Interaction of Lactobacillus helveticus YM-1 and Streptococcus lactis ${ML}_3$ on the Sugar Fermentation in Skim Milk

당발효에 미치는 Lactobacillus helveticus YM-1 과 Streptococcus lactis ${ML}_3$의 상호작용

The acid production and sugar utilization of Lactobacillus helveticus YM-1 between Streptecoccus lactic ${ML}_3$ were investigated in skim milk, cultured broth filtrate and semi-synthetic medium. The effect of acid production by mixed culture and in cultured broth filtrate of the other party were more than that of single culture and self-cultured broth filtrate. When the two strains were cultured 12 hrs, Streptococcus lactis ${ML}_3$ utilized with 0.4% lactose, Lactobacillus helveticus YM-1 with 0.85%, and mixed strains with 1.05% respectively. In 8 hrs fermentation Lactobacillus helveticus YM-1 and mixed strains accumulated 0.22%, 0.10% glucose in the medium respectively, and then decreased gradually. The glucose released by Lactobacillus helveticus YM-1 was stimulated the acid production of Streptococcus lactis ${ML}_3$.

L.helveticus YM-1 과 Str.lactis ${ML}_3$를 탈지유, 배양여액및 함성배지에 단독및 혼합배양 하였을때 산생성량과 당이용성 그리고 상관관계를 검토하였다. 자기자신의 배양여액보다 상대편의 배양여액에서, 단독배양보다 혼합배양의 경우가 산생성 촉진효과가 컸었다. 유당의 이용성은 12시간 배양했을때 Str. lactis ${ML}_3$ 의 경우 0.4%, L.helveticus YM-1은 0.85%. 혼합배양시는 1.05%였다. L.helveticus YM -1의 단독배양과 두균의 혼합배양의 경우 8시간후 배지에 생성된 포도당은 0.22%와 0.10%를 나타낸 다음 점차 감소하였다. L.helveticus YM-1에 의해서 생성된 포도당은 Str.lactis ${ML}_3$의 산생성을 촉진한다고 생각된다.