A Study on Isolation of Acid and Bile Tolerance on lactic acid bacteria (LAB) in dairy product (Dahi) of Bengaluru in Karnataka

Abstract

Fermented milk products possess very important input and also plays a vital role in providing nutritional and therapeutic properties especially in dairy industries. Dahi is an indigenous and common fermented milk product of household and also has its own commercial value, prepared using lactic culture with probiotic properties. The present study was undertaken to find out the presence of acid and bile tolerance cultures for dahi samples collected from Bangalore market area. This process was carried to obtain the probiotic culture which is very much significant in the present scenario of any food and nutritional aspects of any industry related to food business. Further, the primary data were collected from different BBMP zones of Bengaluru consisting of 24 numbers of dahi samples were used for the study purpose. The results revealed that, the presence of lactococci, streptococci, leuconsotoc and lactobacilli were the major lactic acid bacterial growth. Among 82 lactic isolates, 43 isolates showed better activity in milk, acidity and DMC. Further the isolates sceening for acid and bile tolerance by adjusting the pH of the medium to 2.0 and by using 0.3% ox – bile. The maximum acid and bile tolerated isolates 12 numbers were genotypically identified as L.lactis ssp. Lactis (1) and L.lactis ssp. Lactis bv diacetylactis(1), among the 3 lactobacilli isolates L.plantarum (1), L.fermnetum (1) and L.helviticus (1) in case of leuconostocs isolates as L. mesentroides ssp. mesentroides (2) and all the streptococci as S.thermophilus (5). The purpose study is to identify the acid and bile tolerance on lactic acid bacteria and also information on identifying appropriate genotypically species of LAB which are acid and bile tolerant in nature and also boost the dairy industry in long run with these unique qualities which are very much essential for assessing the probiotic nature of particular organisms used in fermented products.