THE ROLE OF RESISTANCE TO BILE SALTS AND ACID TOLERANCE OF EXOPOLYSACCHARIDES (EPSS) PRODUCED BY YOGURT STARTER BACTERIA

Boke H., ASLIM B., Alp G.

ARCHIVES OF BIOLOGICAL SCIENCES, cilt.62, sa.2, ss.323-328, 2010 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 62 Sayı: 2
  • Basım Tarihi: 2010
  • Doi Numarası: 10.2298/abs1002323b
  • Dergi Adı: ARCHIVES OF BIOLOGICAL SCIENCES
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.323-328
  • Anahtar Kelimeler: EPS, Lactobacillus delbrueckii bulgaricus, Streptococcus thermophilus, bile salt resistance, acid tolerance, DNA RESTRICTION ANALYSIS, DAIRY PROPIONIBACTERIA, LACTOCOCCUS-LACTIS, IN-VITRO, CULTURES, STRAINS
  • Gazi Üniversitesi Adresli: Evet

Özet

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 EPS 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 %).