Abstract:This study aims to isolate lactic acid bacteria with high-yield conjugated linoleic acid from Chinese paocai and baby feces, and then conduct functional and safety evaluations. 27 strains with CLA conversion rate greater than 8% were initially screened by ultraviolet spectrophotometry, identifying and classifying its CLA isomer composition by GC-Q-TOFMS. 8 lactic acid bacteria strains with more than 10% conversion rate of CLA and the mass concentrations of c9, t11-CLA, t10, c12-CLA isomers in the fermentation broth were higher than 20 μg/mL were obtained. The 8 strains were further evaluated characteristics such as self-aggregation, hydrophobicity, adhesion performance, gastrointestinal tolerance, antibacterial activity, and safety. The results showed that Lactobacillus plantarum NCU001044 and NCU006007 performed well overall, with self-agglutination rate of more than 60%, moderate hydrophobicity, and the adhesion rates were 8.81% and 9.10%, respectively. Their survival rates were 95.68% and 84.63% at pH 2.5 acidic conditions, and survival rates were higher than 65% in 0.3% bile salts. In terms of safety, the two strains are neutrally sensitive or sensitive to penicillin, benzamicin, tetracycline, and erythromycin and had no hemolytic activity. In this study, two Lactobacillus plantarum stains were screened with high biotransformation ability of beneficial CLA isomers and great probiotics potential. They have good ability to colonize the gastrointestinal tract, as well as acid and bile salt tolerance, besides show high inhibitory effect on pathogenic bacteria, which could be further used in the development of fermentation products and functional probiotics.