[Correlation between the cellular content of mobile water and the viability of lyophilized yeast cells]

Spin-echo NMR studies showed that lyophilized yeast cells contain isolated mobile water (IMW), whose content varied from 0.25% (of the dry weight of cells) in the lyophilized exponential-phase yeast cells to 3.8% in the lyophilized lag-phase and stationary-phase yeast cells. The viability rate of yeast cells varied from 20% in the lyophilized preparation of exponential-phase cells to 86% in the lyophilized preparation of early-stationary-phase cells. In the lyophilized preparation of yeast cells grown in a chemostat mode at a constant specific rate, the content of IMW depended on the growth-limiting factor, being minimal in the case of growth limitation by carbon source. In the latter case, the viability rate of cells was also minimal. The data obtained show that there is a correlation between the IMW content and the viability rate of yeast cells in lyophilized preparations.