Biochemical effects of certain amino acids such as aromatic andaliphatic side chain on Saccharomycesn cerevisiae L. causedoxidative damage by hydrogen peroxide

In this study, the effects of aliphatic and aromatic chained amino acids on antioxidant enzymes, lipophilic vitamins, fatty acid composition and malondialdehyde (MDA), glutathione (GSH) and oxidized glutathione (GSSG) levels of Saccharomyces cerevisiae, which added hydrogen peroxide (H2O2) to the cultural environment, were examined. Within the scope of the experiment, Control, H2O2, leucine, valine, phenylalanine and tryptophan and their H2O2 added groups were used. According to our findings, although total protein and MDA levels decreased in leucine and valine groups compared to the control group. It was determined that it increased in the groups to which H2O2 was added. GSH levels were also decreased in groups given H2O2. It was observed that the MDA and GSH results of the groups to which phenylalanine and tryptophan were added were similar to the leucine and valine groups. It was determined that the level of catalase enzyme increased in both the groups given phenylalanine and tryptophan and the groups given H2O2 compared to the control group. It was determined that palmitic acid level of fatty acids decreased in leucine and valine groups and H2O2 added groups compared to the control group. While the amounts of stearic, oleic and linoleic acid increased, only the amount of linoleic acid increased in the groups given H2O2. The palmitic acid result in the groups given phenylalanine and tryptophan and H2O2 was similar to the leucine and valine groups. An increase was observed in the amounts of stearic acid and linoleic acid in the groups given H2O2. Although the amount of α-tocopherol decreased in the leucine and valine groups compared to the control group, an increase was observed in the levels of ergosterol and stigmasterol. It was found that the change of ergosterol and stigmasterol in the groups given phenylalanine and tryptophan was similar. In addition, it was observed that the amount of α-tocopherol increased in the phenylalanine and tryptophan groups given H2O2 compared to the control group. As a result, it was observed that adding amino acids to the culture medium of S. cerevisiae was not effective in antioxidant defense against H2O2 toxicity and had a negative or positive effect on enzymes in lipid biosynthesis and other metabolic pathways.