Abstract:

In the production of glutathione (GSH) by Saccharomyces cerevisiae HSJB1 fermentation, effects of hydrogen peroxide (H2O2) concentration and its added time into fermentation medium on Saccharomyces cerevisiae HSJB1 biomass and GSH yield were investigated. The results showed that adding 0.01 g/L H2O2 at the beginning of fermentation and middle logarithmic growth phase and adding 0.1 g/L H2O2 at the stationary phase and highest-yield production phase of GSH had the promoting effect on the GSH production, but other situations had the reverse effect on it. The maximum GSH production yield was up to 43.73 mg/L, 5.3% higher than the control without H2O2 addition. Effects of addition of precursor amino acids, glutamic acid, cysteine and glycin at varying concentrations on Saccharomyces cerevisiae HSJB1 biomass and GSH yield were also investigated. The results showed that there were little changes in the Saccharomyces cerevisiae HSJB1 biomass and the GSH content with the concentration of glutamic acid increasing. With the concentration of glycin increasing, the Saccharomyces cerevisiae HSJB1 biomass decreased, but the GSH yield had no greatly change. Cysteine could markedly promote the production of GSH, and when the concentration of cysteine was 9 mmol/L, the GSH yield was 67.11 mg/L, 81.88% higher than the control without the addition.

Key words:  glutathione, Saccharomyces cerevisiae, oxygen stress, precursor amino acid