The group of biopolymers comprises a wide range of various different molecules. Their structure ranges from rather simple molecules to very complex, heterogenic polymers. They encompass many different biological functions, and in certain organisms, the same biopolymer can have a completely different physiological relevance.

We use Synechocystis sp. PCC 6803 as a model organism, since it can produce a variety of different biopolymers, including glycogen, poly-hydroxy-butyrate (PHB), cyanophycin and polyphosphate. This metabolic complexity is allowing Synechocystis to adapt its lifestyle to a wide range of different habitats and conditions. For example, it can grow under autotrophic, chemotrophic, phototrophic or fermenting conditions, depending on its environment.

However, for some of the biopolymers mentioned above, their physiological function or details of their metabolism remain unknown. Hence it is one objective of our working group to shed light on this fascinating and at the same time complex metabolic network.

Additionally, some of these biopolymers are of high industrial relevance. PHB, for instance, can serve as a biodegradable, carbon neutral plastic substitute, while cyanophycin can be used as a food supplement, to just name a few examples.

Our current working projects include the following:

• Cyanophycin metabolism, regulation and its physiological function
• PHB metabolism, regulation and its physiological function
• Glycogen metabolism and its role during nitrogen starvation
• Regulatory connection between intracellular nitrogen and carbon cycle