Analysis of the Probiotic Properties and Safety Assessment of Lactobacillus paracasei Based on Whole-Genome Sequencing
Description
This study conducted a comprehensive genomic and phenotypic evaluation of L. paracasei 150-1, a strain isolated from Tibetan dairy products. Whole-genome sequencing results revealed that the strain possesses a rich gene repertoire associated with carbohydrate utilization, amino acid metabolism, membrane transport, genetic information processing, and environmental adaptation, indicating its potential for metabolic diversity and adaptability. Genomic analysis related to safety indicated that, although several homologous genes associated with antibiotic resistance and host interaction were annotated, no acquired antibiotic resistance genes were detected, nor were typical toxin-associated virulence factors identified, suggesting a relatively low genomic safety risk. In vitro safety assessments further corroborated these findings. L. paracasei 150-1 exhibited no hemolytic, DNase, thrombin/thrombin inhibitor, gelatinase, urease, or indole-producing activity, and its lactate metabolism was dominated by L-lactate rather than D-lactate. Antibiotic susceptibility testing indicated that the strain was generally susceptible to the antibiotics tested, with no widespread phenotypic resistance observed. Furthermore, the strain exhibited good compatibility with Caco-2 cells, maintaining a cell survival rate of over 90% at all tested concentrations, and demonstrated moderate adhesion to intestinal epithelial cells, suggesting its potential for transient intestinal colonization and host interaction. In summary, L. paracasei 150-1 exhibits favorable biosafety characteristics and possesses the traits required for probiotic applications. Further research can be conducted to confirm its functional efficacy and application potential in the food industry.