Insights of species-specific polar lipidome signatures of seaweeds fostering their valorization in the blue bioeconomy

Abstract

The valorization of seaweeds has generated unprecedented interest in recent years due to their unique chemical characteristics. The taxonomic differentiation between Chlorophyta, Rhodophyta, and Ochrophyta is often supported by their contrasting chemical characteristics. Polar lipids are the most abundant class of lipids in several seaweeds species often labelled as valuable phytochemicals. Nevertheless, little is still known about how the polar lipidome of seaweeds varies within and among different phyla. In this study, the polar lipidome of six seaweeds farmed under controlled conditions in a land-based integrated multitrophic aquaculture (IMTA), belonging to Chlorophyta (Ulva rigida and Codium tomentosum), Rhodophyta (Gracilaria gracilis, Palmaria palmata and Porphyra dioica), and Ochrophyta (Fucus vesiculosus) was characterized using state of the art high-resolution LC-MS analysis. The seaweeds were harvested during the same season and the same time window to control the biotic and abiotic shaping of their polar lipidome. In total, 477 different species of polar lipids (m/z values) were identified and distributed over the six seaweeds surveyed. Only a small group of 35 species of polar lipids were shared among all the seaweed species analyzed in this study. The distribution of the polar lipid species and lipid classes showed a trend towards grouping by phylum although seaweed specie specific polar lipid signatures can be assigned. Matching the data gathered in the present study with those previously acquired showed a species-specific clustering, which confirm the uniqueness of these natural biochemical fingerprints. Recognition of the specific lipidome is necessary because polar lipids are assigned with important bioactive properties. This knowledge will allow designing new strategies for chemical tuning during farming so that the yield of target compounds can be improved, and these valuable living resources can fully contribute to the sustainable growth of a blue bioeconomy.