Abstract: o study the effect and mechanism of trivalent chromium on lipid metabolism in saccharomyces cerevisiae, total lipid, fatty acids, and triacylglycerol content in yeast were detected by oil red O staining and thin layer chromatography. The number of lipid droplets in yeast cells was observed by inverted fluorescence microscopy, and the fatty acid composition in yeast cells was analyzed by GC-MS. The effect of trivalent chromium on yeast lipid content was observed. Real time quantitative PCR further detected the transcription of genes related to yeast lipid metabolism and analyzed the mechanism of changes in yeast lipid content. Finally, the functional conservation was verified in SMMC-7721 cells. The results indicated that when treated with 100 μmol/L trivalent chromium, the contents of total lipids, fatty acids and triacylglycerol were reduced, the number of lipid droplets was decreased in cells, and the composition of fatty acids was regulated in yeast cells. The transcription of fatty acid uptake genesFAA1andFAA3and triacylglycerol synthesis genesDGA1andPAH1was significantly down-regulated by trivalent chromium in yeast cells. The lipid content and transcription of fatty acid uptake genesACSL1,ACSL3and triglyceride synthesis geneDGAT2was also reduced by trivalent chromium in SMMC-7721 cells. It is implied that trivalent chromium might control the lipid reduction by regulating the genes expressions involved in fatty acid uptake and triacylglycerol synthesis.

Key words: trivalent chromium;Saccharomyces cerevisiae, fatty acid, triacylglycerol, lipid droplet