Production of organically bound selenium yeast by continuous fermentation

Ali Demirci, Anthony L. Pometto

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31 Scopus citations

Abstract

This paper describes a protocol for incorporation of sodium selenite or sodium selenate into Saccharomyces cerevisiae biomass by continuous fermentation in a medium with minimal sulfur and methionine concentrations. Selenium incorporation was followed by atomic absorption analysis and methylene blue reduction time (MBRT). Continuous fermentation at 0.2 h-1 dilution rate and sodium selenite addition gradient up to 0.69 g/L of Na2SeO3 yielded 1.89 g/L of biomass with 1904 μg of selenium/g of dry biomass. However, MBRT was 0.1 min, which indicated that the majority of selenium was in the inorganic form. On the other hand, continuous fermentation at 0.2 h-1 dilution rate and sodium selenate gradient up to 0.28 g/L of Na2SeO4 yielded 0.76 g/L of dry biomass with 687 μg of selenium/g of dry biomass, and MBRT was 26 min, which indicated a high concentration of organically bound selenium. Overall, the results indicate a Se/S ratio of 3.9:1 and a dry biomass/Se ratio of 5.5:1 as optimal for continuous production of organically bound selenium.

Original languageEnglish (US)
Pages (from-to)2491-2495
Number of pages5
JournalJournal of agricultural and food chemistry
Volume47
Issue number6
DOIs
Publication statusPublished - Jun 1 1999

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All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Agricultural and Biological Sciences(all)

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