Abstract: In this study, the functional genomic characteristics of Lactiplantibilus plantarum ST were analyzed. Comparative genomic analysis was performed on the whole genome sequences of L. plantarum ST and the type strain L. plantarum ATCC 14197T as well as those of 152 L. plantarum strains published in the NCBI GenBank. A phylogenetic tree was constructed based on 1 262 core genes of these 154 L. plantarum strains, and the genetic distance between ST and the intestinal isolate BCC9546 was found to be the closest. The isolates originated from milk and meat products were concentrated in the upper part and the lower part of the second branch, respectively, and they were different due to different sources and could be aggregated. Meanwhile, Drosophila isolates showed a significant aggregation trend. Functional annotation analysis suggested that the ST genome contained genes related to the phosphotransferase system (PTS) as a major carbohydrate transport system. Genes related to the immune regulatory pathway were also annotated. There were many genes related to the hydrolysis or rearrangement of glycosidic bonds, but no virulence factors or antibiotics resistance genes found in ST. Compared with the other L. plantarum isolates, ST carried the unique functional gene ecfT related to energy transport function. In addition, ST had functional genes involved in the synthesis of the quorum-sensing signaling molecule AI-2, glutathione, and adhesion molecules. The results of API 50 CHL carbohydrate metabolism showed that L. plantarum ST could utilize a wide range of carbon sources and metabolize 29 carbon sources including monosaccharides, glycosides, disaccharides and polysaccharides. This study provides a genetic basis for the development and utilization of L. plantarum ST as a safe probiotic strain.

Key words: Lactiplantibacillus plantarum ST; comparative genomics; functional genes