Genomic insights of Lactiplantibacillus plantarum CNPC024: a potential probiotic strain producing immune-boosting tryptophan-derived metabolites.

Abstract

Probiogenomics can provide important insights bout probiotic candidate bacteria. This study aimed to perform an in-depth genomic characterization of the probiotic candidate Lactiplantibacillus plantarum CNPC024 to investigate its probiosis mechanisms, identify metabolic pathways that might benefit the host, and improve the safety assessment for this strain to be effectively used as a probiotic. After whole-genome sequencing in Illumina MiSeq platform, the de novo genome assembly resulted in a 3.2Mb draft genome. According to the Average Nucleotide Identity (ANI) analysis with 46 randomly validated probiotic LAB belonging to the Lactobacillaceae family, the strain showed a 99% nucleotide identity with other L. plantarum probiotic species. We identified a set of determinants conferring tolerance to bile salts and low pH conditions, as well as temperature, oxidative and osmotic stressors via the glutathione-glutaredoxin system (Grxs). As a β‑galactosidase‑producing strain, it has the potential to be used in fermented dairy products for lactose-intolerant individuals. There were no significant hits for transferable antibiotic-resistance genes. We also identified gene clusters associated with production of bacteriocins (plantaricins E, F and K). Lastly, we detected metabolic pathways associated with the production of tryptophan-derived metabolites that could potentially modulate the host's immune responses.