Molecular species composition of polar lipids from two microalgae Nitzschia palea and Scenedesmus costatus using HPLC-ESI-MS/MS

Abstract

This study examines the polar lipid profiles of two freshwater algae, Scenedesmus costatus and Nitzschia palea. HILIC-ESI-MS/MS analysis was used to determine and quantify the major phospholipids and glycolipids, as well as their relative molecular species, extracted from the two microalgal cultures. Glycolipids were eluted first, followed by phospholipids partially co-eluting with a sulfoglycolipid. The fragmentation pattern in the negative ionization mode for galactolipids was studied, revealing the stereospecific distribution of fatty acids on the glycerol backbone. Green algae frequently include 18:3 fatty acid in both phospholipids and galactolipids, while monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) were more saturated and contained shorter acyls. The diatom phospholipids contained mainly molecular species with saturated or monounsaturated fatty acids, while MGDG and DGDG exhibited a higher proportion of polyunsaturated fatty acids, such as the unique and abundant MGDG (20:5/20:2).

Mixed light photoperiod and biocide pollution affect lipid profiles of periphyton communities in freshwater ecosystems

“…The injection volume and temperature were set to 20 µL and 40°C, respectively. The chromatographic separation and mass spectrometry conditions, as well as the method performances, are described in Mazzella et al (2023aMazzella et al ( ), (2023b. Quantitation of phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylglycerol (PG) were respectively carried out with: PC (16:0/18:1), PE (16:0/18:1), PG (16:0/18:1).…”

“…Additionally, we attempted to reassign molecular species to different autotrophic groups based on information from the literature (Opute 1974, Dunstan et al 1993, Bergé et al 1995, Lang et al 2011, Coniglio et al 2021, Mazzella et al 2023a. For example, molecular species containing C14:0, C20:5 or C22:6 were preferentially related to diatoms.…”