Euglena gracilis as source of the antioxidant vitamin E.: Effects of culture conditions in the wild strain and in the natural mutant WZSL

The photosynthetic wild type and the spontaneous non-photosynthetic WZSL mutant of the unicellular flagellate Euglena gracilis were grown to investigate the influence of photoheterotrophic and heterotrophic conditions on alpha-tocopherol (vitamin E) content. HPLC analysis demonstrated a marked enhancement (almost 100%) of tocopherol content in the light in both strains, independent of the presence of chloroplasts. These findings indicate that the formation of vitamin E occurs inside both the mitochondrial and chloroplastic compartment, and that the correlation between light and vitamin E production is not linked to the existence of chlorophyll.