分析了搭载于实践八号育种卫星的啤酒酵母的存活情况和糖代谢相关酶类活性。啤酒酵母于YPD液体培养基培养,培养过夜后用新鲜YPD稀释106倍,分装后分别置于地面和卫星搭载两种条件下15d。返回地面后收集样品,利用稀释平板计数法检测啤酒酵母活力,采用酶解结合分光光度法检澳4酵母糖原水平,分光光度法检测己糖激酶、琥珀酸脱氢酶和苹果酸脱氢酶的活性。结果发现,卫星搭载样品的菌落形成数显著高于地面对照组,卫星搭载样品是地面对照的3.1倍;卫星搭载啤酒酵母样品的己糖激酶和琥珀酸脱氢酶活性均明显低于地面对照组,而卫星搭载样品的苹果酸脱氢酶活性明显高于地面对照组;卫星搭载样品的糖原水平均低于相对应的地面对照组。表明,太空飞行下可导致啤酒酵母的存活率提高,同时伴有糖代谢相关酶活性和糖原水平的变化,提示太空飞行条件下引起糖代谢变化有利于啤酒酵母存活。
The viable conditions and activities of carbohydrate metabolism related enzymes (CMRE) of Saecharomyces cerevisiae took a flight in Practice 8 recoverable satellite for 15 days ( space yeast) were analyzed. The yeast was cultured in liquid YPD medium overnight, then diluted with fresh YPD to 10-6 times before taking the satellite flight and filled another one to keep on the ground for 15 days as a control. Alter recovery, the cell viability was determines by colony counting on flat plate, and the activities of CMRE including hexokinase, sucelnate dehydrogenase, malate dehydrogeuasc, and the content of glycogen in whole cells of both yeasts (satellite and ground) were tested and determined with zymolysis combined with spectrophotometry. The results showed that the colony forming amount of space yeast samples was obviousiy higher than that of the ground control samples, as high as 3.1 times, However, the activities of hexokinase and suecinate dehydrogenase of space yeast were obviously lower than the ground control one; but the activity of malate dehydrogenase of space yeast was higher than the ground control one. The content of glycogen of space yeast was lower than the ground control one. These indicated that under the space flight eould increase the viability ol the )east, and at the same time it accompanied with the changes of the activities of related enzymes and the level of glycagen that conduced to the viability of the yeast in space flight conditions.