在一定营养条件下，特别是饥饿、减数分裂和孢子形成阶段，产油微生物通过脂质反耗促使胞内的非极性油脂发生水解，为细胞代谢提供所需的能量和中间产物。裂殖壶菌脂质反耗导致其胞内饱和脂肪酸被优先水解，长链多不饱和脂肪酸得以迅速“浓缩”。阐明裂殖壶菌脂质反耗的分子机制，对改善裂殖壶菌DHA品质，提高DHA产率具有重要的意义。本项目拟利用脂质组学研究方法对裂殖壶菌脂质反耗过程中胞内脂肪酸的迁移规律进行系统研究，分析脂肪酶、TAG合成酶和甘油激酶等脂质反耗关键酶基因转录水平和酶活的变化规律，阐释裂殖壶菌脂质反耗的分子机制，为进一步完善裂殖壶菌脂质代谢调控机制，通过基因工程手段提高裂殖壶菌DHA产率，优化DHA品质，改善裂殖壶菌工业发酵生产DHA的环境友好性提供理论依据和新思路。

Under certain conditions, such as nutrient starvation, meiosis and sporation stages, lipid turnover typically commences in oleaginous microorganisms, which lead to hydrolysis of non-polar oils providing energy and intermediate metabolites for cell metabolism. During lipid turnover stage of Schizochytrium, the intracellular saturated fatty acids were preferentially hydrolyzed and the long-chain polyunsaturated fatty acids were concentrated rapidly. Therefore, it is very important to elucidate the molecular mechanisms of lipid turnover for improving the quality and increasing the yield of DHA of Schizochytrium. The primary aims of this project are to elucidate the molecular mechanisms of lipid turnover, improve and perfect the regulation mechanisms of lipid metabolism, enhance the yield and quality of DHA of Schizochytrium by means of genetic engineering methods, as well as improve the environmentally friendly processes of Schizochytrium fermentation. Accordingly, the migration of intracellular fatty acids during the lipid turnover stage of Schizochytrium will be explored using lipidomics methods. Moreover, the transcriptions of the key enzyme genes and the activities of enzymes, including lipases, glycerol kinase and TAG synthase etc., will be analyzed.