Screening of lactic acid bacteria isolated from fermented Cornus officinalis fruits for probiotic potential

Abstract The objective of this study was to screen probiotic lactic acid bacteria (LAB) with beneficial properties such as acid and bile salt tolerance, antibacterial activity, autoaggregation ability, and cholesterol‐lowering capacity from fermented Cornus officinalis fruits. Eleven probiotic LAB strains, identified as ten Lactobacillus plantarum and one Lactobacillus casei, were screened out and evaluated by in vitro tests. The results of principal component analysis (PCA) based on probiotic characteristics suggested that L. plantarum 2519, 3725, and 3735 were promising probiotic candidates, which were better than the probiotic reference strain, Lactobacillus rhamnosus GG. Among them, L. plantarum 2519 showed the hightest autoaggregation value of 94.62%, and L. plantarum 3725 showed a cholesterol assimilation percentage of 47.83% and remarkable antimicrobial activity against five foodborne pathogens with the cell number decrease from 3.68 to 4.60 log cfu/mL. These results indicate that these three LAB strains are good candidates as probiotic starters. Practical applications Cornus officinalis is known as a kind of medicinal plant with fruits having many pharmacological activities, such as improving liver and kidney function, potent hpyerglycemic and antioxidant effect. C. officinalis is rich in endophytes, and its pharmacological activities may be associated with the metabolic products of endophytic bacteria. Therefore, the exploitation of microbial resources in spontaneous fermented C. officinalis fruits is beneficial to select probiotics. Moreover, the fruits from a natural reserve should be an excellent resource, attributing to the low impact of antimicrobial contamination may guarantee non or low intensity of antibiotic activity of their endophytic bacteria.