Growth promotion effect of red ginseng dietary fi ber to probiotics and transcriptome analysis of Lactiplantibacillus plantarum

Background: Red ginseng marc, the residue of red ginseng left after water extraction, is rich in dietaryfiber. Dietary fiber derived from fruits or vegetables can promote the proliferation of probiotics, and it is akey technology in the food industry to increase the productivity of probiotics by adding growthenhancingsubstances such as dietary fiber. In this study, the effect of red ginseng dietary fiber (RGDF)on the growth of probiotic bacterial strains was investigated at the phenotypic and genetic levels. Methods: We performed transcriptome profiling of Lactiplantibacillus plantarum IDCC3501 in two phasesof culture (logarithmic (L)-phase and stationary (S)-phase) in two culture conditions (with or withoutRGDF) using RNA-seq. Differentially expressed genes (DEGs) were identified and classified according toGene Ontology terms. Results: The growth of L.plantarum IDCC3501 was enhanced in medium supplemented with RGDF up to2%. As a result of DEG analysis, 29 genes were upregulated and 30 were downregulated in the RGDFtreatedgroup in the L-phase. In the S-phase, 57 genes were upregulated and 126 were downregulatedin the RGDF-treated group. Among the upregulated genes, 5 were upregulated only in the L-phase, 10were upregulated only in the S-phase, and 3 were upregulated in both the L- and S-phases. Conclusions: Transcriptome analysis could be a valuable tool for elucidating the molecular mechanismsby which RGDF promotes the proliferation of L.plantarum IDCC3501. This growth-promoting effect ofRGDF is important, since RGDF could be used as a prebiotic source without additional chemical orenzymatic processing. KCI Citation Count: 1