Lipidomic fingerprinting of the red seaweed Asparagopsis spp. evidencing specific profiling in gametophyte and tetrasporophyte life stages

In recent years, there has been a growing interest in seaweed biomass for multiple industrial applications due to their broad spectrum of high-value nutrients and bioactive metabolites. Seaweed lipids, and particularly the polar lipids, are a source of polyunsaturated fatty acids (PUFA), which have been reported to possess various biological activities, and are a sustainable alternative to fish oils. However, the profile of polar lipids in seaweeds is still understudied and therefore it is crucial to expand the knowledge of the lipidome of seaweeds, particularly of those with commercial potential, including the invasive species such as Asparagopsis sp. These invasive species produce a large biomass, making it a sustainable strategy for reducing its abundance, which would result in both environmental and economic benefits.This study aimed to comprehensively characterize the fatty acids and polar lipid profile of the two Asparagopsis species (A. armata and A. taxiformis), across two life stages (gametophyte and tetrasporophyte) and two different origins (wild and cultivated), using highly sensitive mass spectrometry-based approaches.Our study provides the first detailed characterization of the polar lipidome of Asparagopsis species and revealed that the gametophyte stage exhibited a greater number of polar lipid species than the tetrasporophyte stage. The phosphatidylcholine and the sulfoquinovosyl-diacylglycerol classes are the most abundant in all the samples studied. Although the lipidome of A. armata and A. taxiformis from the gametophyte stage showed similar distributions, variations in the relative abundance of lipid molecular species were observed. The statis-tical analysis of all A. armata specimens revealed that the lipid profile of samples from the same life stage were similar, regardless of their distinct origin (i.e., wild and cultivated). Furthermore, several polar lipid species with reported bioactivity were identified in Asparagopsis spp., providing insights into the lipid composition of these invasive species and their potential for further biotechnological applications. However, given the low absolute content of lipids in Asparagopsis species, it is unlikely to be viable to use nuisance or farmed biomass as a source of lipids alone.