Targeted and untargeted lipidomic analysis of haptophyte cultures reveals novel and divergent nutrient-stress adaptations

Lipids comprise a significant, highly plastic proportion of the biomass in haptophytes, ubiquitous, globally and genetically diverse clade photosynthetic microalgae. Recent studies have investigated cellular lipidomes disparate, individual species haptophytes under nutrient-replete nutrient-limited conditions, but not how vary across larger evolutionary or its ecological functional groups. We cultured eight including five strains Emiliania huxleyi, for analysis via high performance liquid chromatography–high resolution accurate mass–mass spectrometry (HPLC–HRAM–MS), performed untargeted computational hierarchical cluster analyses on their lipidomes. identified similarities differences along both lines, potential biomarkers haptophyte sub-clades, 38 glycosphingolipids, seven betaine-like lipids, three phosphatidyl-S,S-dimethylpropanethiol (PDPT) sulfo-phospholipids. also provide first evidence glycolipid, glucuronosyldiacylglycerol, eukaryotic conducted more targeted study four nitrogen- phosphorus-limited conditions to investigate lipidomic responses nutrient stress. Under N- P-limitation, exhibited disparate responses. Uniquely, response N-limitation, E. huxleyi CCMP 374 heavily upregulated PDPT from 3.6 ± 0.9% 10.4 1.5% quantified polar lipids. These previously uncharacterized limitation reflect divergent strategies challenge popular phenotypic extrapolations between species.