Probiotic Properties Of Lactobacillus Strains Isolated From Chinese Sauerkraut And Chicken Intestines

In this study, Lactobacillus strains isolated from Chinese sauerkraut and chickenintestines were evaluated for probiotic potential with the resistance to acid and bilesalt, the ability to adhere to Caco-2cells, and adhesion associated cell surfaceproperties. The functional properties of in vitro antioxidant ability and cholesterolremoval activity were also investigated. The results were as follows.Acid and bile salts tolerant results showed that all strains isolated from Chinesesauerkraut and chicken intestines could survive in the medium at pH3.0and thesurvival rates were high than80%after incubation for3h. Strains S2-6, S5-6, S7-9,CH6-7, CH6-4, CH6-17, and CH17-1were able to survive at more than60%at pH2.0after3h incubation. All the strains survived well in the presence of oxgall at0.3,0.5or1.0%in MRS broth, and there was a trend of decreasing bacterial viability withincreased concentration of oxgall.All strains were tested for the surface properties and adhesion to Caco-2cells.Most strains of probiotics showed relatively higher hydrophobicity with chloroform.The greatest affinities with chloroform were observed in S2-6, S3-8, S5-2, and CH6-4.Unlike chloroform, the bacterial adhesion to xylene and ethyl acetate was low.Auto-aggregation was strain-specific, strains S2-1and CH6-7had highautoaggregation percentage after being incubated at room temperature for7h. Alltested strains showed some coaggregation properties with pathogens. But thisproperty was also strain-specific. Strain CH6-7showed the strongest coaggregationwith four pathogens. All of the selected strains showed various adhesion rates toCaco-2cells varied depending on the strain. Strains S5-9and CH6-4adhered better toCaco-2cells than other strains tested.The strains were investigated for the in vitro scavenging activity against hydroxyland2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals. The intact cells of all strainsshowed lower hydroxyl radicals scavenging activity. Strains S2-4, S6-4, S7-2, andCH7-1showed higher DPPH free radicals scavenging activities with an inhibition rateof77.22%,67.44%,54.71%and81.62%, respectively. In addition, strains S5-9, S6-4, CH6-4, CH6-14showed high cholesterol removal rate in the media containing100mg/L of cholesterol or0.3%(w/v) of oxgall, reaching78.14%and73.58%,76.49%and80.36%,respectively.