Department of Bioengineering, School of Minerals Processing and Bioengineering, Central South University, 932 South Lushan Road, Changsha, 410083, Hunan, P.R. China.
Key Laboratory of Biometallurgy, Ministry of Education, Changsha, Hunan, China.
World J Microbiol Biotechnol. 2024 Aug 12;40(10):298. doi: 10.1007/s11274-024-04082-z.
Mortierella alpina is popular for lipid production, but the low carbon conversion rate and lipid yield are major obstacles for its economic performance. Here, external addition of organic acids involved in tricarboxylic acid cycle was used to tune carbon flux and improve lipid production. Citrate was determined to be the best organic acid that can be used for enhancing lipid production. By the addition of citrate, the lipid titer and content were approximately 1.24 and 1.34 times higher, respectively. Meanwhile, citrate supplement also promoted the accumulation of succinate, an important value-added platform chemical. Owing to the improved lipid and succinate production through adding citrate, the carbon conversion rate of M. alpina reached up to 52.17%, much higher than that of the control group (14.11%). The addition of citrate could redistribute carbon flux by regulating the expression level of genes related to tricarboxylic acid cycle metabolism. More carbon fluxes flow to lipid and succinate synthesis, which greatly improved the carbon conversion efficiency of M. alpina. This study provides an effective and straightforward strategy with potential economic benefits to improve carbon conversion efficiency in M. alpina.
枝顶孢属真菌（Mortierella alpina）因其产脂能力而广受欢迎，但较低的碳转化率和产脂率是其经济性能的主要障碍。在这里，我们采用参与三羧酸循环的有机酸的外部添加来调节碳通量并提高脂质产量。确定柠檬酸是可用于提高脂质产量的最佳有机酸。通过添加柠檬酸，脂质的产率和含量分别提高了约 1.24 倍和 1.34 倍。同时，柠檬酸的补充也促进了琥珀酸的积累，琥珀酸是一种重要的高附加值平台化学品。由于添加柠檬酸可提高脂质和琥珀酸的产量，枝顶孢属真菌的碳转化率高达 52.17%，远高于对照组（14.11%）。柠檬酸的添加可以通过调节与三羧酸循环代谢相关的基因表达水平来重新分配碳通量。更多的碳通量流向脂质和琥珀酸的合成，这极大地提高了枝顶孢属真菌的碳转化效率。这项研究为提高枝顶孢属真菌的碳转化效率提供了一种有效且直接的策略，具有潜在的经济效益。
