Isolation and Characterization of Lactic acid bacteria from homemade fermented foods for probiotic applications

Abstract

The study was conducted with the aim of isolating efficient probiotic lactic acid bacteria from traditional fermented foods viz., curd, pickle and Idly batter. A total of five lactic acid bacteria were isolated from the above mentioned naturally fermented homemade foods. Morphological and cultural characterization of the isolates revealed that they were gram positive both cocci and bacilli type having shiny straw yellow colonies and were further characterized. All the five isolates were able to utilize lactose and dextrose as a sole carbon sources. Among the LAB isolates C-1 was exhibiting the high level of inhibition zone (10 mm) against tested pathogenic Escherichia coli culture. The LAB isolates were tested for tolerance to pH and bile salt. The LAB isolate P-2 were showing growth at all the tested pH ranges (pH 2.0, 3.0 and 4.0). None of the tested LAB isolates showing tolerance to both 3 and 5 % bile salt concentration.