The impact of pre-radiation exposure on physiological and fermentation activity of Saccharomyces cerevisiae SAF Ale S-33.

Abstract

Purpose: The aim of this study was to evaluate the effect of radiation pre-exposure on the survival, physiological, and fermentation activity of Saccharomyces cerevisiae.

Materials and methods: The low-dose (20-80 cGy) irradiation was conducted using the medical therapy installation Xstrahl 320, which has a maximum energy of 320 keV and a dose rate of 1 Gy/min. High-dose (1 and 5 kGy) exposure was achieved by an electron beam using the linear accelerator UELR-10-10S with a maximum energy of 10 MeV and a dose rate of 1 kGy/s.

Results: The results showed that hyper-radiosensitivity of the yeast exposed to low-dose radiation occurred at 20 cGy and induced radio-resistance occurred at doses from 40 to 60 cGy, increasing survival. The pre-exposure of S. cerevisiae to 60 cGy radiation conferred adaptation on the yeast to withstand repeated exposure to a higher dose (1 kGy). The irradiation of S. cerevisiae with low doses ranging from 20 to 80 cGy decreased its physiological and metabolic activity compared to the non-irradiated yeast samples. The viability of the yeast was totally lost after exposure to 5 kGy, resulting in the death of all the yeast.

Conclusions: The pre-exposure of S. cerevisiae to radiation resulted in a decline in growth, vitality, metabolic activity, and fermentation activity. However, pre-exposure of the yeast to low-dose radiation (40 and 60 cGy) induced an adaptive response, reducing the damaging effect usually experienced from high-dose (kGy) exposure.