耐冷冻酵母菌的筛选

Screening the Freeze-tolerant Yeast Strains

为从自然界中筛选出耐冷冻酵母菌 ,从土壤、谷物、果蔬、空气等不同来源筛选分离得到 6 0多株酵母菌 ,通过模拟面团预发酵进行耐冷冻酵母菌的初筛选 ,并通过普通面团预发酵进一步筛选 ,得到了 3株耐冷冻酵母菌 ,编号为 FTY2 8,FTY 31和 FTY 5 6。这 3株耐冷冻酵母菌冷冻 7d后存活率和相对发酵力均超过80 ,且海藻糖质量分数大大高于耐冷冻性较差的酵母菌 ,其质量分数最高达 16 .2。

In order to screen the freeze tolerant yeast strains, more than 60 yeast strains were isolated from various natural resources like soil, cereals, fruits & vegetables, air etc. The preliminary screening was done through prefermentating in simulative dough. Furthermore, the freeze tolerant yeast strains were screened through prefermentating in dough, FTY28, FTY31 and FTY56 were confirmed with the freeze resistant ability. Their survival rates and relative fermentative ability were more than 80 % after frozen for 7 days. Trehalose content of the frozen yeasts is much higher than that of the normal yeasts, the highest is up to 16 2 % .