Differences in phospholipid composition of autotrophic and heterotrophic Euglena gracilis

RESUMO

We have determined the phospholipid composition of E. gracillis under different environmental conditions. Half of the phosphoglycerides was phosphatidylcholine, regardless of growth conditions, but differences were noted in the distribution of the remaining lipids. Autotrophic, green, light-grown euglenas had 31% more amino-containing lipids (phosphatidylethanolamine and phosphatidylserine) than the heterotrophic, white, dark-grown cells. In contrast, dark-grow cells had 47% more anionic lipids, such as the ones belonging to the "phosphatidynositol cycle" (phosphatidylinositol, phosphatidylinositol-phosphate phosphatidylinositol-bis-phosphate and phosphatidic acid) plus cardiolipin. The results suggest an adaptation of some biosynthetic and degradative phospholipid pathways to autotrophic and to heterotophic growth