Fatty acid content in wild type and WZSL mutant of Euglena gracilis - Effects of carbon source and growth conditions

The effects of growth conditions on fatty acid profile were examined in the photosynthetic wild type and in the spontaneous non-photosynthetic WZSL mu tant of the unicellular flagellate Euglena gracilis. In the light, the amou nt of polyunsaturated fatty acids (PUFAs) is higher in the wild type than i n the mutant, independent of the carbon source. Among important PUFAs, lino lenic acid (18:3 omega3) is present in high amount only in wild type cells grown in the light with any of the tested carbon sources. The content of ot her PUFAs, such as arachidonic acid (20:4 omega6), EPA (20:5 omega3) and DH A (22:6 omega3), is not correlated with the presence of light or chloroplas ts. The main effect of the dark in both strains is to lower the content of PUFA s and mono-unsaturated fatty acids and to increase the content of saturated fatty acids with all the carbon sources.