Cellular modifications produced by D2O in yeast culture

The cellular cycle of the Saccharomyces Cerevisiae, chosen as experimental object, is unmodified by the presence in the culture medium of D2O at different concentrations. An increased concentration of D2O in the culture medium leads to a decrease of the number of budded cells, to metabolic alterations, to DNA structure modification as well as to enzymatic changes produced by blocking. Other anomalies appear, as a function of the cell defence capacity and of the influence of the factors from the nutrient substrate or exterior medium. Due to D2O, the medium's pH changes and modifications at the enzyme level and of the cell microstructure and morphology occur. The enzymatic reactions take place in D2O slower than in H2O. Three-dimensional modifications appear in the organic components of the live cell which, in turn, produce profound modifications in the cell growth and division. Due to the kinetic and isotopic effects, modifications of the biochemical reactions affecting the cell integrity happen