김치로부터 분리한 항균 활성을 가진 Leuconostoc mesenteroides TA의 특성 및 그 항균 물질의 특성 규명

Abstract

A lactic acid bacterium having antifungal activity was isolated from kimchi. The isolate was identified as Leuconostoc sp. based on its morphological and biochemical properties, and 16S rRNA gene sequences determination. Growth and antifungal, and antibacterial activities of Leu. mesenteroides TA were measured at 28℃, 30℃, and 37℃ at 24, 48 hr. The effects of initial pH (pH 4.0, 5.0, 6.0, 6.5, 7.0) on growth, antifungal and antibacterial were also determined. Leu. mesenteroides TA could grow well at 30℃ with initial pH of 6.0∼7.0. Leu. mesenteroides TA was non-hemolytic. To obtain antibiotic susceptibilities of LAB, minimum inhibitory concentration (MIC) of 9 antibiotics for Leu. menseteroides TA. Leu. menseteroides TA was sensitive of ampicillin, vancomycin, gentamycin, streptomycin, erythromycin, clindamycin, tetracycline, chloramphenicol. The enzyme profiling is an important factor for selection of strains as starter cultures. The enzymatic potential of the Leu. mesenteroides TA was evaluated using the API ZYM kit. Leu. mesenteroides TA was observed strong α-glucosidase activity and β-glucosidase. Leu. mesenteroides TA showed antifungal activity against Aspergillus fumigatus ATCC 96918, A. flavus ATCC 22546, A. ochraceus PF-2, A. nidulans PF-3, Penicillium expansum KCTC 6434, and Pichia kudriavzevii GY1 using a dual culture overlay assay and paper disc assay. Furthermore, Leu. mesenteroides TA represented antibacterial activity against various species of gram-positive and gram-negative bacteria. The antifungal and the antibacterial activity were stable at heat or proteolytic enzyme treatment, but it was unstable at pH 5.0∼7.0. The antifungal compounds were partial purified by solid phase extraction (C18 SPE column), and The antifungal compounds were observed antimicrobial activity. The antifungal compounds showed antifungal activity against various species of fungi. However, The antifungal compounds were not inhibited almost bacteria except Bacillus sp. The antifungal and the antibacterial compounds were stable at heat or solvent, but it was unstable at pH 3.0 and pH 5.0∼8.0