Accumulation and metabolism of selenium by yeast cells

Abstract

This paper examines the process of selenium bioaccumulation and selenium metabolism in yeast cells. Yeast cells can bind elements in ionic from the environment and permanently integrate them into their cellular structure. Up to now, Saccharomyces cerevisiae, Candida utilis, and Yarrowia lipolytica yeasts have been used primarily in biotechnological studies to evaluate binding of minerals. Yeast cells are able to bind selenium in the form of both organic and inorganic compounds. The process of bioaccumulation of selenium by microorganisms occurs through two mechanisms: extracellular binding by ligands of membrane assembly and intracellular accumulation associated with the transport of ions across the cytoplasmic membrane into the cell interior. During intracellular metabolism of selenium, oxidation, reduction, methylation, and selenoprotein synthesis processes are involved, as exemplified by detoxification processes that allow yeasts to survive under culture conditions involving the elevated selenium concentrations which were observed. Selenium yeasts represent probably the best absorbed form of this element. In turn, in terms of wide application, the inclusion of yeast with accumulated selenium may aid in lessening selenium deficiency in a diet.

Effect of selenium-enriched defatted rape seeds on tissue cadmium and essential elements utilization in rats

“…However, the unregulated intake of dietary or pharmacological Se supplements, mainly in inorganic form, has potential to expose the body tissues to toxic levels of Se with subsequent negative consequences for DNA integrity (Brozmanova et al 2010). There are various approaches for dietary Se supplementation, where the addition of selenized yeast is frequently considered as the efficient one, because yeast species such as Saccharomyces cerevisiae, Candida utilis, and Yarrowia lipolytica are able to accumulate substantial amount of Se in their cells (Rayman 2004;Kieliszek and Blazejak 2013;Kieliszek et al 2015).…”

ATP synthesis in the energy metabolism pathway: a new perspective for manipulating CdSe quantum dots biosynthesized in <em>Saccharomyces cerevisiae</em>

“…The content level was higher than that of WT cells during the testing period, which may be because the addition of CdCl 2 in seleniumized cells stimulated an increase of GSH. 37 And because the addition of Na 2 SeO 3 would trigger the upregulation of GSH, 27 with lower intracellular Se concentration, the GSH cannot be used effectively 38 and results in the higher GSH content in Δatp1 cells at time 0 than that of WT cells. These results ( Figure 3A and B) attested that within the low ATP synthesis strains (such as Δatp1) mentioned, it was the utilization rather than synthesis of GSH that was impeded by the ATP levels.…”

“…As it was reported, S-adenosylmethionine (SAM), one of the intermediate species of the methionine and cysteine metabolism pathway, needs methionine as a substrate and ATP for synthesis under the action of acyltransferase. 48 Its seleno analog, SeAM, the synthesis of which is also affected by ATP content, 38 is believed to be an important intermediate compound in the biosynthesis of CdSe QDs in yeast (unpublished data). An increase in ATP could lead to the accumulation of SAM, and under Se-rich culture, it would be SeAM.…”

Selenium‐enriched Saccharomyces cerevisiae improves growth, antioxidant status and selenoprotein gene expression in Arbor Acres broilers

“…Saccharomyces cerevisiae is not only the most useful yeast, with a crucial role in winemaking, baking and brewing since ancient times, but it also serves as an ideal carrier for converting inorganic Se to organic Se because of its high Se absorption rate (Kieliszek et al., ). Currently, it is an important by‐product, as yeast slurry accounts for 0.15% of beer production (dry substance), and it could be used as an alternative feed additive because of its high protein content.…”