School of Life Sciences, Ludong University, Yantai 264025, China.
School of Resources and Environmental Engineering, Ludong University, Yantai 264025, China.
Biomolecules. 2024 Jul 9;14(7):822. doi: 10.3390/biom14070822.
The diatom , known for its high triacylglycerol (TAG) content and significant levels of n-3 long chain polyunsaturated fatty acids (LC-PUFAs), such as eicosapentaenoic acid (EPA), has a limited ability to utilize exogenous organic matter. This study investigates the enhancement of acetate utilization in by introducing an exogenous acetate transport protein. The acetate transporter gene from endowed the organism with the capability to assimilate acetate and accelerating its growth. The transformants exhibited superior growth rates at an optimal NaAc concentration of 0.01 M, with a 1.7- to 2.0-fold increase compared to the wild-type. The analysis of pigments and photosynthetic activities demonstrated a decline in photosynthetic efficiency and maximum electron transport rate. This decline is speculated to result from the over-reduction of the electron transport components between photosystems due to acetate utilization. Furthermore, the study assessed the impact of acetate on the crude lipid content and fatty acid composition, revealing an increase in the crude lipid content and alterations in fatty acid profiles, particularly an increase in C16:1n-7 at the expense of EPA and a decrease in the unsaturation index. The findings provide insights into guiding the biomass and biologically active products production of through metabolic engineering.
硅藻以其高甘油三酯（TAG）含量和高水平的 n-3 长链多不饱和脂肪酸（LC-PUFAs），如二十碳五烯酸（EPA）而闻名，其利用外源有机物的能力有限。本研究通过引入外源乙酸盐转运蛋白来提高 的乙酸盐利用能力。来自 的乙酸盐转运蛋白基因 赋予了生物体同化乙酸盐的能力，并加速了其生长。在最佳 NaAc 浓度为 0.01 M 时，转化体表现出更高的生长速率，与野生型相比增加了 1.7-2.0 倍。对色素和光合作用活性的分析表明，光合作用效率和最大电子传递率下降。这种下降被推测是由于乙酸盐利用导致光系统之间的电子传递成分过度还原。此外，该研究评估了乙酸盐对粗脂质含量和脂肪酸组成的影响，发现粗脂质含量增加，脂肪酸谱发生变化，特别是 EPA 减少，C16:1n-7 增加，不饱和指数降低。这些发现为通过代谢工程指导 的生物量和生物活性产物生产提供了思路。
