Characterization and Antibacterial Activity of Lactobacillus casei HK-9 Isolated from Korean Rice Wine, Makgeolli

Abstract

Abstract:1) The purpose of this work was to examine the antibacterial activity derived from a lactic acid bacterium isolated from korean rice wine, called makgeolli. Various physiological and biochemical properties of this strain were characterized. Both the BIOLOG system and phylogenetic analysis using 16S rRNA sequencing were utilized for identification, and the strain was designated as Lactobacillus casei HK-9, and registered in GenBank as [JQ951606]. Growth rate, production of organic acids (e.g., lactic acid and acetic acid), and pH changes during growth were monitored. The maximum concentrations of lactic acid and acetic acid were approximately 576 mM and 199 mM, respectively, and pH was changed from 7.00 to 3.74 after 72 h of incubation. HPLC was used to confirm the production of lactic acid and acetic acid. Significant antimicrobial activity of the concentrated supernatant was demonstrated against various food-poison causing bacteria (e.g., Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, Escherichia coli, Salmonella enteritidis). Ethanol tolerance of L. casei HK-9 showed up to 12% of ethanol within the culture.

Characterization of Lactobacillus brevis JBE 30 as a Starter for the Brewing of Traditional Liquor

“…2). 이러 한 결과는 막걸리에서 분리했던 L. casei의 경우 6% 에탄올이 첨 가된 배지에서 정상적인 증식과 달리 10% 이상의 에탄올 함유 배지에서는 증식이 거의 정지되었다는 보고 (Baek et al, 2012) 와 유사하였다.…”

“…한편, JBE 30 균의 배양액을 pH 6.0으로 조절한 뒤 원심 분리하 여 얻은 상등액을 처리했을 때 유해균에 대해 항균력은 없거나 미미한 수준이었다. 이 결과들은 생산된 항균 물질이 중성 pH에 서 항균 활성을 가지지만 산성에서 활성을 잃든지 (Baek et al, 2012), 또는 유기산 생성으로 인한 pH 저하 때문 (Kim and Lee, 2013) …”

“…현재까지 전통주 양조에 적합한 유산균 균주는 에탄올 내성, 젖산 생성 능력, 항균 활성, 산 내성을 기준으로 하여 선발해 왔다 (Lee, 2000;Bae et al, 2007;Baek et al, 2012;Jang et al, 2013). 이 기준에 따라 선발된 유산균들은 대부분 산 생성능이 우수하여 배양액의 pH를 4.0 미만으로 감소시켰다.…”