Effects of Selenium on Morphological Changes in Candida utilis ATCC 9950 Yeast Cells

Abstract

This paper presents the results of microscopic examinations of the yeast cells cultured in yeast extract–peptone–dextrose (YPD) media supplemented with sodium selenite(IV). The analysis of the morphological changes in yeast cells aimed to determine whether the selected selenium doses and culturing time may affect this element accumulation in yeast cell structures in a form of inorganic or organic compounds, as a result of detoxification processes. The range of characteristic morphological changes in yeasts cultivated in experimental media with sodium selenite(IV) was observed, including cell shrinkage and cytoplasm thickening of the changes within vacuole structure. The processes of vacuole disintegration were observed in aging yeast cells in culturing medium, which may indicate the presence of so-called ghost cells lacking intracellular organelles The changes occurring in the morphology of yeasts cultured in media supplemented with sodium selenite were typical for stationary phase of yeast growth. From detailed microscopic observations, larger surface area of the cell (6.03 μm2) and yeast vacuole (2.17 μm2) were noticed after 24-h culturing in the medium with selenium of 20 mg Se4+/L. The coefficient of shape of the yeast cells cultured in media enriched with sodium selenite as well as in the control YPD medium ranged from 1.02 to 1.22. Elongation of cultivation time (up to 48 and 72 h) in the media supplemented with sodium selenite caused a reduction in the surface area of the yeast cell and vacuole due to detoxification processes.

Effect of selenium on growth and antioxidative system of yeast cells

“…The result of such interactions are mutations and inactivation of various metabolic pathways. Moreover, selenium changes the morphological characteristics of yeast, e.g., changing the structure of the wall and membrane complex [2,33]. The reduction in membrane fluidity is associated with a higher content of saturated fatty acids, stronger hydrophobic interactions, and an increased content of phospholipids [34].…”

Accumulation of Selenium in Candida utilis Growing in Media of Increasing Concentration of this Element

“…The excess of selenium can be transported in yeast to the extracellular environment by means of membrane vesicles. They carry selenoprotein complexes across the cytoplasmic membrane [30][31][32]. Experiments carried out by Tarze et al [33] showed that detoxification of selenium in the presence of thiol compounds is associated with the release of H 2 Se into the cell exterior of yeast.…”

Inhibition of Candida albicans biofilm by pure selenium nanoparticles synthesized by pulsed laser ablation in liquids

“…Finally, Se NPs affect the morphology of C. albicans by shrinking and folding its outer cell membrane (Figure 6d). Indeed, as selenium and sulfur have similar chemical properties, excess selenium competes with sulfur in biological process by substituting it into amino acids which consequently affects the structure of proteins causing damage to the morphology of C. albicans (56). Other studies involving different nanoparticles having fungicidal activity against biofilm have been described (57–59), our group previously demonstrated that Ag NPs has the ability to inhibit C. albicans biofilm formation and filamentation due to cell wall disruption (23).…”