engleski

A common Mediterranean diatom shifts lipid and protein production under influence of relevant climate change stressors

The Mediterranean Sea is considered a climate change hotspot due to the specific physical and climatological properties that define the basin. The increasingly warm surface layer in the Mediterranean Sea, accompanied by a stronger oligotrophication, is reflected in the vulnerability of phytoplankton populations to introduced stresses. These changes in environmental conditions influence carbon allocation and remodeling of organic classes in phytoplankton. In this study, we subjected the diatom Chaetoceros pseudocurvisetus, abundant and ecologically important primary producer in the Mediterranean Sea, to a matrix of different temperature and nutrient conditions: 15 °C as optimal and 25 °C and 30 °C as temperature stress, and varying inorganic nitrogen (N) availability, mimicking optimal, eutrophic, and oligotrophic conditions. We examined the lipidomic response using thin-layer chromatography coupled with electrospray mass spectrometry, while the total protein content was quantified according to the modified Lowry method. The sampling timing proved to be crucial in the interpretation of data. During the exponential growth phase, no significant changes between C. pseudocurvisetus responses in different treatments were observed, while the following trends were established at the onset of the stationary phase. Bulk lipid content decreased with increasing temperature and decreasing available N in the medium. Protein production was strongly limited in oligotrophic conditions, and it remained constant at different growth temperatures, while it decreased with temperature in eutrophic and optimal N conditions. We found that the assessment of the protein-to- lipid ratio can provide a good insight into cell biochemistry. Changes in lipid and protein content have a profound effect on the wellness of an individual cell, however, alteration in their availability can impact the entire food web structure and health.

diatom, phytoplankton ; marine lipids ; lipid remodeling ; climate change

nije evidentirano