Accumulation of selenium and catalase activity changes in the cells ofSaccharomyces cerevisiae on pulsed electric field (PEF) treatment

The aim of this work is the evaluation of selenium accumulation and catalase activity in pulsed electric field (PEF) treatedSaccharomyces cerevisiae cells. Cultures ofS. cerevisiae in the medium containing selenium as sodium selenite were treated with PEF. Applied range of field parameters (field frequency of 1 Hz, intensity of 1.5 kV/cm and pulse duration of 1 ms) does not influence the changes of catalase activity which depend only on the concentration of selenium accumulated in the yeast cells. It was noted for the non-PEF-treated cultures that the accumulation of selenium in the yeast cells increased to 60 μg/g dry mass (DM) together with the increase of selenium concentration in medium from 1 to 3 μg/mL. Consequently, the activity of extra- and intra-cellular catalase also increased. At higher selenium concentrations in medium (4–6 ug/mL) its accumulation in the cells reached 127 μg/g DM which resulted in the decrease of catalase activity. In the PEF-treated cultures, twofold higher accumulation of selenium in the cells was obtained in the whole rang e of concentrations applied, which caused the significant decrease of catalase activity.