Isolation of antifungal activity of Leuconostoc mesenteroides TA from kimchi and characterization of its antifungal compounds

Abstract

Strain TA harboring antifungal activity was isolated from kimchi and identified based on Gram-staining, biochemical properties using an API 50 CHL, determination of rRNA gene sequences, and RAPD analysis. The determined gene sequences and RAPD pattern showed 100% homology with those of Leuconostoc mesenteroides ATCC 8293T. However, their properties were slightly different from each other. Especially, TA could not utilize lactose while strain ATCC 8293 could use lactose. Leu. mesenteroides ATCC 8293 showed higher antibacterial activity against Bacillus cereus than Leu. mesenteroides TA, whereas the antifungal activities of these 2 LAB against Aspergillus fumigatus were the same. Leu. mesenteroides TA showed broad antimicrobial activities against Gram-positive and - negative bacteria as well as molds. We determined that the responsible antifungal compounds from Leu. mesenteroides TA are lactic acid, acetic acid and unidentified hydrophobic compound(s). Additionally, synergistic interactions involving acetic acid, lactic acid, phenyllactic acid, and unidentified hydrophobic compound(s) contribute to the overall inhibitory activity of Leu. mesenteroides TA.