Studies on the differentiation and the population changes of Takju yeasts by the TTC-agar overlay technique

TTC-agar중층법에 의한 탁주효모의 유별 및 그 소장에 관한 연구

1. The yeasts in the two samples of Nuruk (mold wheat) which one prepared at the College of Agriculture, Choong-Nam University (S) and the other purchased at a market(T), were examined and counted. The yeasts were differe entiated by the market (T), were examined and counted. The yeasts were differe entiated by the TTC(2,3,5-triphenyltetrazolium chloride)agar overlay technique that yields a varied shade of color. The results were : the population of yeasts in 1g of Nuruk S was about $6{\times}10^4$, 56.5% of which were TTC-pink yeasts, 16% TTC-red pink yeasts, 8% were TTC-red yeasts, and 16.5% TTC-white yeasts. In Nuruk T(1g), the number of yeasts accounted for $14{\times}10^4$ and constituted of 42% TTC0pink, 21% TTC-red pink, 23% TTC-red and 9% TTC-white. 2. During the fermentation of Takju (Korean Sake) employing the Nuruk S and T the yeast flora throughout the brewing were observed in 12 hour intervals. TTC pink and red yeasts considered to be the major yeasts were isolated all cultured. The strains ($1{\times}10^5$/ml) were added to the mashes S and T in which pH was adjusted to 4.2 and the change of yeast flora was examined during fermentation.