Lipidomics of Thalassiosira pseudonana Under Phosphorus Stress Reveal Underlying Phospholipid Substitution Dynamics and Novel Diglycosylceramide Substitutes.

Lipidomics of Thalassiosira pseudonana Under Phosphorus Stress Reveal Underlying Phospholipid Substitution Dynamics and Novel Diglycosylceramide Substitutes. Appl Environ Microbiol. 2018 Jan 05;: Authors: Hunter JE, Brandsma J, Dymond MK, Koster G, Moore CM, Postle AD, Mills RA, Attard GS Abstract Phytoplankton substitute phosphorus (P) containing lipids with non-P analogues boosting growth in P-limited oceans. In the model diatom Thalassiosira pseudonana, lipid headgroup substitution dynamics are well described, but those of the individual lipids, varying in fatty acids, are unknown. Moreover, the behaviour of lipids outside of the common headgroup classes, and the relationship between lipid substitution and cellular particulate organic P (POP) are yet to be reported. We investigated these through the mass spectrometric lipidomics of P replete (P+) and depleted (P-) T. pseudonana cultures. Non-lipidic POP was depleted rapidly by the initiation of P stress, followed thereafter by cessation of P-lipid biosynthesis and per-cell reduction in P-lipid of successive generations. Minor P-lipid degradative breakdown was observed, releasing P for other processes, but most remained intact. This may confer an advantage to efficient heterotrophic lipid consumers in P limited oceans. Glycerophosphatidylcholine (PC), the predominant P-lipid, was similar in composition to its betaine substitute lipid. During substitution, PC per cell was less abund...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Tags: Appl Environ Microbiol Source Type: research