Das Projekt "Rationelle Zusammenstellung kataboler Segmente, um bessere bakterielle Biokatalysatoren zum Abbau von Chlor- und Nitroaromaten zu erhalten" wird vom Umweltbundesamt gefördert und von Gesellschaft für Biotechnologische Forschung mbH durchgeführt. This research project will attempt to characterize useful elements for the biological elimination of chloro- and nitrotoluenes and to identify bottlenecks which prevent the degradation for the recalcitrant compounds, followed by a selective manipulation of key genes to overcome the bottlenecks. The optimization will give rise to a set of catabolic segments which can be rationally combined to develop biocatalysts with new degradative capabilities and optimized performance. Analysis of biocatalyst performance and results of validation experiments will lead to further optimization procedures. The strategy will be applied to develop biocatalysts for predictable degradation of 2- and 3-nitro-, 2-chloro- as well as dichlorotoluenes, to the optimization of performance of 4-nitrotoluene degraders and to the assessment of this strategy for a variety of analogous compounds using the catabolic elements. The catabolic elements evolved in this project will be eventually used as a basis to improve further biocatalysts and the variety of tools developed in this project will be of general applicability in the generation of predictable biocatalysts. The overall project is broken down into three different work packages: 1) analysis of catabolic segments, the assessment of their usefulness for optimization procedures and the identification of critical steps. 2) the improvement and eventual optimization of isolated catabolic elements, and 3) testing the efficacy of the new biodegraders.