Probiotic attributes of indigenous Lactobacillus spp. isolated from traditional fermented foods and beverages of north-western Himalayas using in vitro screening and principal component analysis.

Abstract

The present research was designed to explore indigenous probiotic Lactic acid bacteria from traditional fermented foods and beverages of North-western Himalayas for their probiotic potential. It was achieved through a step-by step approach focused on the technological characterization, evaluation of the probiotic traits and adherence ability. Fifty one LAB isolates from traditional fermented foods and beverages were initially screened for their technological properties and among them twenty isolates were selected. These isolates were further characterized and identified using 16S rRNA gene sequencing as Lactobacillus brevis (7 isolates), Lactobacillus casei (5), Lactobacillus paracasei (2), Lactobacillus buchneri (1), Lactobacillus plantarum (1) and Lactobacillus sp. (3). Identified isolates were evaluated by in vitro methods including survival in gastrointestinal tract, antibiotic susceptibility, antimicrobial activity, cell surface characteristics, exopolysacharride production and haemolytic activity. The results of these experiments were used as input data for Principal Component Analysis; thus, to select the most promising probiotic isolates. Three isolates (L. brevis PLA2, L. paracasei PLA8 and L. brevis PLA16) were found to be most technological relevant and promising probiotic candidates in comparison to commercial probiotic strains. L. brevis PLA2 was selected as best isolate with probiotic potential by in vitro adherence to the human intestinal HT-29 cell line.