Biological role of polyhydroxyalkanoates in cyanobacteria

Cyanobacteria are ubiquitous Gram-negative prokaryotes capable of performing oxygenic photosynthesis. These microbes are extremely environmentally important since they are crucial players in oxygen generation and CO2 and N2 fixation on the Earth. Furthermore, cyanobacteria are also employed in biotechnology. Numerous cyanobacteria, similarly as many non-photosynthesizing prokaryotes, accumulate polyhydroxyalkanoates (PHA), polyesters which serve primarily as storage materials. Nevertheless, according to latest research reports with heterotrophs, PHA also represents important protective metabolites against numerous stress factors. The aim of this project is to study biological role of PHA in cyanobacteria with respect to cells resistance and robustness against various environmentally relevant stressors and explain potential protective mechanisms of PHA. We will also investigate the impact of stress on PHA metabolism, physiology, morphology, biochemistry and biophysics of cyanobacterial cells and evaluate evolutionary importance of PHA for cyanobacteria during adaptation to stress.