Fatty acid composition of the heterotrophic nanoflagellate Paraphysomonas sp.: influence of diet and de novo biosynthesis

摘要

We compared the relative importance of dietary factors versus de novo synthesis in determining the polyunsaturated fatty acid (PUFA) composition of the heterotrophic nanoflagellate Paraphysomonas sp. The flagellate was fed with different mutants of the picocyanobacterial strain Synechocystis PCC6803, which differ in their capability to synthesize specific PUFAs. The desA, desB, and desD genes of Synechocystis PCC6803 encode lipid desaturases at the A12, A15, and A6 positions of 18C fatty acids (FAs),respectively. Thus, the use of desA~-, desB~-, desD~-, and desA~/des D~- mutants of Synechocystis PCC6803 as food sources permitted us to provide the heterotrophic flagellate with decreasing levels of unsaturated FAs. In each treatment, Paraphysomonas s