Some Technological Properties of Lactic Acid Bacteria Isolated from Dahi and Datshi, Naturally Fermented Milk Products of Bhutan

Abstract

<i>Dahi</i> and <i>datshi</i> are common naturally fermented milk (NFM) products of Bhutan. Population of lactic acid bacteria (LAB) in <i>dahi</i> (pH 3.7) and <i>datshi</i> (pH 5.2) was 1.4 × 10⁷ and 3.9 × 10⁸ cfu/ml, respectively. Based on 16S rRNA gene sequencing isolates of LAB from <i>dahi</i> and <i>datshi</i> were identified as <i>Enterococcus faecalis, E. faecium, Lactococcus lactis</i> subsp. <i>lactis.</i> LAB strains were tested for some technological properties. All LAB strains except <i>E. faecalis</i> CH2:17 caused coagulation of milk at both 30°C for 48 h. Only <i>E. faecium</i> DH4:05 strain was resistant to pH 3. No significant difference (<i>P</i> > 0.05) of viable counts was observed in MRS broth with and without lysozyme. All LAB strains grew well in 0.3% bile showing their ability to tolerate bile salt. None of the LAB strains showed >70% hydrophobicity. This study, being the first of its microbiological analysis of the NFM of Bhutan, has opened up to an extent of research work that gives a new insight to the products.