장기간 발효 김치인 묵은지에서 분리한 Lactobacillus sakei JK-17의 기능성 조사

Abstract

The purpose of this work was to investigate the severalfunctional characteristics of Lactobacillus sakei JK-17isolated from long-term fermented kimchi, Muk Eun Ji. Initially,phylogenetic analysis using 16S rRNA sequencing wasperformed to identify the isolate JK-17, and the strain couldbe assigned to Lactobacillus sakei and designated as L. sakeiJK-17. The strain was registered in GenBank as [JX841311]. The changes of bacterial growth and residual organic acidswere monitored and HPLC was used to measure quantitativelytwo organic acids, lactic acid and acetic acid, producedin the culture during 84 hours of incubation. During the incubationperiod, several functional characteristics of L. sakeiJK-17 were examined. L. sakei JK-17 culture depleted nitriteconcentration 94.75%. Antioxidant activity of cultural supernatantsof L. sakei JK-17 was approx. 53.8%, and β-galactosidaseactivities were 0.243 units/mL at pH 7.0 and 0.387 units/mL at pH 4.1, respectively. The antibacterial activities againstfood-poisoning causing bacteria were examined with 20-foldconcentrated culture supernatants from L. sakei JK-17 and theantibacterial effects were clearly observed against all bacteriatested in this work.