超长链多不饱和脂肪酸（VLCPUFAs）包括ARA、EPA、DHA等不但能营养机体，又具有独特生理功能而受到广泛的关注。破囊壶菌属微生物作为VLCPUFAs主要生产者，是鱼类、贝类等海洋生物富集积累VLCPUFAs的重要来源。许多研究指出，破囊壶菌具有大规模工业化生产VLCPUFAs的潜力。但是，目前对其的生物合成途径和组装机理仍未清楚。该综述从破囊壶菌属微生物的生物合成途径、储藏性脂质的组装机理和提高VLCPUFAs产量的基因工程策略三个方面进行介绍，着重对其VLCPUFAs的生物合成途径，及其油脂组装机理开展详细的介绍，并整理、结合一些较为前沿的研究发现对这些途径研究的潜在应用进行探讨，提高人们对破囊壶菌的生物合成及甘油酯组装途径的认知。研究表明，通过异源表达参与VLCPUFAs合成的基因，能在微生物工程菌和油料作物中产生EPA、DPA和DHA等功能油脂,含量能达到总脂的5%~40%，而通过基因工程敲除或改造破囊壶菌微生物的脂质合成途径基因，能提高破囊壶菌DHA产量约3%~55%。这些实例为指导VLCPUFAs的工业化生产，提供理论依据。

Very-long-chain polyunsaturated fatty acids (VLCPUFAs), including ARA, EPA, and DHA, are essential for human growth and well-being. They are produced mainly by the Thraustochytrids, a group of marine microorganisms that are the most important sources of these fatty acids for marine animals such as fish and shellfish. Although many studies have suggested the great potential of Thraustochytrids for the large-scale massive production of VLCPUFAs, the mechanisms of VLCPUFA biosynthesis in these microorganisms remain unclear. In this review, the VLCPUFA biosynthetic pathways of Thraustochytrids, the mechanisms of storage lipid assembly, and genetic engineering strategies for increasing VLCPUFA yields are introduced. Specifically, emphasis is placed on the aerobic and anaerobic biosynthetic pathways and the mechanisms of VLCPUFA assembly as well as the metabolic engineering applications of the pathway-related genes. This review presents a summary of findings from cutting-edge research studies to provide a better understanding of these biosynthetic pathways and their applications for VLCPUFA production. In conclusion, through the heterologous expression of genes involved in VLCPUFA biosynthesis, microorganisms and plants can accumulate functional lipids such as EPA, DPA, and DHA, which account for up to 5%~40% of the total lipids. However, through genetic engineering, the DHA yields of Thraustochytrids can be enhanced by approximately 3%~55%. These findings provide a theoretical basis and guidance for the industrial production of VLCPUFAs.

国家自然科学基金资助项目（42106130）；广东省高等教育厅青年创新人才项目（KA21031F5）；广东省基础与应用基础研究基金资助项目（B12100206）