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.