清酒酵母の生理 (第4報) : 清酒釀造過程に於ける酵母醗酵能並びにそのアルコール耐性の消長

概要

論文の詳細を見る
Moto in the secondary stage and also the yeast isolated from it showed the highest fermentability, but the yeast cell lacked alcohol tolerance. In the resting stage of Moto, changes in the components of Moto as well as in the fermentability of the yeast became gradually milder, until at last they seemed to establish an equilibrium state, while the yeast cells continued to be increased in the nitrogen content and became resistant to 15 volume % alcohol. We consider that the valuable effect of the ripening process of Moto, which often continues as long as a month, may be probably attributed to kill or weaken the acidifying bacteria by the accumulated acid, since the reproductivity of the yeast has been scarcely affected by the length of ripening period. It is interesting that the yeast in the resting Moto, in spite of 20 days incubation, does not diminish its fermentability, even under such a condition as there is accumulated over 10 % alcohol. This fact might be due to the rich nitrogen content of the yeast cells grown under the circumstances supplying abundant nitrogenous matters.In the beginning of the Moromi-process the yeast cells showed the highest value of the fermentability and nitrogen content, but lacked alcohol tolerance.The yeast in this stage does not encounter so high concentration of the sugar as in the beginning stage of the Moto-process, because the consumption of sugar by growing yeast and the accumulation of it by the amylolytic action of Koji occur simultaneously and compensate each other.When the fermentation of Moromi was proceeding to the highest the number of yeast cells largely increased while their nitrogen content as well as the fermentability were reduced at first, and then gradually re-increased. The cells in this stage are somewhat resistant to alcohol. When the fermentability was estimated in the presence of 15 % alcohol, that is, the cells were steeped in it for a few hours during estimation, they showed alcohol tolerance, although they were strongly damaged by steeping for such a long period as 20 hours at 28℃.However, after the fermentation had reached to its highest degree, the yeasts acquired more and more alcohol tolerance with respect to the fermentability, even in the case of steeping in 15 % alcohol for 20 hours at 28℃, so that the yeast showed the second maximum value of fermentability in this stage of the Moromi-process, in which alcohol had been accumulated to about 15 % or more.Near the ripening stage of Moromi, the fermentation gradually weakened, but alcohol still increased to 18 % or more, and the nitrogen content and alcohol tolerance of the yeasts were again reduced.
社団法人日本生物工学会の論文
1951-11-15

清酒酵母の生理 (第4報) : 清酒釀造過程に於ける酵母醗酵能並びにそのアルコール耐性の消長

スポンサーリンク

概要

著者

関連論文

スポンサーリンク