Identification and characterization of dominant lactic acid bacteria isolated from traditional fermented milk dahi in Bangladesh

We isolated a total of 266 strains of lactic acid bacteria (LAB) from 28 dahi samples that were collected from different areas in Bangladesh. The isolated strains were identified on basis of their morphological, physiological and biochemical characteristics, the lactic acid isomer produced, the ability to ferment sugars and 16S rDNA analysis. Among the isolates, the cocci (73%) were dominant over the rods (27%). The distribution of the isolates by genus was as follows: Streptococcus (50%), Lactobacillus (27%), Enterococcus (9%), Leuconostoc (5%), Lactococcus (5%) and Pediococcus (4%). In this study, S. bovis was the most predominant species as this species represents 47.0% of the total isolates in dahi. The other species we isolated were identified as Lb. fermentum, Lb. delbrueckii ssp. bulgaricus, Lb. delbrueckii ssp. lactis, Lb. sp., Ec. faecium, S. thermophilus, Leuc. mesenteroides ssp. mesenteroides, Leuc. mesenteroides ssp. dextranicum, Lc. lactis ssp. lactis, Lc. raffinolactis and P. pentosaceus.