The metabolic response of yeast as a model organism to Epicoccum nigrum pigments' antioxidant activity

Abstract

Two Epicoccum nigrum parental and mutant strains were used as good producers of carotenoid and flavonoid intracellular complex of pigments biosynthesized in solid state cultivation system. In the previous researches a high antioxidant activity of the fungal pigments was found. The aim of the work was to investigate the antioxidant action of carotenoids and flavonoids complex extracted from the Epicoccum nigrum mycelia upon the cells of the Saccharomyces cerevisiae strain as a model organism. Yeast was cultivated in submerged system on Malt Extract medium enriched with different concentrations of Epicoccum nigrum mycelial extract containing carotenoids and flavonoids in variable ratios. Yeast growth was monitored by measuring optical density and by direct counting with Thoma cytometer. Cell multiplication was monitored at different moments using kinetic parameters, like number of generations, rate of multiplication and generation time. Cell viability and stability in time were estimated through microscopic observation of cell suspended in methylene blue, used as redox indicator. Results showed that Epicoccum nigrum pigments increased the cell multiplication and metabolic activity and decreased the intracellular oxidation with positive effects on cell stability and viability.