摘要
Lactiplantibacillus plantarum L168 has been characterized as a novel probiotic and exhibited robust gastrointestinal tolerance,with survival of 65.61% at pH 3.0 and 75.27% resistance to intestinal fluid.Its cell-free supernatant exhibits potent antimicrobial activity against Staphylococcus aureus and Staphylococcus argenteus,producing inhibition zones exceeding 10 mm.Safety assessments confirmed no hemolysis,biogenic amine production,or mobile antibiotic resistance genes,alongside sensitivity to ampicillin and cephalosporins.Genomic analyses utilizing hybrid Illumina/Nanopore sequencing revealed a 3.37 Mb chromosome with 44.47%GC content,four plasmids,and 3502 genes,including 87 host-defense genes(CRISPR,stress-response)and 29 unique clusters associated with DNA repair,carbohydrate metabolism,and secondary metabolites.Comparative genomic analysis revealed over 99% average nucleotide identity with probiotic strains 299v,PS128,and WCFS1,yet L168 carried distinct bacteriocin clusters,containing four clusters with 22 genes,predicted to encode broadspectrum antimicrobial peptides,including PlnA/PlnEF precursors.Metabolomic profiling further identified bioactive metabolites such as Nicotinamide adenine dinucleotide(NAD)and indole-3-lactic acid(ILA),and exogenous tryptophan supplementation significantly enhanced ILA production.These findings highlight L168’s safety and genetic traits supporting gut microbiota modulation.Its genomic structure,resistance to acid and bile,and antimicrobial potential position make it a promising candidate for functional foods in treating intestinal inflammations and preventing pathogen infections.
基金
supported by the National Key Research and Development Program,2022YFA1303900
National Natural Science Foundation of China(NSFC)grant 82172288 to XL.
