Probiotic Characteristics of Lactic Acid Bacteria Isolated from Traditional Fermented Milk ‘Dahi’ in Bangladesh

Abstract

We evaluated the probiotic characteristics (pH and acid production, acid and bile acid tolerance and Angiotensin I-converting enzyme (ACE) inhibitory activity) of lactic acid bacteria isolated from traditional fermented milk ‘Dahi` in Bangladesh. Among the tested strains, Lactobacillus delbrueckii subsp. bulgaricus M3 40-3 displayed more tolerance at acidic medium as well as highest acid production (2.13%). Whereas, highest ACE inhibitory activity (72.09±1.07%) was found in skim milk fermented with Streptococcus bovis J2 40-2. On the other hand, Lactobacillus fermentum B5 40-2 (95.53±0.79%) was exhibited strong bile acid tolerance followed by Enterococcus faecium D3 25-1 (88.66±0.76%), Lactococcus lactis subsp. lactis B4 25-3 (74.40±1.09%), Lactococcus raffinolactis D4 25-3 (72.34±1.20%) and Pediococcus pentosaceus B2 25-5 (65.67±1.58%). From the results obtained, Lactobacillus delbrueckii subsp. bulgaricus M3 40-3 might be used as probiotic starter culture for milk fermentation due to high acid production and tolerance at high acidic medium. Streptococcus bovis J2 40-2 is a unique strain detected as highest ACE inhibitory activity and suggest that it should be used as starter culture for probiotic fermented dairy foods.