The PETRA IV project at DESY (Deutsches Elektronen Synchrotron) aims at building a unique synchrotron light source to provide beams of hard X-rays with unprece-dented coherence properties that can be focused to dimensions in the nanometer-regime. An optimization of the girder structure is necessary to reduce the impact of ambient vibrations on the particle beam. For this purpose, several numerical approaches have been made to simultaneously reach natural frequencies above 50 Hz, a high stiffness and a low mass. In order to define an optimal girder support, a paramet-ric study was conducted varying both the number and location of support points. Based on the resulting ar-rangement of support points, topology optimizations were performed to achieve a high stiffness and a high first natural frequency. The following transformation of the results into parametric constructions allowed further par-ametric studies to find optimal geometry parameters leading to the aimed girder properties. In addition to that, bio-inspired structures based on marine organisms were applied to the girder which likewise resulted in improved girder properties.