The lipid composition of algae is crucial for numerous structural and physiological aspects, e.g. the integrity of the photosynthetic
complexes and the functionality of membrane-embedded processes as the photosynthetic electron transport in thylakoids or the
mitochondrial respiration. In this paper the lipid composition of the organic extracts of the green alga Chlamydomonas reinhardtii
and the diatom Cyclotella meneghiniana are compared by using matrix-assisted laser desorption and ionization time-of-flight
(MALDI-TOF) mass spectrometry (MS) in combination with thin-layer chromatography (TLC).
The combined methods enable quantitative evaluation of the individual lipid classes as well as the determination of the relative
acyl compositions. It will be shown that both algae differ in (a) the lipid classes, (b) the relative contribution of the individual
lipid classes and (c) the acyl compositions. Differences in the acyl composition concern particularly the mono- and digalactosyl
diacylglycerols. Glycerol-trimethylhomoserine and phosphatidylethanolamine are exclusively detected in the C. reinhardtii
extracts, whereas phosphatidylcholine is a characteristic lipid of C. meneghiniana. Furthermore, the proportion of the acidic lipids sulfoquinovosyl-diacylglycerol and phosphatidylglycerol is significantly higher in the diatom than in C. reinhardtii.
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