Evaluation of Probiotic Characteristics of Lactic Acid Bacteria Isolated from Two Commercial Preparations Available in Indian Market

Abstract

The enormous health benefits associated with probiotics has resulted in an increased consumption of probiotic supplements. Several factors like regular subculturing, storage, unfavourable conditions etc. might compromise the efficacy and/or safety of lactic acid bacteria which are the major components of many probiotic preparations available in the market. The present study evaluated the probiotic characteristics and safety of probiotic bacteria isolated from two preparations available commercially in India. The products did not specify the genera, species or strains of the bacteria used. These were cultured using standard microbiological methods for cultivation of lactic acid bacteria. Bacteria were identified by PCR amplification and sequence analysis of 16S rRNA gene. Microbiological and molecular analyses revealed that both preparations contained homogenous population of Enterococcus faecium and Pediococcus acidilactici respectively. Assessment for several essential and desirable probiotic properties revealed that both the probiotic strains were safe and resistant to salt, lysozyme, bile salt and common antibiotics. The probiotic preparation containing P. acidilactici was better than that containing E. faecium as it survived in low pH and showed bile salt hydrolase activity. The probiotic preparation containing P. acidilactici also exhibited cholesterol-lowering activity.

Probiotic Properties of Lactic Acid Bacteria Isolated From Neera: A Naturally Fermenting Coconut Palm Nectar

“…Safety evaluation through DNase test to check for the pathogenicity of bacteria producing DNase enzyme that may cause hydrolysis of the DNA molecules was performed. Therefore, the absence of DNase in antimicrobial strains tested was confirmed to support the safety of their use in fermentations (Yadav et al, 2016; Singhal et al, 2019). The hydroxyl radical-scavenging activity of the LAB isolates is due to the colonization of viable cells and their propagation in the gut.…”

“…A tolerance to phenol was observed in the LAB isolates; this confers their natural selection in non-debittered Neera, which is naturally fermented with different microbial and chemical processes. This phenol tolerance is important for isolates to survive the gastrointestinal conditions, where the gut bacteria have the ability to deaminate aromatic amino acids that are derived from dietary proteins and may lead to formation of phenols (Yadav et al, 2016; Divisekera et al, 2019; Singhal et al, 2019). There are many instances of phenol tolerance reported in LAB that were isolated from natural fermented food sources (Ghabbour et al, 2011).…”

Lactobacillus reuteri and Enterococcus faecium from Poultry Gut Reduce Mucin Adhesion and Biofilm Formation of Cephalosporin and Fluoroquinolone-Resistant Salmonella enterica

“…The plates were incubated for 48–72 h at 37 °C and were observed for the clear zone of the DNase activity [ 34 ]. DNase activity was considered positive in the clear or pinkish zones surrounding the colonies [ 35 ]. S. aureus was used as a positive control.…”

Potential Use of Lactic Acid Bacteria with Pathogen Inhibitory Capacity as a Biopreservative Agent for Chorizo

“…In LAB, a pH < 4 is considered an inhibitory factor that affects viability due to the reduction of intracellular pH, which diffuses through the cell membrane, causing a collapse of the electrochemical gradient that has a bacteriostatic or bactericidal effect [5,30,32]. However, there are LAB that can survive at a pH < 4 and are capable passing through the digestive tract, which is a probiotic characteristic [8,16,30,34,38].…”