Abstract
Euglena gracilis Z, a wild strain and a bleached mutant SM-ZK contained considerable amounts of polyunsaturated fatty acids.
E. gracilis grown under photoautotrophic conditions were rich in linolenic acid and contained rela-tively small amounts of C20 polyenoic acids. On the other hand, E. gracilic grown under heterotrophic conditions contained a large amount of polyenoic acids, including arachidonic acid. These polyenoic acids were contained in the polar lipid fraction ; oleic acid was rich in the pellicle complex, linolenic acid in chloroplasts and arachidonic acid and eicosapentanoic acid in the mitochondria and microsomal fractions. The lipid types synthesized by Euglena in the light and in the dark, and their oxygen dependency were studied.
The major polyunsaturated fatty acid in photoauxotrophic cells was linolenic acid. Illumination induced only linolenic acid formation, and arachidonic and eicosapentanoic acids were synthesized in-dependent of light effect. Anaerobic conditions induced the formation of saturated fatty acids and themajor saturated fatty acids was myristic acid.
