胁迫条件对酿酒酵母生物合成海藻糖的影响
毕业论文关键词：海藻糖；酿酒酵母；胁迫条件；发酵
Stress conditions on Saccharomyces cerevisiae biosynthesis of trehalose
Abstract：Trehalose is a non-reducing disaccharide, the structure is stable, in addition to being a carbon source storage, but also to protect the living body of proteins, nucleic acids and other macromolecules structure is not compromised external harsh environment, while the in vitro macromolecular there is a certain stability. But trehalose as a stress metabolite, only in nutritional deficiencies, growth retardation and other cases began to accumulate, yeast fermentation processes conventionally used, the trehalose yield is not very satisfactory, so this study by choosing shake bottle fermented potato dextrose solution as medium, the conditions on the basis of 28℃、200rpm, by changing the culture temperature, pH, osmolality, added toxic substances and metal ions and other methods to improve the accumulation of trehalose; and then have a comprehensive study of the above conditions. The results show: changes in temperature, pH, osmolality and Mg salt added, the accumulation of trehalose improved 1.20 times, 1.40 times, 1.14 times, 1.22 times; By orthogonal experiments, have the following scheme: temperature of 42.5 ℃, pH of 10.5, NaCl content of 0.35mol / L, Mg2+ content of 0.5mol / L. At this accumulation of trehalose increase by 1.27 times, compared to single stress effect is not the best, it is not the more severe conditions, the greater the accumulation of trehalose.
Key Words：trehalose；S.cerevisiae；stress；fermentation
目 录
1 绪论 1
1.1 本课题的国内外研究进展 1
1.2 本课题的研究内容、目的及意义 2
2 材料与方法 4
2.1 实验材料 4
2.1.1 菌株及培养基 4
2.1.2 实验试剂 4
2.1.3 实验设备 5
2.2 分析方法 5
2.2.1 菌液浓度测定方法 5
2.2.2 海藻糖含量测定方法 5
2.3 实验方法 7
2.3.1 酵母菌生长曲线及海藻糖含量变化的测定 7
2.3.2 胁迫条件下海藻糖含量的测定 7
3 结果与讨论 10
3.1 酵母菌生长曲线及海藻糖含量变化曲线测定 10
3.2 胁迫条件对酵母菌积累海藻糖的影响 10
3.2.1 温度对海藻糖积累的影响 10
3.2.2 pH对海藻糖积累的影响 11
3.2.3 乙醇对海藻糖积累的影响 12