Yeasts enriched with microelements
1991
Szabo, G. | Barkoczai, L. | Janzso, B. | Suhajda, A. (Budafoki eleszto- es Szeszgyar (Hungary))
In laboratory experiments the growth of yeast in enriched medium in a 10 l fermentor was followed with an optical densitometer against the appropriately diluted sample of the non-inoculated culture fluid. The non-inoculated sample was measured with a spectrophotometer at 520 nm. The selenium concentration was determined in the fermented liquor subsequent to hydrolysis by the inductive connected plasma atom-emission method (ICP). The growth of Saccharomyces cerevisiae was only slightly retarded by added Na2SeO3 under 100 ppm concentration. The decrease of pH in the course of fermentation favourably influenced the rate of selenium up-take in the media of different composition, at the same time the selenium taken up by the yeasts accumulated in an inorganic form. The oxygen content dissolved in the medium played a similarly important role. The dissolved oxygen was very important for the chemical transformation of the Na2SeO3 within and outside the cell. An analysis of the selenium-containing yeast has shown a 2.5-times increase in the cysteine content, while the other amino acids increased 1.2-1.5-fold. The selenium-containing yeast is sold under the name EPASEL. It is used as a cholesterol-reducing and anti-coagulant agent. At present the development of yeasts enriched by iron, copper and zinc trace elements is under way.
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