Comparative metabolomics of the diatom Skeletonema marinoi in different growth phases

We introduce a rigorously validated protocol based on extraction, derivatisation and GC/MS for the analysis of diatom metabolomes. Using this methodology we characterised general patterns of the metabolism of the diatom Skeletonema marinoi during different growth phases. Canonical analysis of principal coordinate revealed clearly that the intracellular metabolites differ between exponential, stationary and declining phase. In addition, diurnal variation during the exponential phase was observed. A detailed analysis of the metabolic changes is presented and discussed in the context of previous physiological studies of diatoms. The observed variability in metabolites has a significant consequence for further physiological and ecological studies. Investigations have to take into account that diatom metabolism is a highly dynamic process and that food quality, chemical defence and also the production of signal molecules might be dependent on different growth phases or diurnal variations. The introduced protocol is in general suitable for the monitoring of microalgae and has also the potential to be applied to complex plankton communities.