Influence of temperature and elevated carbon dioxide on the production of dimethylsulfoniopropionate and glycine betaine by marine phytoplankton

The sulfur metabolite dimethylsulfoniopropionate (DMSP) is the most important precursor of the climate relevant metabolite dimethylsulfide (DMS). It has thus gained interest in the context of climate change and several studies investigated the influence of elevated temperature and/or CO2 on DMSP in complex plankton communities. However, only little information about changes in response to these factors in single species is available. Therefore, we analyzed DMSP in different phytoplankton cultures (Thalassiosira pseudonana, Phaeodactylum tricornutum, Emiliania huxleyi) under the influence of increased temperature by 6 °C and elevated CO2 to 790 ppmv. In addition, we addressed glycine betaine (GBT) that fulfills a similar function as osmolyte like DMSP. In all cultures GBT concentrations increased at higher temperature and decreased at elevated CO2. In contrast, diatoms and prymnesiophytes revealed opposite trends for DMSP. In diatoms increased CO2 and temperature led to decreased DMSP concentrations, while rather elevated levels of this metabolite under the influence of these parameters were observed for E. huxleyi.