Green macroalgae of the genus Ulva, commonly known as sea lettuces, are currently traded worldwide for multiple applications, including human consumption. In this work, we evaluated the seasonal variation of the total content of lipids, esterified fatty acids (FAs) and polar lipids (the major carriers of FAs) at the level of the classes and molecular species of Ulva rigida cultivated in Portugal in a land-based integrated multitrophic aquaculture (IMTA) system. Comparing winter, spring, summer and autumn samples, the lipid content and abundance of unsaturated FAs, namely n-3 polyunsaturated FAs, were highest in winter and lowest in summer. However, regardless of seasonal variations, U. rigida had a low n-6/n-3 ratio in all seasons, which is associated with health benefits. Among the polar lipids, those that varied the most were betaines, glycolipids and phospholipids, including a high number of lysolipid species that increased during autumn and spring. Multivariate analysis using principal component analysis (PCA) showed better discrimination of the four seasons when the dataset on molecular lipid species was used. Knowledge of the seasonal variability of lipid composition in biomass of Ulva rigida can be used to better explore these green macroalgae as a source of bioactive polar lipids with high market value.

Ulva属的绿色大型藻类（通常称为海生莴苣）目前在全球范围内交易有多种用途，包括人类消费。在这项工作中，我们评估了葡萄牙某土地上种植的Ulva harda种类和分子种类水平上脂质，酯化脂肪酸（FAs）和极性脂质（FAs的主要载体）总含量的季节性变化基础的综合多养水产养殖（IMTA）系统。比较冬季，春季，夏季和秋季的样品，不饱和脂肪酸（n -3多不饱和脂肪酸）的脂质含量和丰度在冬季最高，而在夏季最低。但是，无论季节如何变化，僵硬乌贼的n -6 /在所有季节中，n -3比率与健康益处有关。在极性脂质中，变化最大的是甜菜碱，糖脂和磷脂，其中包括在秋季和春季增加的大量溶脂类。使用分子脂质种类数据集时，使用主成分分析（PCA）进行的多变量分析显示了对四个季节的更好区分。了解乌贼硬质生物量中脂质组成的季节性变化的知识可用于更好地探索这些绿色大型藻类，作为具有高市场价值的生物活性极性脂质的来源。