[Observation of the processes of low-temperature crystallization in an aqueous cell suspension by electron microscopy]. / Nabliudenie protsessov nizkotemperaturnoi kristallizatsii v vodnoi suspenzii kletok metodom élektronnoi mikroskopii.

The possibility of using electron microscopy for the study of the processes of the low-temperature crystallization of water in cell suspension is discussed with E. coli M-17 culture used as an example. The replacement of water in the frozen state permits the observation of processes occurring in the sample at low temperature. The advantages of the method are demonstrated in the study of objects previously frozen at different rates.

[Effect of heavy water on the viability of bacteria]. / Vliianie tiazheloi vody na protsessy zhiznedeiatel'nosti bakterii.

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.

[Effect of a modification of the medium on the structure of bacterial cells based on electron microscopy data]. / Izuchenie vliianiia modifikatsii sredy na strukturu bakterial'nykh kletok po dannym élektronnoi mikroskopii.

Electron microscopy was used to study the interactions between microorganisms and the culture medium in the presence of modifying agents. Temperature-dependent changes in the intensity of water-glycerin exchange between the cells and the medium are demonstrated, which is of interest for the optimization of the conditions of using protectors, as well as for the study of the permeability of cell membranes.

[The effect of dehydration dynamics on the characteristics of the E. coli cells]. / Vliianie dinamiki obezvozhivaniia na kharakteristiki bakterial'nykh kletok E. coli.

It was shown that NMR and IR-spectroscopy may be employed to study the dynamics of cell dehydration on E. coli as an example. It was noted that the withdrawal of the cell binding water causes an increase of the relative protein quantity in beta-turn. Similar dependences on the relative humidity have been obtained both for chemical shift and the changes of the secondary protein structure and the number of viable cells. It was concluded that the processes associated with binding water removal should be considered as one of the main factors, causing the inactivation of the bacterial cells.

[Study of low temperature crystallization in E. coli cells using NMR]. / Izuchenie nizkotemperaturnoi kristallizatsii v kletkakh E. coli metodom IaMR.

Freezing and thawing processes of the E. coli cell suspension have been studied by NMR. It was shown that the degree of the cell dehydration correlated with its freezing time. The effect of the recrystallization processes was evaluated and its temperature range was indicated. It was noted that nonfreezing water content increased during thawing of the cells as compared to this content at the same temperature during freezing.

[Water exchange in E. coli cells in the presence of D20 using IR-spectroscopy]. / Issledovanie vodnogo obmena v kletkakh E. coli v prisutstvii D20 metodom IK-spektroskopii.

Time dependence of isotopic composition of intracellular water was studied by the method of infrared spectroscopy after D2O adding into outer medium of E. coli, M-17. These changes were shown to be periodic with the time of repeating of extremums near two min. Such oscillations are connected with periodic processes which take place in the cell itself under the influence of D2O and characterized a degree of viability of organisms.