Evaluation of functional traits of indigenous bacterial probiotics of North Western Himalayas

Abstract

newline Eleven indigenous probiotic bacteria obtained from traditional fermented foods of North- Western Himalayas were screened for their functional attributes including antagonistic activity against strict anaerobic pathogens viz., Clostridium perfringens, Bacteroides fragilis and Peptostreptococcus anaerobius. The growth of indigenous probiotics in selected prebiotics was maximum in lactulose followed by fructooligosaccharide and inulin. Lactic and short chain fatty acids viz., acetic, propionic and butyric were the principle metabolites observed after fermentation of prebiotics by probiotics as detected by UPLC-MS analysis. The growth of anaerobic pathogens in prebiotics was almost negligible, thereby indicating their safe use without any ill effect to the host. The antagonistic activity against strict anaerobic pathogens was analysed in cell free crude filtrates of probiotics and expressed in terms of specific activity. Maximum specific activity in crude filtrate was observed with AdF10 (L.plantarum) against C.perfringens followed by P. anaerobius and B.fragilis. The antagonistic activity present in crude filtrate was purified by ammonium sulphate precipitation and gel filtration chromatography yielding 17.88 fold increase in purification. The specific activity of crude filtrate on purification was increased from 105.26 AUmg-1protein to 1882.35AUmg-1protein against C.perfringens. The antagonistic activity was primarily mediated by proteinaceous compound(s) as the activity was lost after treatment with proteolytic enzymes. The characterization of partially purified fractions by Tris-Tricine SDS PAGE analysis revealed a wide range of proteins with molecular mass in the range of 3.5-100 kDa. The adherence of eleven indigenous probiotics was evaluated using Caco-2 and HT-29 cells as in vitro models. Among all probiotics, AdF10 (L. plantarum) was found to be the most adhesive to HT-29 and Caco-2 cell lines with % adhesion of 12.88±0.63 and 9.55±0.76, respectively, which was statistically at par with refere