The domesticated marine microalga Diacronema lutheri is of great interest for producing various highly valuable molecules like lipids, particularly long‐chain polyunsaturated fatty acids (LC‐PUFA). In this study, we investigated the impact of phosphorus (P) and nitrogen (N) starvation on growth, carbon fixation (photosynthetic activity) and partitioning, and membrane lipid remodeling in this alga during batch culture. Our results show that the photosynthetic machinery was similarly affected by P and N stress. Under N starvation, we observed a much lower photosynthetic rate and biomass productivity. The degradation and re‐use of cellular N‐containing compounds contributed to triacylglycerol (TAG) accumulation. On the other hand, P‐starved cells maintained pigment content and a carbon partitioning pattern more similar to the control, ensuring a high biomass. Betaine lipids constitute the major compounds of non‐plastidial membranes, which are rich in eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Under P and N starvations, EPA was transferred from the recycling of membrane polar lipids, most likely contributing to TAG accumulation.

中文翻译：

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海洋微藻Diacronema lutheri（Haptophyta）中磷和氮饥饿期间的碳分配和脂质重塑。

驯化的海洋微藻Diacronema lutheri对于产生各种高度有价值的分子（例如脂质），特别是长链多不饱和脂肪酸（LC-PUFA），具有极大的兴趣。在这项研究中，我们研究了分批培养过程中磷（P）和氮（N）饥饿对藻类生长，碳固定（光合作用）和分配以及膜脂质重塑的影响。我们的结果表明，光合作用机制同样受到P和N胁迫的影响。在氮饥饿下，我们观察到光合速率和生物量生产率要低得多。细胞中含氮化合物的降解和再利用促进了三酰甘油（TAG）的积累。另一方面，饥饿的细胞保持色素含量和碳分配模式与对照更加相似，从而确保了高生物量。甜菜碱脂质是非质膜的主要化合物，富含二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）酸。在P和N饥饿的情况下，EPA从膜极性脂质的循环利用中转移出来，最有可能促进TAG的积累。