Biotechnological properties of distillery and laboratory yeasts in response to industrial stresses.

The stress sensitivity of different wild-type strains was evaluated, as well as the response of cells arrested at different cell cycle positions to high hydrostatic pressure (HPP). HHP was chosen both for its importance in food decontamination and assessment of its suitability as a model for stress in general and understanding the yeast stress response. Studies were conducted with four industrial strains and four laboratory wild-type yeast strains (two haploid and two diploid) that differed in their backgrounds. Fundamental differences were found between the laboratory and industrial populations. Industrial strains were clearly more sensitive to hydrostatic pressure and ethanol stresses than the laboratory strains. However, ethanol production was higher in industrial strains than laboratory strains. Furthermore, no correlation was observed between ploidy and stress resistance. Yeast cells arrested in the G1 phase led to an enhancement in pressure tolerance compared to unarrested, G2 arrested, and S arrested cells. Moreover, cells arrested in the S phase were more sensitive to hydrostatic pressure than cells arrested in the G2 phase. Again, industrial strains were more sensitive than laboratory strains. HHP responses of industrial yeasts correlated well with both ethanol concentration and temperature stress, which suggests that it would be a useful model stress.