Identification and Characterization of Lactic Acid Bacteria in a Commercial Probiotic Culture

Abstract

The aim of the present study was to describe the identification and characterization (physiological properties) of two strains of lactic acid bacteria (LAB 18 and 48) present in a commercial probiotic culture, FloraMax®-B11. Isolates were characterized morphologically, and identified biochemically. In addition, the MIDI System ID, the Biolog ID System, and 16S rRNA sequence analyses for identification of LAB 18 and LAB 48 strains were used to compare the identification results. Tolerance and resistance to acidic pH, high osmotic concentration of NaCl, and bile salts were tested in broth medium. In vitro assessment of antimicrobial activity against enteropathogenic bacteria and susceptibility to antibiotics were also tested. The results obtained in this study showed tolerance of LAB 18 and LAB 48 to pH 3.0, 6.5% NaCl and a high bile salt concentration (0.6%). Both strains evaluated showed in vitro antibacterial activity against Salmonella enterica serovar Enteritidis, Escherichia coli (O157:H7), and Campylobacter jejuni. These are important characteristics of lactic acid bacteria that should be evaluated when selecting strains to be used as probiotics. Antimicrobial activity of these effective isolates may contribute to efficacy, possibly by direct antimicrobial activity in vivo.

Evaluation of a Probiotic and a Competitive Exclusion Product Inoculated In Ovo on Broiler Chickens Challenged with Salmonella Heidelberg

“…Menconi et al (2014), evaluating two samples of lactic acid bacteria present in a commercial probiotic and incubated for two and four hours, respectively, at temperatures of 15ºC and 45ºC, detected growth under microaerophilic conditions. In the present study, the bacteria in the commercial probiotic product maintained at 25ºC grew under both aerobiosis and anaerobiosis up to six hours of incubation.…”

Antioxidant properties of Lactobacillus brevis of Horse Origin and Commercial Lactic Acid Bacterial Strains: A Comparison

“…All the isolated strains were able to tolerate pH (02-08) and presence of bile salt (0.5-2.0%) even for 24 hours of incubation at 37 o C. NaCl is an inhibitory substance which inhibit growth of many types of bacteria, therefore high salt tolerance is considered as a criteria of probiotic property. So, it was essential to test the NaCl tolerance of the isolates (Menconi et al, 2014). Hoque et al (2010) observed the NaCl (1-9%) tolerance of their Lactobacillus spp.…”

Metabolic diversity of bacteria and yeast from commercial probiotic products illustrated by phenotypic profiling

“…There is evidence that these two phenomena are related: the food sources and 482 molecular cues that microbes encounter in their environment affect their expression of proteins and 483 compounds (or community-level behavior such as aggregation and biofilm formation) that convey the 484 probiotic's beneficial effect. Further experiments are needed to measure a correlation between the 485 metabolic profiles and probiotic properties of these particular strains, similar to a study of two lactic acid 486 bacteria from the commercial culture FloraMax®-B11 [54]. Several examples of the relationship 487 between nutrient sources and bacterial probiotic phenotype include: increased resistance of L. plantarum 488 to gastric juices when growth with pectin or inulin compared to glucose [47]; differences in cell surface 489 hydrophobicity, cell surface protein and exopolysaccharide production of L. rhamnosus grown on 490 fructose, mannose, or rhamnose [55]; and increased the adhesion of Lactobacillus acidophilus to mucin 491 or intestinal cells in the presence of fructooligosaccharides (FOS), cellobiose, or polydextrose [56].…”