Isolation and Characterization of an Immune-Stimulating Lactic Acid Bacteria from Fermenting kimchi

Abstract

Isolation of Lactobacillus plantarum FBT215 (L. plantarum FBT215) from fermenting kimchi, which has immunostimulatory effects, was characterized in this study. To isolate probiotic lactic acid bacteria (LAB) from kimchi, properly diluted kimchi samples were spread on MRS agar incorporated BCP and sodium azide. One hundred fifty and four LAB isolates were isolated, screened for immune-stimulatory activities in murine RAW 264.7 cells. Among the 24 LAB strains after MTT assay, FBT215 has shown the best cytokine activity of expression of 676.9±22.2 pg/mL of interleukin IL-1α and 845.2±31.6 pg/mL of TNF-α. For identification, the typing experiments using 16S rDNA sequencing and API 50 CH kit confirmed that the FBT215 belongs to Lactobacillus plantarum, shortly called as L. plantarum FBT215. The FBT215 strain showed high antibiotic susceptibility, weak acid tolerance, bile salt tolerance and BSH activity but did not produce bacteriocin against indicator strains tested. API ZYM kit analysis resulted that the L. plantarum FBT215 produces seven different kinds of enzymes. In conclusion, these properties would be used as a functional probiotic culture in the manufacture of fermented foods.