Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China; Beijing Chaoyang Foreign Language School, Beijing 100020, China; Institute for Food & Bioresource Engineering, College of Engineering, Peking University, Beijing 100871, China.
Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China; College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China.
Bioresour Technol. 2022 Mar;347:126401. doi: 10.1016/j.biortech.2021.126401. Epub 2021 Nov 23.
This study explored the regulation of photosystem and central carbon metabolism in cell growth and fucoxanthin accumulation of Isochrysis zhangjiangensis via transcriptome analysis, targeted metabolite measurements, and flux balance analysis. High light promoted biomass accumulation but dramatically decreased fucoxanthin productivity. It suppressed the active photosystem and reduced chlorophyll content, but improved metabolic flux of Calvin-Benson-Bassham and tricarboxylic acid cycle for massive biomass accumulation. The CO fixation was largely dependent on mitochondrial energy illustrated by the integrated metabolic tools. At a molecular level, glyceraldehyde-3-phosphate, acetyl-CoA, and pyruvate contents increased at exponential phase under high light, which tended to participate into fatty acid biosynthesis by the up-regulated ACCase. However, high light inhibited most genes involved in fucoxanthin biosynthesis and induced diadinoxanthin cycle to diatoxanthin form. Therefore, constant light at 100 μmol m s balancing biomass concentration and fucoxanthin content provided the highest fucoxanthin productivity at 3.06 mg L d.
本研究通过转录组分析、靶向代谢物测量和通量平衡分析，探讨了光合作用系统和中心碳代谢在中肋骨条藻细胞生长和岩藻黄素积累中的调控作用。强光促进生物量积累，但显著降低岩藻黄素生产力。它抑制了活跃的光合作用系统，降低了叶绿素含量，但提高了卡尔文-本森-巴斯汉姆循环和三羧酸循环的代谢通量，从而实现了大量的生物量积累。CO 固定在很大程度上依赖于线粒体能量，这一点通过综合代谢工具得到了说明。在分子水平上，高光下的指数生长期甘油醛-3-磷酸、乙酰辅酶 A 和丙酮酸含量增加，这可能通过上调的 ACCase 参与脂肪酸的生物合成。然而，高光抑制了大多数参与岩藻黄素生物合成的基因，并诱导了二氢二氧六环向二氧六环的形成。因此，在 100 μmol m s 的恒定光照下平衡生物量浓度和岩藻黄素含量，可使岩藻黄素生产力达到 3.06 mg L d 的最高水平。
