Choreography of multiple omics reveals the mechanism of lipid turnover in Schizochytrium sp. S31

Lipid turnover in Schizochytrium supports a preferential degradation of saturated fatty acids and a reservation of polyunsaturated fatty acids. In this study, multiple omics were utilized at different cultivation stages of Schizochytrium sp. S31 to reveal the mechanism of lipid turnover. During the lipid turnover stage, palmitic acid content decreased from 41.18% to 21.33%, while docosahexaenoic acid content increased from 31.20% to 50.43%. The lipidomic analysis showed that the lipid turnover mainly happened to saturated triacylglycerol accompanying with an increased level of phosphatidylinositol and phosphatidylcholine. The transcriptomic result further indicated that the differential expression genes related to the fatty acid degradation pathway were significantly increased, and the formation of phospholipids from diacylglycerol was enhanced. Finally, genomic sequencing and genetic engineering proved that the characterized triacylglycerol lipase might participate in the preferential hydrolysis of saturated fatty acids during lipid turnover. These results would not only enrich the current knowledge regarding the lipid turnover phenomenon but also contribute to the production of high quality single cell oil from microalgae.