酿酒酵母抗冷冻干燥内在机理初步研究

Study on Inherent Mechanism of Lyophilization Resistance of Saccharomyces Cerevisiae

通过对酿酒酵母HS-2菌株在冷冻干燥处理前后细胞内海藻糖含量的变化和在不同悬浮基质中细胞存活率的差异等方面的研究，结果表明：酿酒酵母HS-2菌株在冷冻干燥过程中，每克细胞海藻糖含量明显增加，由1.58mg上升到9.34 mg。以NFS 10 % 脱脂复原乳为悬浮基质比以生理盐水为悬浮基质更有利于酿酒酵母HS-2菌株在冻干过程中细胞内海藻糖的积累，冻干后细胞内海藻糖含量高的菌株，细胞存活率高，其抗冷冻干燥的能力强。外源性海藻糖能提高酿酒酵母HS-2菌株在冻干过程中细胞的存活率，其中，以8%为较佳的添加浓度。海藻糖与蔗糖均可作为酿酒酵母HS-2菌株在冻干过程中的保护剂，但作用效果存在着差异，要使酿酒酵母HS-2菌株在冻干过程中达到基本相同的存活率，蔗糖的需要量要大于海藻糖。

Changes of the amount of intracellular trehalose before and after lyophilization on Saccharomyces cerevisiae HS-2 strain were studied. Diversity survival ratio of HS-2 strain in different suspension medium was compared in this experiment. The results showed as follows: The amount of intracellular trehalose in per gram cells of HS-2 strain went up obviously from 1.58 mg before lyophilization to 9.34 mg after lyophilization.The amount of intracellular trehalose of HS-2 strain in skim milk was higher than that in aseptic water. The cells survival ratio of HS-2 strain was high when the amount of intracellular trehalose after lyophilization was high .At this time , it was able to resist lyophilization. The trehalose added could promote survival ratio of HS-2 strain after lyophilization.It was better when the trehalose concentration was 8 %. Both trehalose and sucrose worked as cryoprotectant when HS-2 strain was lyophilized. Two kinds of sugarg differed in their optimum concentration. The amount of sucrose added was more than that of trehalose added when HS-2 strain reached approximately the same survival ratio after lyophilized.