Simultaneous Optimization of the Production of Organic Selenium and Cell Biomass in Saccharomyces Cerevisiae by Plackett-Burman and Box-Behnken Design

Selenium (Se) as a vital trace element has many biological activities such as anti-inflammation and anti-oxidation. Selenomethionine as an organic selenium plays a vital role in the response to oxidative stress. At present, Saccharomyces cerevisiae is one of the best microorganisms that has the ability to accumulate selenium. Production of Seleno-yeast was done by growing Saccharomyces cerevisiae in the presence of water soluble selenium salt (Na(2)SeO(3)) as a part of the medium. The yield of selenium biotransformation and yeast biomass can be improved by optimizing the process conditions in two steps. First, the effects of several culture parameters (culture conditions and culture media) were studied using the Plackett-Burman design. After that, determining the optimum levels of the effective parameters was performed by Box-Behnken response surface methodology. Optimization of the conditions was performed with the aim of simultaneously optimizing the biomass and selenium biotransformation. In this investigation, the effect of the eleven culture parameters was studied with Plackett-Burman design. Then, four significant culture parameters such as glucose concentration, aeration, selenium concentration, and temperature were optimized with Box-Behnken response surface methodology.