Available online 20 September 2022

Ultrasonication was applied to stimulate the growth and Selenium biotransformation in Saccharomyces cerevisiae. Optimization study for maximal Se accumulation in S. cerevisiae was conducted using Plackett–Burman screening method and response surface methodology (RSM) for optimization of conditions. Screening of the variables influencing on Se biotransformation by yeast including duration and power of ultrasound, inoculum treatment with ultrasound, duty cycle, growth phase, time, shaking rate, inorganic salts concentration (Se, Zn, Mg, and K), nitrogen and carbon sources as well as their concentrations by using Plackett–Burman design.

Main variables were carbon and Se concentration, as well as ultrasound power and duty cycle. The lack of fit was insignificant (P > 0.01). The optimum condition for Se accumulation was obtained at Se concentration of 60 µg/ml, carbon source brix of 15, ultrasound of 90 W/L, and duty cycle 40%.

The results showed that optimization of parameters and application of ultrasonication lead to a successful enhancement (2.78-fold) in the accumulation of selenium by S. cerevisiae. Such enriched yeast can be utilized in bread for increasing consumption of Se in diet of patient with Se deficiency.

Agro-industrial waste

Biotransformation

Experimental design

Plackett–Burman screening method

Process variables

Response surface methodology

Saccharomyces cerevisiae

Selenium enrichment

Selenium

Selenium-enriched yeast

Ultrasound

© 2022 Published by Elsevier B.V. on behalf of Pontificia Universidad Católica de Valparaíso.