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Enhancement of Alcohol Tolerance of Yeast Applying Pressure Stress of Cell and Pressure Reversal of Anesthesia

细胞压力和麻醉压力逆转增强酵母的酒精耐受性

基本信息

批准号：
04808045
负责人：
TAMURA Katsuhiro
金额：
$ 1.02万
依托单位：
The University of Tokushima
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

项目摘要

In the presence of relatively low concentrations of ethanol, small aquatic animals such as tadpoles sink to the bottom of a water tank, but they begin to swim when a pressure of about 20 Mpa is applied. This phenomenon of recovery from an anesthetized state on application of pressure is known as pressure reversal of anesthesia and is the reason why pressure is often used to investigate the mechanisms of action of anesthetics. This phenomenon has also been observed with some microorganisms. On application of pressure to suspensions of E.coli containing a few per cent of ethanol, survival of the cells increases with increase in pressure up to 10-20 Mpa.Yeast produces ethanol from glucose and this product should act an anesthetic on the cells. Accordingly, the growth of yeast should gradually be retarded and some cells should die with the progress of fermentation. If pressure is applied to this system, survival of yeast should be greater than at atmospheric pressure. Therefore, as an application of this phenomenon, we examined the pressure reversal for survival of yeast and examined the fermentation of glucose by yeast at high pressure.Pressure revesal of anesthsia was applied to alcoholic fermentation of glucose by yeast. The survival of yeast in the absence of ethanol decreased with increase in pressure. However, in medium containing 4 and 8%(w/w)ethanol, cell survivals reached peaks at 20 MPa(200 bar). Although viable yeast cells apparently increased at a pressure of 20 MPa, no increase of the alcohol concentration was observed under the experimental conditions used.

在相对低浓度的乙醇存在下，小水生动物如蝌蚪会沉到水箱底部，但当施加约20 Mpa的压力时，它们开始游泳。这种在施加压力时从麻醉状态恢复的现象被称为麻醉的压力逆转，并且是压力经常用于研究麻醉剂作用机制的原因。这种现象也在一些微生物中观察到。对含有百分之几乙醇的大肠杆菌悬浮液施加压力时，细胞的存活率随着压力的增加而增加，最高可达10-20 Mpa。酵母从葡萄糖中产生乙醇，该产品应对细胞起麻醉作用。因此，随着发酵的进行，酵母的生长会逐渐减慢，一些细胞会死亡。如果对该系统施加压力，则酵母的存活率应大于大气压下的存活率。因此，作为这一现象的应用，我们研究了酵母存活的压力逆转，并研究了高压下酵母发酵葡萄糖的情况。在没有乙醇的情况下，酵母的存活率随着压力的增加而降低。然而，在含有4%和8%（w/w）乙醇的培养基中，细胞存活率在20 MPa（200 bar）下达到峰值。虽然在20 MPa的压力下活酵母细胞明显增加，但在所用的实验条件下没有观察到醇浓度的增加。