Abstract
This study characterized a lactic acid bacterium Leuconostoc mesenteroides HJ69 at biochemical and molecular level, isolate from traditional Korean fermented food Kimchi. Cell free supernatant (CFS) of L. mesenteroides HJ69 exhibited significant (P < 0.05) antibacterial effect as diameters of inhibition zones (14.34 +/- 0.31 - 18.21 +/- 0.23 mm) against the tested foodborne pathogenic bacteria with minimum inhibitory concentration and minimum bactericidal concentration values found in the range of 250-2,000 and 500-2,000 mu g/mL, respectively. Further, CFS of L. mesenteroides HJ69 revealed its mode of action on membrane integrity as confirmed by the increased release of potassium ions (800 and 750 mM/L), loss of 260-nm absorbing materials (3.85 and 3.77 OD), and increase in relative electrical conductivity (8.6 and 8.2%) against two selected bacteria L. monocytogenes KCTC-3569 (Gram-positive) and Escherichia coli O157: H7 (Gram-negative), respectively. The above findings hypothesize that L. mesenteroides HJ69 compromised its mode of action on membrane integrity, suggesting its enormous potential in the food industry.