[Effect of heavy water on the viability of bacteria]

Influence of heavy water (D2O) on the membrane energization, the efflux of hydrogen ions and the respiration of bacteria E. coli M-17 was studied. As has been shown, heavy water of a low concentration (0.05-0.20% v/v) activates and of a high concentration (above 10%) inhibits the absorption of lipophilic cation tetraphenylphosphonium (TPP+) and of oxygen by cells. The return of these characteristics to the initial levels after the removal of D2O points to a reversible action of D2O. A protective effect of D2O towards membrane energization and rate of respiration on dried cells was observed. This fact is in agreement with the data on viability of bacteria. The indicated protective action increases at the stage of rehydration in the presence of D2O.