김치 및 유아분변에서 분리한 유산균의 Probiotic 활성 조사

We isolated 105 strains of lactic acid bacteria (LAB) from home-made kimchi and breast milk-fed Korean infant feces on the basis of morphological analysis. This study aimed to compare the probiotic characteristics of selected strains of LAB including bile and acid tolerances, cholesterol assimilation and adhesion activity. Among the isolates of LAB, 54 isolates were identified as Lactobacillus plantarum (14 strains), L. brevis (12 strains), L. sakei (9 strains), L. acidophilus (3 strains), L. casei (1 strain), and L. fermentum (1 strain). Acid tolerances under artificial gastric juice, pH 2.5 for 2 h at 37°C, were significantly different among the Lactobacillus species. Lactobacillus acidophilus and L. plantarum strains exhibited high tolerance in acid and bile. Lactobacillus acidophilus strains exhibited high cholesterol assimilation activity and showed a significantly higher tolerance to 0.3% bile acid than other Lactobacillus strains (p<0.05). Based on these results, we selected the best strain, named NS1 (L. acidophilus) as a potential probiotics that can be utilized in the manufacturing of dairy foods and dietary supplements.