Preservation of Dry Cells by Trehalose

许多能在极度脱水中存活下来的生物（例如酵母细胞、种子、真菌孢子和某些显微动物）含有大量的糖，特别是双糖蔗糖或海藻糖。先前的研究表明，如果在这些糖的存在下干燥，亚细胞组分，如不稳定的酶和膜，可以完整地保存下来。如果在没有糖的情况下干燥，这些分子组合就会完全不可逆地降解。这一现象已经被用来开发在没有水的情况下保存蛋白质、膜和脂质体的方法，并获得了几项专利，这些专利正在工业中使用。目前的项目将亚细胞部分的信息扩展到完整的细胞。傅里叶变换红外光谱用于研究完整酵母细胞中膜的状态，这些细胞以干燥的方式导致各种海藻糖的积累。这些研究旨在验证海藻糖稳定完整细胞细胞膜的方式与分离细胞膜的方式大致相同的假设。一个海藻糖依赖的相图将产生的细胞，不仅应该测试这一假设的细节，但也将立即实际应用于酵母工业影响提高脱水存活率。将寻求一种将海藻糖引入干燥状态下的细胞的方法，这种细胞通常不能在脱水中存活。选择的路线是使用酵母中发现的海藻糖的转运体。分子生物学技术将用于克隆这种转运体的基因。在这项研究中，合作者已经开发出了缺乏这种基因的突变体。目的是通过这些突变体的互补来获得基因。如果成功，该基因将在随后的研究中被引入其他细胞。

Many organisms that survive extreme dehydration (including, for example, yeast cells, seeds, fungal spores, and certain microscopic animals) contain large quantities of sugars, particularly the disaccharides sucrose or trehalose. Previous studies have shown that subcellular fractions such as labile enzymes and membranes can be preserved intact if they are dried in the presence of these sugars. If they are dried without the sugars these molecular assemblages are completely and irreversibly degraded. This phenomenon has been used to develop means for preserving proteins, membranes, and liposomes in the absence of water, leading to several patents that are in use in industry. The current project extends the information about subcellular fractions to intact cells. Fourier transform infrared spectroscopy is used to study the state of membranes in intact yeast cells that have been dried in ways that result in accumulation of various amounts of trehalose. These studies are designed to test the hypothesis that trehalose stabilizes membranes in intact cells in much the same ways as it does in isolated membranes. A trehalose-dependent phase diagram will be produced for the cells that should not only test this hypothesis in detail, but will also be of immediate practical use in the yeast industry in effecting increased survival of dehydration. A means will be sought to introduce trehalose into cells in the dry state that would not normally survive dehydration. The route chosen is to use a transporter for trehalose that is found in yeasts. Molecular biology techniques will be used to clone the gene for this transporter. Mutants have already been developed by collaborators in this research that lack this gene. The aim is to obtain the gene by complementation of these mutants. If successful, the gene will be introduced into other cells in subsequent research.