Climate change (including temperature increase and acidification of waters - due to increased atmospheric CO2) affects water quality and the fundamental biology of the planet. Through this project we aim to decipher the evolutionary responses to warming and acidification in three key genera of cyanobacteria: Microcystis, Anabaena and Planktothrix. Cyanobacteria are globally distributed phytoplanktonic organisms that produce a significant proportion of atmospheric oxygen, with some species generating toxic blooms at the surface of waters. Understanding the response of cyanobacteria to climate change is crucial for analysing the long-term stability of aquatic ecosystems and the occurrence of toxic blooms, but this is largely unknown. Predictions based on computer modelling are generally based on short-term experiments, which, however, do not provide information on the evolutionary potential of these organisms.

The objectives of this project are: 1) to analyse the adaptive potential of cyanobacteria to elevated temperature/acidification; 2) to investigate the extent to which pre-adaptation influences evolutionary potential; 3) to test whether adaptation affects the toxic potential of cyanobacteria; 4) to analyse how the competitive abilities of cyanobacteria are affected by/ affect natural communities of microorganisms. To this end we will measure, in a long-term experiment, the response of different cyanobacterial lineages to increased temperature/acidification. Subsequently, the organisms will be combined in mixed cultures, and we will test the extent to which previous experiments affect their growth, including in lake water. In addition to phenotypic traits, we will utilise DNA sequencing, gene expression and DNA barcoding techniques. This project will provide valuable information about the ecological health of lakes in the future under climate change.