Overexpression of Malonyl-CoA: ACP Transacylase in Schizochytrium sp. to Improve Polyunsaturated Fatty Acid Production

作者：Zhipeng Li, Tong Meng, Xueping Ling, Jun Li, Chuqiang Zheng, Yanyan Shi, Zhen Chen, Zhiyang Li, Qingbiao Li, Yinghua Lu, Ning He · 发表于：Journal of Agricultural and Food Chemistry · 年份：2018 · DOI：10.1021/acs.jafc.8b01026 · 被引用次数：170 · 研究领域：Microbial Metabolic Engineering and Bioproduction、Enzyme Catalysis and Immobilization、Lipid metabolism and biosynthesis

Polyunsaturated fatty acids (PUFAs) have been widely applied in the food and medical industry. In this study, malonyl-CoA: ACP transacylase (MAT) was overexpressed through homologous recombination to improve PUFA production in Schizochytrium. The results showed that the lipid and PUFA concentration were increased by 10.1 and 24.5% with MAT overexpression, respectively. Metabolomics analysis revealed that the intracellular tricarboxylic acid cycle was weakened and glucose absorption was accelerated in the engineered strain. In the mevalonate pathway, intracellular carotene content was decreased, and the carbon flux was then redirected toward PUFA synthesis. Furthermore, a glucose fed-batch fermentation was finally performed with the engineered Schizochytrium. The total lipid yield was further increased to 110.5 g/L, 39.6% higher than the wild strain. Docosahexaenoic acid and eicosapentaenoic acid yield were enhanced to 47.39 g/L and 1.65 g/L with an increase of 81.5 and 172.5%, respectively. This study provided an effective metabolic engineering strategy for industrial PUFA production.