Probiotic characterization of lactic acid bacteria isolated from human milk

Abstract

The objective of this study was to evaluate the probiotic properties of lactic acid bacteria isolated from human milk. Based on biochemical characterization and 16S rRNA sequencing, the isolate was identified as Pediococcus pentosaceus DM101, the sequence of which is deposited in NCBI with accession number MK774704. Probiotic characterization in terms of acid tolerance, bile tolerance, adhesion potential, and safety of was done in vitro. Pediococcus pentosaceus DM101 was found to withstand pH 3.0 and 0.6% (w/v) bile salt for four hours. Auto-aggregation and cell surface hydrophobicity values of 68% and 60% signifies the good adhesion potential of the isolate. Inability to cause hemolysis and liquefy gelatin suggests the possible absence of virulence factors. Antibiogram revealed the isolate to be resistant to Vancomycin, Methicillin, Bacitracin, and Cephalosporin group of antibiotics. Exopolysaccharide producing nature of the isolate was confirmed by Congo red assay. DPPH assay of the cell free supernatant revealed an IC 50 value of 20.78mg/ml, endorsing its radical scavenging potential. The results obtained in this study decipher Pediococcus pentosaceus DM101 as a propitious candidate for designing foods to counteract oxidative stress proactively.