SACCHARIDES THAT PROTECT YEAST AGAINST HYDROSTATIC-PRESSURE STRESS CORRELATED TO THE MEAN NUMBER OF EQUATORIAL OH GROUPS

Several saccharides were found to be significantly effective in provid ing protection against hydrostatic pressure and high temperature damag e in the yeast Saccharomyces cerevisiae. The extent of barotolerance a nd thermotolerance with seven different sugars showed a linear relatio nship to their mean number of equatorial OH groups. The same linear re latioship is seen when sugars protect protein molecules against elevat ed temperatures iii vitro. Some sugars were more effective in providin g protection against hydrostatic pressure nearly a hundred times than high temperature. Pre-heat shock treatment on yeast cells induce vario us stress tolerances. In this report, pre-heat shocked cells showed po tent protection against elevated temperature, but these cells showed f aint protection against elevated pressure. These results suggest that sugars may protect cells against hydrostatic pressure and high tempera ture in a similar manner, probably by stabilizing the macromolecule(s) , and such type of protection may be suited for pressure stress.