R	S	S	S	S	S	R	R	R
P. acidilactici	23	Sheep	R	S	S	S	S	M	R	R	R
P. acidilactici	50	Cow	R	S	S	S	S	S	R	R	R
P. acidilactici	51	Cow	R	S	S	S	S	S	R	M	R
P. acidilactici	72	Cow	R	S	S	S	S	S	R	S	R
P. acidilactici	74	Cow	R	S	S	S	S	M	R	R	R

CHL: chloramphenicol (30 μg); CLI: clindamycin (2 μg); ERY: erythromycin (15 μg); GEN: gentamicin (10 μg); PEN: penicillin G (10 μg); RIF: rifampicin (5 μg); STR: streptomycin (10 μg); TET: tetracycline (30 μg); VAN: vancomycin (30 μg). R: resistant; M: moderate susceptible; S: susceptible; ^asubsp. plantarum.