Abstract

Lactobacillus acidophilus KFCC12731 and Saccharomyces cerevisiae KFCC32017 were incubated together in soymilk and the conditions for acid production were investigated. The acid production of Lactobacillus acidophilus was much higher when this organism was incubated with Saccharomyces cerevisiae in soymilk than when it was incubated alone. Optimum acid production by the mixed cultures of Lactobacillus acidophilus and Saccharomyces cerevisiae was achieved with the following conditions; a temperature of 34$^{\circ}C$, a 3:7-8:2 (OD 660) ratio of Lactobacillus acidophilus to Saccharomyces cerevisiae at inoculum, a 1.5% level of sucrose fortification or a 2.0-3.0 % level of skim milk powder fortification and a culture time of 12 hours or more.

Lactobacillus acidophilus KFCC12731과 Saccharomyces cerevisiae KFCC32017을 두유 배지에 접종하여 산생성 조건을 검토하였다. L. acidophilus를 단독배양하는 것보다 S. cerevisiae와 혼합배양하는 것이 산생성이 많았다. 이 두 균을 대두유 배지에 혼합배양하였을 경우 최적조건은 다음과 같았다. 두유에 sucrose를 1,5% 또는 skim milk를 2.0~3.0% 첨가하고 L. acidophilus와 S. cerevisiae의 접종비율은 OD 600 값으로 3 : 7~8 : 2가 되게 접종하여 34$^{\circ}C$에서 12시간 이상 배양할 때 산생성이 최대가 되었다.

Keywords

• mixed culture;
• lactic acid fermentation;
• Soymilk