College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, Zhejiang 315211, China.
The First Affiliated Hospital of Ningbo University, Ningbo, Zhejiang 315211, China.
Bioresour Technol. 2023 Dec;390:129912. doi: 10.1016/j.biortech.2023.129912. Epub 2023 Oct 23.
This research studied the metabolic mechanism of the mixotrophic Chaetoceros sp. The results showed this alga had the highest cell density and growth rate of 47.72 × 10 cells mL and 0.41 d, respectively, with a maximum dry weight of 2.90 g/L, when compared to photoautotrophic and photoheterotrophic modes. Compared to photoheterotrophy, transcriptomics results showed the Rubisco, PGK, and GAPDH related genes were separately up-regulated by 1.03, 2.36, and 1.36 times in CBB cycle in mixotrophic mode, suggesting intermediate metabolites of EMP and PPP can enter the chloroplast via transporter proteins, or membrane permeation, and feedback inhibition regulates the reduction of multiple reactions in CBB cycle. Chaetoceros sp. achieves high biomass by utilizing ATP and carbon structures from EMP and PPP pathways, and the addition of NaHCO leads to an up-regulation of CBB cycle for the mixotrophic alga, resulting in higher biomass compared to the photoheterotrophic mode.
本研究探讨了混养角毛藻的代谢机制。结果表明，与自养和异养模式相比，该藻类的细胞密度和生长率最高，分别为 47.72×10^6 个/mL 和 0.41 d，最大干重为 2.90 g/L。与异养相比，转录组学结果表明，在混养模式的 CBB 循环中，Rubisco、PGK 和 GAPDH 相关基因分别上调了 1.03、2.36 和 1.36 倍，这表明 EMP 和 PPP 的中间代谢物可以通过转运蛋白或膜渗透进入叶绿体，反馈抑制调节 CBB 循环中多个反应的还原。角毛藻通过利用 EMP 和 PPP 途径中的 ATP 和碳结构来实现高生物量，添加 NaHCO3 会导致混养藻类的 CBB 循环上调，从而产生比异养模式更高的生物量。
