The aim of the study was to evaluate the functional properties of the Lactic acid bacterium Lactobacillus plantarumDGK-17 isolated from Kimchi-a traditional fermented Korean food, and to assess its antimicrobial and cell-invasion protection activity. Nutritionally improved DGK-17 showed antimicrobial activity, checked
via agar well diffusion assay against several pathogenic microorganisms and showed enhanced antimicrobial activity against target microbes Pseudomonas aeruginosa03K711 and Klebsiellapneumoniae05K279. Bactericidal activity of DGK-17 Cell-free Culture Supernatant (CFCS) was evident from the decreased growth of P. aeruginosa03K711 and K. pneumoniae05K279. Altered membrane integrity was observed in scanning electron microscopy which indicated that CFCS acts on cell membrane of bacteria leading to a cell burst. CFCS also acts on DNA as shown by the DNA damage study. Our auto-aggregation, co-aggregation and adhesion studies indicated that DGK-17 prevents colonization of pathogenic bacteria thereby limiting their infection. Also, DGK-17 is able to survive under low pH and high bile salt condition sea simulated gastric juice environment. Efficacy of DGK-17 to protect HCT 116 colon cells against P. aeruginosa (03K711) and K. pneumoniae(05K279) invasion suggests its role inprotection of host cells from such infections. Finally we conclude that L. plantarumDGK-17 has a strong
probiotic potential, antimicrobial activity and a potential for invasion protection