Das Projekt "Abbau von biosynthetischen Kunststoffen durch Pilze" wird vom Umweltbundesamt gefördert und von Universität Regensburg, Institut für Botanik, Lehrstuhl für Botanik durchgeführt. The current problems with decreasing fossile resources and increasing environmental pollution by petrochemical-based plastics have stimulated investigations to find biosynthetic materials which are also biodegradable. Bacterial reserve materials such as polyhydrxyalkanoates (PHA) have been discovered to possess thermoplastic properties and can be synthesized from renewable resources. Poly-beta-hydroxybutyric acid (PHB) presently is the most promising PHA and is already industrially produced (BIOPOL, ICI-England) and used as packaging material (WELLA-Germany). PHA and its copolymers have been shown to be completely biodegradable by bacteria to carbon dioxide, water and energy. For the participation of fungi, the other important group of biodegrading microorganisms, however, only circumstantial evidence exists. Since not only terrestrial waste pits and freshwater bodies but also the oceans and estuares today unfortunately serve as major waste dumps, it seems important to elucidate the role of fungi in PHA degradation in terrestrial and freshwater bodies as well as in marine ecosystems before this material is used to any greater extent. For this purpose the following investigations already have been conducted in our group: 1) Development of qualitative and semiqauntitative degradation tests. 2) Screening of culture collections of terrestrial and marine fungi for degradative activity. 3) In-field tests at 10 different terrestrial and freshwater sites. 4) Scanning electron microscopy of the degradation process.