Bioaccumulation of selenium and production of carotenoids by the yeast Rhodotorula mucilaginosa

Abstract

Rhodotorula yeast is capable of synthesising many valuable metabolites (carotenoids, enzymes). The biomass of these microorganisms is a valuable source of oils and numerous fatty acids. The ability to synthesise carotenoids and to bind various elements and permanently incorporate them into their cell structures makes them useful in many biotechnological fields. The article presents the results of research on the yeast Rhodotorula mucilaginosa MK1 (LC527461.1) grown in YPD liquid medium and selenium. The highest selenium content (1.19 mg Se4+/g) was bound by yeast grown in the medium with the addition of 20 mg Se4+/L after 96 h of cultivation. In the case of carotenoids, their highest content (346 μg/g) was found in the yeast biomass obtained from the control medium after 96 h of cultivation. The addition of 5 mg Se4+/L reduced the production of carotenoids to the level of 193.06 μg/g compared to the control sample. The highest protein content (64.9%) was recorded after 24 h of culture in the medium with the addition of 15 mg Se4+/L. Based on the obtained results, it can be observed that the yeast of the genus Rhodotorula mucilaginosa effectively binds selenium, and this property may find practical application in the production of selenium bioplexes. The presented research results are the basis for further analyses aimed at explaining the influence of selenium on the ongoing detoxification and metabolic processes in eukaryotic cells on the example of red yeast.