One more new Dr. rer. nat. from our group: Sven Basa

This Friday, Sven Basa received his degree certificates, pronouncing him a “Dr. rer. nat.” His family had come from Southern Germany to celebrate with him and of course, the whole group came to hood him. Sven had been an associated member of the Indo-German graduate school of Molecular and Cellular Glyco-Sciences, and he had contributed to the Indo-German “2+2” project on copper-loaded chitosan nanoparticles and biocontrol agents for sustainable crop plant protection. He had focused on the role of partially acetylated chitosan oligomers produced using partial enzymatic depolymerisation of well-defined chitosan polymers in inducing resistance reactions in higher plants. Already in the PolyModE project, we had hypothesised that sequence-specific chitosanolytic enzymes should be able to “read the chitosan code”, i.e. to produce different, specific chitosan oligomers with defined bioactivities depending on the pattern of acetylation of the polymer used as a substrate. At the time, we had neither the enzymes with known substrate specificities nor the chitosans with known patterns of acetylation to experimentally test this hypothesis. But during the time of Sven’s doctoral project, we developed the molecular genetic techniques required to produce such enzymes, and the mass-spectrometric fingerprinting tools to analyse their subsite specificities. Using these on chitosan polymers with known random pattern of acetylation, Sven was able to show for the first time ever that the pattern of acetylation of the chitosan oligomers thus produced crucially determines their biological activities. In fact, this is the first unequivocal evidence for the existence of the “chitosan code”. Our next task will be to publish this breakthrough result - for now, we have secured our scientific priority by pre-publication on ChemRxiv.