Exopolysaccharides are important agents for bacterial fitness, masking against eukaryotic defense mechanisms, and for surface attachment processes. In the major focus of our research group is the polyfructosyl macromolecule, levan. This polymer is synthesized by the extra-cellular enzyme, levansucrase. We identified the transcriptional start site for its gene. Next we could successfully apply the method of DNA affinity chromatography to identify proteins repressing the expression of levansucrase. The role of an activator protein in this process was demonstrated. The activator protein scavanges a repressor under inductive conditions. Excessive work on these topics had prompted Horizon Press to invite Ullrich as editor of a book entitled “Bacterial polysaccharides – Current Innovations and future trends” published in 2009.