The role of resistance to bile salts and acid tolerance of exopolysaccharides (EPSS) produced by yogurt starter bacteria

Hatice Boke, Belma Aslim, Gulcin Alp
2010 Archives of Biological Sciences  
The aim of this study was to investigate a possible relation between EPS production and resistance to bile salts and tolerance to low pH. Eight strains which produced the highest and lowest amount of EPS (16-211mg/l) were selected among 54 bacteria isolated from yogurt. Additionally, they were tested for resistance to bile salts (0.15, 0.3 %) and tolerance to low pH (2.0-3.0). After treatment with bile salts and acid, viable bacteria (log cfu ml-1) were determined by surface plating. The high
more » ... S producing strains (B3, G12, W22) showed a significant (P<0.05) protective effect against low pH (pH 2.0). All Streptococcus thermophilus strains showed a higher tolerance to bile salts than the Lactobacillus delbrueckii subsp. bulgaricus strains. The high EPS-producing S. thermophilus (W22, T12) and L. bulgaricus (B3, G2) strains showed a significant (P<0.01) protective effect against bile salts (0.3 %).
doi:10.2298/abs1002323b fatcat:nbhf5bd44jfmbdd4kmnprh4yhq