Assessment of anti-biofilm activity and bifidogenic growth stimulator (BGS) effect of lyophilized exopolysaccharides (l-EPSs) from Lactobacilli strains

Figures & data

Table 1. Origin and molecular identification results of lactobacilli in this study by sequencing the 16S rRNA gene region of lactobacilli in this study.

Strain	Origin	Identity%	GenBank accession number
Lactobacillus fermentum LB-69	Feces	99	JQ013298.1
Lactobacillus rhamnosus GD-11	Feces	99	AB008211.1
Lactobacillus casei LB-8	Feces	100	JQ0466411.1
Lactobacillus plantarum GD-2	Feces	99	AB112083.1
Lactobacillus delbrueckii ssp. bulgaricus A-12	Milk product	100	AY735407.1
Lactobacillus delbrueckii ssp. bulgaricus B-3	Milk product	99	FJ915697.1

Table 2. The amount and carbohydrate composition of l-EPS isolated from lactobacilli and carbohydrate composition of l-EPSs.

		Monosaccharides (%)
Strains	Quantity of l-EPS (mg/L)	Mannose	Glucose
L. fermentum LB-69	310 ± 2	96.00	4.00
L. rhamnosus GD-11	320 ± 4	95.96	4.04
L. paracasei ssp. paracasei LB-8	255 ± 5	93.20	6.80
L. plantarum GD-2	270 ± 5	88.20	11.80
L. delbrueckii ssp. bulgaricus A-12	286 ± 6	82.80	17.20
L. delbrueckii ssp. bulgaricus B-3	286 ± 3	91.20	8.80

Table 3. Effect of l-EPS on Bifidobacterium breve BASO-1 development.

Strain	Bifidobacterium breve BASO-1 Viable count (log cfu/mL)
	0.5 mg/mL	1 mg/mL
L. fermentum LB-69	9.91 ± 1.20	10.70 ± 1.02
L. rhamnosus GD-11	10.10 ± 1.05	10.59 ± 1.89
L. paracasei ssp. paracasei LB-8	9.79 ± 1.89	10.50 ± 1.16
L. plantarum GD-2	9.69 ± 1.20	10.35 ± 1.84
L. delbrueckii ssp. bulgaricus A-12	9.60 ± 1.84	10.00 ± 1.10
L. delbrueckii ssp. bulgaricus B-3	9.60 ± 1.50	10.10 ± 1.78
Inulin (positive control)	9.49 ± 1.55	9.98 ± 1.55
Negative control (without l-EPS)	9.31 ± 1.35	9.31 ± 1.35

Figure 1. EPS fermentation by Bifidobacterium breve BASO-1. (1) The viability in MRS-C medium. (2) The viability in carbohydrate-free basal medium with 1% (wt/vol) l-EPS.

Table 4. Biofilm formation of some pathogenic bacteria.

Strains	Biofilm
B. cereus RSKK 863	+++
L. monocytogenes ATCC 7644	+++
E. fecalis ATCC 25175	+++
P. aeruginosa ATCC 72853	+++
E. coli 0157:H7	++
E. coli ATCC 35218	++
S. aureus EB-1	+
S. aureus ATCC 25923	+
S. aureus EB-12	+
S. aureus ATCC 2392	+
S. aureus EB-36	+
S. aureus EB-18	+
S. typhimurium BAST-01	+

+++: Strong biofilm formation.

++: Middle biofilm formation.

+: Weak biofilm formation.

Table 5. Anti-biofilm activity of lyophilized EPSs from the exopolysaccharide (EPS)-produced lactobacilli strains.

Inhibition of biofilm (%)
	LB-69		GD-11		B-3
Strains	0.1 mg/mL l-EPS	1 mg/mL l-EPS	0.1 mg/mL l-EPS	1 mg/mL l-EPS	0.1mg/mL l-EPS	1 mg/mL l-EPS
L. monocytogenes ATCC 7644	50	88	36	83	21	76
E. fecalis ATCC 25175	47	85	30	87	15	75
B. cereus RSKK 863	55	90	38	83	20	78
P. aeruginosa ATCC 72853	52	88	36	85	18	74