Optimization of Selenium Yeild by <i>Saccharomyces sp</i>. III Using Statistical Designs

The objective of the study was to optimize the conditions in a culture medium for the selenium yeild enriched by Saccharomyces sp. III using Plackett-Burman design and Box-Behnken design. The Plackett-Burman multifactorial design was first employed to screen the significant factors in the fermentation for the selenium yeild, and subsequent use of the response surface methodology was further optimized for the selenium yeild by Box-Behnken design. The important factors in the culture medium, identified by the initial screening method of Placket-Burman, were sodium selenite, glucose and the liquid volume. The optimal amounts for maximum selenium yeild were: sodium selenite 15.8 mg/L; glucose 40.2 g/L; the liquid volume 120 mL in 250 mL flask. Using this statistical experimental design, the selenium yeild under optimal condition reached about 1679.32 μg selenium /g dry cell.