Optimization Of Se-yeast Growth Conditions And Research Of Antioxidant Activity

In order to provide theoretical foundation for research on yeast as engineering strain applied to functional Se-enriched fermented food, this paper studied the effect of sodium selenite on the growth and antioxidant activity of saccharomyces cerevisiae JS. The main results were as follows:1. Sodium selenite with lower concentration could accelerate the growth of the two yeast strains(strain F: salt tolerance yeast; strain JS: saccharomyces cerevisiae). In detail, 0.5μg/m L of sodium selenite and addition at 12 h has the most obvious acceleration effect on the growth of strains. At this condition, the ADH activity and alkaline protease were promoted significantly(p<0.05). Moreover, organic selenium transfer rate is in excess of 80%, within the limits of security.2. In the growth of saccharomyces cerevisiae JS, the consumption of Asp, Thr, Ser, Glu, Cys, Met, Lue and Arg is relatively bigger than others; Ile, Tyr and Trp were released not consumed. Met, Cys, Ser, Arg and Asp obviously promoted the growth of saccharomyces cerevisiae JS through developing it in the amino acids culture medium.3. The effects of sodium selenite, Met, Cys, Ser, Arg and Asp were studied separately. And the results reflect 0.5μg/m L sodium selenite has a most acceleration effect on the GSH-PX activity but not on the radical scavenging activity; Hydroxyl radical scavenging activity was enhanced distinctly by Asp, while superoxide radical scavenging activity was enhanced by Cys, Met and Arg.4. For the sake of studying the associated influence of Se and amino acids on the antioxidant activity, sodium, Ser, Met and Cys were added at the same time. Three ANNs were established with high correlation(R2=0.95, 0.97, 0.93) for predicting the effect of sodium selenite, Ser, Met and Cys on the antioxidant activity.The above are the main conclusions of this paper, from which, we could reasonably certain that a low dose of sodium selenite could accelerate the growth, biological and antioxidant activity, and better effect with amino acids. BP ANNs could predict the antioxidant activity commendably. Strain JS could applied to functional Se-enriched fermented food with better antioxidant activity.