Preliminary Evaluation of Probiotic Properties ofLactobacillusStrains Isolated from Sardinian Dairy Products

Abstract

Twenty-three Lactobacillus strains of dairy origin were evaluated for some functional properties relevant to their use as probiotics. A preliminary subtractive screening based on the abilities to inhibit the growth of microbial pathogens and hydrolyze conjugated bile salts was applied, and six strains were selected for further characterization including survival under gastrointestinal environmental conditions, adhesion to gut epithelial tissue, enzymatic activity, and some safety properties. All selected strains maintained elevated cell numbers under conditions simulating passage through the human gastrointestinal tract, well comparable to the values obtained for the probiotic strain Lactobacillus rhamnosus GG, and were able to adhere to Caco-2 cells to various extents (from 3 to 20%). All strains exhibited high aminopeptidase, and absent or very low proteolytic and strong β-galactosidase activities; none was found to be haemolytic or to produce biogenic amines and all were susceptible to tetracycline, chloramphenicol, erythromycin, ampicillin, and amoxicillin/clavulanic acid. Our results indicate that the Lactobacillus strains analyzed could be considered appropriate probiotic candidates, due to resistance to GIT simulated conditions, antimicrobial activity, adhesion to Caco-2 cell-line, and absence of undesirable properties. They could be used as adjunct cultures for contributing to the quality and health related functional properties of dairy products.

In Vitro Study on Release of Bioactive Antimicrobial Compounds From Dairy Products by Certain Promising Probiotic Lactobacillus Strains

“…During the study, R1 and R7 produced Bsh activity specific to bile salt (sodium cholate) hydrolysis. A similar result was also observed by Pisano et al (2014) [20] and Anas et al (2014) [21] where they found deposition of sodium cholate indicate a positive result for Bsh activity. L. casei MTCC 1423 (38.7%) and R1 (46.5%) showed maximum cell autoaggregation ability while cell surface hydrophobicity of strains R1 and L. casei MTCC 1423 have been reported as high 75.25 % and 65.853% respectively.…”

Evaluation of Probiotic L. rhamnosus GG as a Protective Culture in Sea Buckthorn-Based Beverage

“…The investigative probiotic, L. rhamnosus GG appeared to create an effective hurdle for multiplication of E. coli in the sea buckthorn-WPC system. Our work corroborates reports of other authors where they have suggested that fortification of Edam cheese with Lactobacillus rhamnosus LC705 significantly reduced E. coli counts [35,36]. Rolim et al demonstrated inhibitory effects of L. rhamnosus incorporated in semi hard goat cheese (coalho cheese) against pathogens like S. aureus, E. coli, L. monocytogenes, and S. enteritidis [37].…”

Lactobacillus plantarum LB95 impairs the virulence potential of Gram-positive and Gram-negative food-borne pathogens in HT-29 and Vero cell cultures

“…1a). Several studies showed that the percentage of LAB adhesion to gastric cells and Caco-2 cells is strain-dependent (Pisano et al, 2014;Delgado et al, 2015). However, Peres et al (2014) showed that the adhesion of Lactobacillus plantarum (LB95) and Lactobacillus paraplantarum (LB13) strains to Caco-2 cells was not significantly different from that of Lactobacillus casei Shirota, which is consistent with our results pertaining to HT-29 cells.…”